Programs & Examples On #Relate

Jquery assiging class to th in a table

You had thead in your selector, but there is no thead in your table. Also you had your selectors backwards. As you mentioned above, you wanted to be adding the tr class to the th, not vice-versa (although your comment seems to contradict what you wrote up above).

$('tr th').each(function(index){     if($('tr td').eq(index).attr('class') != ''){         // get the class of the td         var tdClass = $('tr td').eq(index).attr('class');         // add it to this th         $(this).addClass(tdClass );     } }); 

Fiddle

SameSite warning Chrome 77

To elaborate on Rahul Mahadik's answer, this works for MVC5 C#.NET:

AllowSameSiteAttribute.cs

public class AllowSameSiteAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        var response = filterContext.RequestContext.HttpContext.Response;

        if(response != null)
        {
            response.AddHeader("Set-Cookie", "HttpOnly;Secure;SameSite=Strict");
            //Add more headers...
        }

        base.OnActionExecuting(filterContext);
    }
}

HomeController.cs

    [AllowSameSite] //For the whole controller
    public class UserController : Controller
    {
    }

or

    public class UserController : Controller
    {
        [AllowSameSite] //For the method
        public ActionResult Index()
        {
            return View();
        }
    }

What's the net::ERR_HTTP2_PROTOCOL_ERROR about?

This error is currently being fixed: https://chromium-review.googlesource.com/c/chromium/src/+/2001234

But it helped me, changing nginx settings:

  • turning on gzip;
  • add_header 'Cache-Control' 'no-store, no-cache, must-revalidate, proxy-revalidate, max-age=0';
  • expires off;

In my case, Nginx acts as a reverse proxy for Node.js application.

React Native Error: ENOSPC: System limit for number of file watchers reached

Please refer this link[1]. Visual Studio code has mentioned a brief explanation for this error message. I also encountered the same error. Adding the below parameter in the relavant file will fix this issue.

 fs.inotify.max_user_watches=524288

[1] https://code.visualstudio.com/docs/setup/linux#_visual-studio-code-is-unable-to-watch-for-file-changes-in-this-large-workspace-error-enospc

Browserslist: caniuse-lite is outdated. Please run next command `npm update caniuse-lite browserslist`

I'm not exactly sure where my problem was, but I believe it was because I was using the same global packages from both npm and Yarn.

I uninstalled all the npm global packages, then when using yarn commands once again, the problem was gone.

To see global packages installed...

for npm:

npm ls -g --depth=0

for Yarn:

yarn global list

I then uninstalled each package I saw in the npm listing, using:

npm uninstall -g <package-name>

react hooks useEffect() cleanup for only componentWillUnmount?

function LegoComponent() {

  const [lego, setLegos] = React.useState([])

  React.useEffect(() => {
    let isSubscribed = true
    fetchLegos().then( legos=> {
      if (isSubscribed) {
        setLegos(legos)
      }
    })
    return () => isSubscribed = false
  }, []);

  return (
    <ul>
    {legos.map(lego=> <li>{lego}</li>)}
    </ul>
  )
}

In the code above, the fetchLegos function returns a promise. We can “cancel” the promise by having a conditional in the scope of useEffect, preventing the app from setting state after the component has unmounted.

Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function.

How to make an AlertDialog in Flutter?

Simply used this custom dialog class which field you not needed to leave it or make it null so this customization you got easily.

import 'package:flutter/material.dart';

class CustomAlertDialog extends StatelessWidget {
  final Color bgColor;
  final String title;
  final String message;
  final String positiveBtnText;
  final String negativeBtnText;
  final Function onPostivePressed;
  final Function onNegativePressed;
  final double circularBorderRadius;

  CustomAlertDialog({
    this.title,
    this.message,
    this.circularBorderRadius = 15.0,
    this.bgColor = Colors.white,
    this.positiveBtnText,
    this.negativeBtnText,
    this.onPostivePressed,
    this.onNegativePressed,
  })  : assert(bgColor != null),
        assert(circularBorderRadius != null);

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: title != null ? Text(title) : null,
      content: message != null ? Text(message) : null,
      backgroundColor: bgColor,
      shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(circularBorderRadius)),
      actions: <Widget>[
        negativeBtnText != null
            ? FlatButton(
                child: Text(negativeBtnText),
                textColor: Theme.of(context).accentColor,
                onPressed: () {
                  Navigator.of(context).pop();
                  if (onNegativePressed != null) {
                    onNegativePressed();
                  }
                },
              )
            : null,
        positiveBtnText != null
            ? FlatButton(
                child: Text(positiveBtnText),
                textColor: Theme.of(context).accentColor,
                onPressed: () {
                  if (onPostivePressed != null) {
                    onPostivePressed();
                  }
                },
              )
            : null,
      ],
    );
  }
}

Usage:

var dialog = CustomAlertDialog(
  title: "Logout",
  message: "Are you sure, do you want to logout?",
  onPostivePressed: () {},
  positiveBtnText: 'Yes',
  negativeBtnText: 'No');
showDialog(
  context: context,
  builder: (BuildContext context) => dialog);

Output:

enter image description here

Xcode 10: A valid provisioning profile for this executable was not found

I had the same issue (XCode 11) and nothing worked what was written here.

My issue was that I had iOS Beta (13.3) on my Phone. After reverting that everything worked fine again.


Idea: Maybe the device caches some Information about the provisioning profile too, so a factory reset of the phone might also fix it?

curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number

* Uses proxy env variable http_proxy == 'https://proxy.in.tum.de:8080'   
                                         ^^^^^

The https:// is wrong, it should be http://. The proxy itself should be accessed by HTTP and not HTTPS even though the target URL is HTTPS. The proxy will nevertheless properly handle HTTPS connection and keep the end-to-end encryption. See HTTP CONNECT method for details how this is done.

You must add a reference to assembly 'netstandard, Version=2.0.0.0

Those who are not having web.config file. Output Type other than web application. update the project file (.csproj) with below give code.

It may cause due to adding/removing the .netframework in improper way or it may broke unexpected way.

  <ItemGroup>
    <Reference Include="netstandard" />
  </ItemGroup>

Output Type

  • Console application
  • Class Library

'pip install' fails for every package ("Could not find a version that satisfies the requirement")

Support for TLS 1.0 and 1.1 was dropped for PyPI. If your system does not use a more recent version, it could explain your error.

Could you try reinstalling pip system-wide, to update your system dependencies to a newer version of TLS?

This seems to be related to Unable to install Python libraries

See Dominique Barton's answer:

Apparently pip is trying to access PyPI via HTTPS (which is encrypted and fine), but with an old (insecure) SSL version. Your system seems to be out of date. It might help if you update your packages.

On Debian-based systems I'd try:

apt-get update && apt-get upgrade python-pip

On Red Hat Linux-based systems:

yum update python-pip # (or python2-pip, at least on Red Hat Linux 7)

On Mac:

sudo easy_install -U pip

You can also try to update openssl separately.

Angular 5 ngHide ngShow [hidden] not working

Try this

 <input class="txt" type="password" [(ngModel)]="input_pw" [hidden]="isHidden">

What could cause an error related to npm not being able to find a file? No contents in my node_modules subfolder. Why is that?

It might be related to corruption in Angular Packages or incompatibility of packages.

Please follow the below steps to solve the issue.

Update

ASP.NET Boilerplate suggests here to use yarn because npm has some problems. It is slow and can not consistently resolve dependencies, yarn solves those problems and it is compatible to npm as well.

No provider for HttpClient

Add HttpModule and HttpClientModule in both imports and providers in app.module.ts solved the issue. imports -> import {HttpModule} from "@angular/http"; import {HttpClientModule} from "@angular/common/http";

Failed to run sdkmanager --list with Java 9

Define home directories of different JDK versions in your .bashrc or .zshrc:

export JAVA_8_HOME=$(/usr/libexec/java_home -v1.8)
export JAVA_14_HOME=$(/usr/libexec/java_home -v14)

First of all use JDK version 8. Put this line the top of sdkmanager file:

export JAVA_HOME=$JAVA_8_HOME

Switch back to JDK version 14. Put this line the bottom of sdkmanager file:

export JAVA_HOME=$JAVA_14_HOME

How to clear react-native cache?

Here's a great discussion on GitHub which helped me a lot. Clearing the Cache of your React Native Project by Jarret Moses

There are solutions for 4 different instances.

  1. RN <0.50 -
    watchman watch-del-all && rm -rf $TMPDIR/react-* && rm -rf node_modules/ && npm cache clean && npm install && npm start -- --reset-cache

  2. RN >=0.50 - watchman watch-del-all && rm -rf $TMPDIR/react-native-packager-cache-* && rm -rf $TMPDIR/metro-bundler-cache-* && rm -rf node_modules/ && npm cache clean && npm install && npm start -- --reset-cache

  3. NPM >=5 - watchman watch-del-all && rm -rf $TMPDIR/react-* && rm -rf node_modules/ && npm cache verify && npm install && npm start -- --reset-cache
  4. Windows - del %appdata%\Temp\react-native-* & cd android & gradlew clean & cd .. & del node_modules/ & npm cache clean --force & npm install & npm start -- --reset-cache

The solution is similar to Vikram Biwal's Answer.

And there is a discussion below in the given link, so even if the above 4 cases don't work for you, you can scroll through and find a possible solution.

Android 8.0: java.lang.IllegalStateException: Not allowed to start service Intent

As @kosev said in his answer you can use JobIntentService. But I use an alternative solution - I catch IllegalStateException and start the service as foreground. For example, this function starts my service:

@JvmStatic
protected fun startService(intentAction: String, serviceType: Class<*>, intentExtraSetup: (Intent) -> Unit) {
    val context = App.context
    val intent = Intent(context, serviceType)
    intent.action = intentAction
    intentExtraSetup(intent)
    intent.putExtra(NEED_FOREGROUND_KEY, false)

    try {
        context.startService(intent)
    }
    catch (ex: IllegalStateException) {
        intent.putExtra(NEED_FOREGROUND_KEY, true)
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            context.startForegroundService(intent)
        }
        else {
            context.startService(intent)
        }
    }
}

and when I process Intent I do such thing:

override fun onHandleIntent(intent: Intent?) {
    val needToMoveToForeground = intent?.getBooleanExtra(NEED_FOREGROUND_KEY, false) ?: false
    if(needToMoveToForeground) {
        val notification = notificationService.createSyncServiceNotification()
        startForeground(notification.second, notification.first)

        isInForeground = true
    }

    intent?.let {
        getTask(it)?.process()
    }
}

Failed to resolve: com.google.android.gms:play-services in IntelliJ Idea with gradle

Add this to your project-level build.gradle file:

repositories {
    maven {
        url "https://maven.google.com"
    }
}

It worked for me

Update .NET web service to use TLS 1.2

PowerBI Embedded requires TLS 1.2.

The answer above by Etienne Faucher is your solution. quick link to above answer... quick link to above answer... ( https://stackoverflow.com/a/45442874 )

PowerBI Requires TLS 1.2 June 2020 - This Is your Answer - Consider Forcing your IIS runtime to get up to 4.6 to force the default TLS 1.2 behavior you are looking for from the framework. The above answer gives you a config change only solution.

Symptoms: Forced Closed Rejected TCP/IP Connection to Microsoft PowerBI Embedded that just shows up all of a sudden across your systems.

These PowerBI Calls just stop working with a Hard TCP/IP Close error like a firewall would block a connection. Usually the auth steps work - it is when you hit the service for specific workspace and report id's that it fails.

This is the 2020 note from Microsoft PowerBI about TLS 1.2 required

PowerBIClient

methods that show this problem

GetReportsInGroupAsync GetReportsInGroupAsAdminAsync GetReportsAsync GetReportsAsAdminAsync Microsoft.PowerBI.Api HttpClientHandler Force TLS 1.1 TLS 1.2

Search Error Terms to help people find this: System.Net.Http.HttpRequestException: An error occurred while sending the request System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

laravel Unable to prepare route ... for serialization. Uses Closure

the solustion when we use routes like this:

Route::get('/', function () {
    return view('welcome');
});

laravel call them Closure so you cant optimize routes uses as Closures you must route to controller to use php artisan optimize

How to completely uninstall kubernetes

If you are clearing the cluster so that you can start again, then, in addition to what @rib47 said, I also do the following to ensure my systems are in a state ready for kubeadm init again:

kubeadm reset -f
rm -rf /etc/cni /etc/kubernetes /var/lib/dockershim /var/lib/etcd /var/lib/kubelet /var/run/kubernetes ~/.kube/*
iptables -F && iptables -X
iptables -t nat -F && iptables -t nat -X
iptables -t raw -F && iptables -t raw -X
iptables -t mangle -F && iptables -t mangle -X
systemctl restart docker

You then need to re-install docker.io, kubeadm, kubectl, and kubelet to make sure they are at the latest versions for your distribution before you re-initialize the cluster.

EDIT: Discovered that calico adds firewall rules to the raw table so that needs clearing out as well.

Val and Var in Kotlin

Do you need to change a variable or set it permanently?

  • A good example if it is something like val pi5places = 3.14159 you would set it as val. Is there a possibility that you need to change that variable now or later, then you would set it as var.

  • For example : The color of a car, can be var colorCar = green. Later you can change that colorCar = blue, where as a val, you can not.

  • Responses here regarding mutable and immutable is fine, but may be scary if these terms are not well known or just getting into learning how to program.

Android Room - simple select query - Cannot access database on the main thread

Update: I also got this message when I was trying to build a query using @RawQuery and SupportSQLiteQuery inside the DAO.

@Transaction
public LiveData<List<MyEntity>> getList(MySettings mySettings) {
    //return getMyList(); -->this is ok

    return getMyList(new SimpleSQLiteQuery("select * from mytable")); --> this is an error

Solution: build the query inside the ViewModel and pass it to the DAO.

public MyViewModel(Application application) {
...
        list = Transformations.switchMap(searchParams, params -> {

            StringBuilder sql;
            sql = new StringBuilder("select  ... ");

            return appDatabase.rawDao().getList(new SimpleSQLiteQuery(sql.toString()));

        });
    }

Or...

You should not access the database directly on the main thread, for example:

 public void add(MyEntity item) {
     appDatabase.myDao().add(item); 
 }

You should use AsyncTask for update, add, and delete operations.

Example:

public class MyViewModel extends AndroidViewModel {

    private LiveData<List<MyEntity>> list;

    private AppDatabase appDatabase;

    public MyViewModel(Application application) {
        super(application);

        appDatabase = AppDatabase.getDatabase(this.getApplication());
        list = appDatabase.myDao().getItems();
    }

    public LiveData<List<MyEntity>> getItems() {
        return list;
    }

    public void delete(Obj item) {
        new deleteAsyncTask(appDatabase).execute(item);
    }

    private static class deleteAsyncTask extends AsyncTask<MyEntity, Void, Void> {

        private AppDatabase db;

        deleteAsyncTask(AppDatabase appDatabase) {
            db = appDatabase;
        }

        @Override
        protected Void doInBackground(final MyEntity... params) {
            db.myDao().delete((params[0]));
            return null;
        }
    }

    public void add(final MyEntity item) {
        new addAsyncTask(appDatabase).execute(item);
    }

    private static class addAsyncTask extends AsyncTask<MyEntity, Void, Void> {

        private AppDatabase db;

        addAsyncTask(AppDatabase appDatabase) {
            db = appDatabase;
        }

        @Override
        protected Void doInBackground(final MyEntity... params) {
            db.myDao().add((params[0]));
            return null;
        }

    }
}

If you use LiveData for select operations, you don't need AsyncTask.

I am getting an "Invalid Host header" message when connecting to webpack-dev-server remotely

I found out, that I need to set the public property of devServer, to my request's host value. Being that it will be displayed at that external address.

So I needed this in my webpack.config.js

devServer: {
  compress: true,
  public: 'store-client-nestroia1.c9users.io' // That solved it
}

Another solution is using it on the CLI:

webpack-dev-server --public $C9_HOSTNAME <-- var for Cloud9 external IP

Prevent content from expanding grid items

The previous answer is pretty good, but I also wanted to mention that there is a fixed layout equivalent for grids, you just need to write minmax(0, 1fr) instead of 1fr as your track size.

how to get the ipaddress of a virtual box running on local machine

Login to virtual machine use below command to check ip address. (anyone will work)

  1. ifconfig
  2. ip addr show

If you used NAT for your virtual machine settings(your machine ip will be 10.0.2.15), then you have to use port forwarding to connect to machine. IP address will be 127.0.0.1

If you used bridged networking/Host only networking, then you will have separate Ip address. Use that IP address to connect virtual machine

Python - AttributeError: 'numpy.ndarray' object has no attribute 'append'

Numpy arrays do not have an append method. Use the Numpy append function instead:

import numpy as np

array_3 = np.append(array_1, array_2, axis=n)
# you can either specify an integer axis value n or remove the keyword argument completely

For example, if array_1 and array_2 have the following values:

array_1 = np.array([1, 2])
array_2 = np.array([3, 4])

If you call np.append without specifying an axis value, like so:

array_3 = np.append(array_1, array_2)

array_3 will have the following value:

array([1, 2, 3, 4])

Else, if you call np.append with an axis value of 0, like so:

array_3 = np.append(array_1, array_2, axis=0)

array_3 will have the following value:

 array([[1, 2],
        [3, 4]]) 

More information on the append function here: https://docs.scipy.org/doc/numpy/reference/generated/numpy.append.html

Change line width of lines in matplotlib pyplot legend

@ImportanceOfBeingErnest 's answer is good if you only want to change the linewidth inside the legend box. But I think it is a bit more complex since you have to copy the handles before changing legend linewidth. Besides, it can not change the legend label fontsize. The following two methods can not only change the linewidth but also the legend label text font size in a more concise way.

Method 1

import numpy as np
import matplotlib.pyplot as plt

# make some data
x = np.linspace(0, 2*np.pi)

y1 = np.sin(x)
y2 = np.cos(x)

# plot sin(x) and cos(x)
fig = plt.figure()
ax  = fig.add_subplot(111)
ax.plot(x, y1, c='b', label='y1')
ax.plot(x, y2, c='r', label='y2')

leg = plt.legend()
# get the individual lines inside legend and set line width
for line in leg.get_lines():
    line.set_linewidth(4)
# get label texts inside legend and set font size
for text in leg.get_texts():
    text.set_fontsize('x-large')

plt.savefig('leg_example')
plt.show()

Method 2

import numpy as np
import matplotlib.pyplot as plt

# make some data
x = np.linspace(0, 2*np.pi)

y1 = np.sin(x)
y2 = np.cos(x)

# plot sin(x) and cos(x)
fig = plt.figure()
ax  = fig.add_subplot(111)
ax.plot(x, y1, c='b', label='y1')
ax.plot(x, y2, c='r', label='y2')

leg = plt.legend()
# get the lines and texts inside legend box
leg_lines = leg.get_lines()
leg_texts = leg.get_texts()
# bulk-set the properties of all lines and texts
plt.setp(leg_lines, linewidth=4)
plt.setp(leg_texts, fontsize='x-large')
plt.savefig('leg_example')
plt.show()

The above two methods produce the same output image:

output image

Unity Scripts edited in Visual studio don't provide autocomplete

I hit the same issues today using Visual Studio 2017 15.4.5 with Unity 2017.

I was able to fix the issue by right clicking on the project in Visual Studio and changing the target framework from 3.5 to 4.5.

Hope this helps anyone else in a similar scenario.

Vertical Align Center in Bootstrap 4

you can vertically align your container by making the parent container flex and adding align-items:center:

body {
  display:flex;
  align-items:center;
}

Updated Pen

How to implement a Navbar Dropdown Hover in Bootstrap v4?

1. Remove data-toggle="dropdown" attribute (so click will not open dropdown menu)

2. Add :hover pseudo-class to show dropdown-menu

_x000D_
_x000D_
.dropdown:hover .dropdown-menu {display: block;}
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>_x000D_
_x000D_
<nav class="navbar navbar-toggleable-md navbar-light bg-faded">_x000D_
  <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation">_x000D_
    <span class="navbar-toggler-icon"></span>_x000D_
  </button>_x000D_
  <a class="navbar-brand" href="#">Navbar</a>_x000D_
  <div class="collapse navbar-collapse" id="navbarNavDropdown">_x000D_
    <ul class="navbar-nav">_x000D_
      <li class="nav-item active">_x000D_
        <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>_x000D_
      </li>_x000D_
      <li class="nav-item dropdown">_x000D_
        <a class="nav-link dropdown-toggle" href="http://example.com" id="navbarDropdownMenuLink" aria-haspopup="true" aria-expanded="false">_x000D_
          Dropdown link_x000D_
        </a>_x000D_
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">_x000D_
          <a class="dropdown-item" href="#">Action</a>_x000D_
          <a class="dropdown-item" href="#">Another action</a>_x000D_
          <a class="dropdown-item" href="#">Something else here</a>_x000D_
        </div>_x000D_
      </li>_x000D_
      <li class="nav-item">_x000D_
        <a class="nav-link" href="#">Features</a>_x000D_
      </li>_x000D_
      <li class="nav-item">_x000D_
        <a class="nav-link" href="#">Pricing</a>_x000D_
      </li>_x000D_
    </ul>_x000D_
  </div>_x000D_
</nav>
_x000D_
_x000D_
_x000D_

How to create multiple page app using react

This is a broad question and there are multiple ways you can achieve this. In my experience, I've seen a lot of single page applications having an entry point file such as index.js. This file would be responsible for 'bootstrapping' the application and will be your entry point for webpack.

index.js

import React from 'react';
import ReactDOM from 'react-dom';
import Application from './components/Application';

const root = document.getElementById('someElementIdHere');

ReactDOM.render(
  <Application />,
  root,
);

Your <Application /> component would contain the next pieces of your app. You've stated you want different pages and that leads me to believe you're using some sort of routing. That could be included into this component along with any libraries that need to be invoked on application start. react-router, redux, redux-saga, react-devtools come to mind. This way, you'll only need to add a single entry point into your webpack configuration and everything will trickle down in a sense.

When you've setup a router, you'll have options to set a component to a specific matched route. If you had a URL of /about, you should create the route in whatever routing package you're using and create a component of About.js with whatever information you need.

pytest cannot import module while python can

Found the answer:

DO NOT put a __init__.py file in a folder containing TESTS if you plan on using pytest. I had one such file, deleting it solved the problem.

This was actually buried in the comments to the second answer of PATH issue with pytest 'ImportError: No module named YadaYadaYada' so I did not see it, hope it gets more visibility here.

WebSocket connection failed: Error during WebSocket handshake: Unexpected response code: 400

The currently accepted solution is misleading.

According to the official documentation, adding the transports: [ 'websocket' ] option effectively removes the ability to fallback to long-polling when the websocket connection cannot be established. This option is what makes socket.io so robust in the first place because it can adapt to many scenarios.

In that particular case where one wishes to solely rely on websockets, directly using the WebSocket API is recommended.

For other cases (supposedly most users), this is most likely a reverse proxy/server configuration problem.

The official documentation suggests the following depending on your environment:

NginX configuration

http {
  server {
    listen 3000;
    server_name io.yourhost.com;

    location / {
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $host;

      proxy_pass http://nodes;

      # enable WebSockets
      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection "upgrade";
    }
  }

  upstream nodes {
    # enable sticky session based on IP
    ip_hash;

    server app01:3000;
    server app02:3000;
    server app03:3000;
  }
}

Apache HTTPD configuration

Header add Set-Cookie "SERVERID=sticky.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED

<Proxy "balancer://nodes_polling">
    BalancerMember "http://app01:3000" route=app01
    BalancerMember "http://app02:3000" route=app02
    BalancerMember "http://app03:3000" route=app03
    ProxySet stickysession=SERVERID
</Proxy>

<Proxy "balancer://nodes_ws">
    BalancerMember "ws://app01:3000" route=app01
    BalancerMember "ws://app02:3000" route=app02
    BalancerMember "ws://app03:3000" route=app03
    ProxySet stickysession=SERVERID
</Proxy>

RewriteEngine On
RewriteCond %{HTTP:Upgrade} =websocket [NC]
RewriteRule /(.*) balancer://nodes_ws/$1 [P,L]
RewriteCond %{HTTP:Upgrade} !=websocket [NC]
RewriteRule /(.*) balancer://nodes_polling/$1 [P,L]

ProxyTimeout 3

HAProxy configuration

listen chat
  bind *:80
  default_backend nodes

backend nodes
  option httpchk HEAD /health
  http-check expect status 200
  cookie io prefix indirect nocache # using the `io` cookie set upon handshake
  server app01 app01:3000 check cookie app01
  server app02 app02:3000 check cookie app02
  server app03 app03:3000 check cookie app03

Also worth reading this on upgrading connections in HAProxy.

For more details please refer to the official documentation link above.

EDIT:

Varnish (source here)

sub vcl_recv {
    if (req.http.upgrade ~ "(?i)websocket") {
        return (pipe);
    }
}

sub vcl_pipe {
    if (req.http.upgrade) {
        set bereq.http.upgrade = req.http.upgrade;
        set bereq.http.connection = req.http.connection;
    }
}

"ssl module in Python is not available" when installing package with pip3

Downgrading openssl worked for me,

brew switch openssl 1.0.2s

How to turn on/off MySQL strict mode in localhost (xampp)?

To change it permanently in Windows (10), edit the my.ini file. To find the my.ini file, look at the path in the Windows server. E.g. for my MySQL 5.7 instance, the service is MYSQL57, and in this service's properties the Path to executable is:

"C:\Program Files\MySQL\MySQL Server 5.7\bin\mysqld.exe" --defaults-file="C:\ProgramData\MySQL\MySQL Server 5.7\my.ini" MySQL57

I.e. edit the my.ini file in C:\ProgramData\MySQL\MySQL Server 5.7\. Note that C:\ProgramData\ is a hidden folder in Windows (10). My file has the following lines of interest:

# Set the SQL mode to strict
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

Remove STRICT_TRANS_TABLES, from this sql-mode line, save the file and restart the MYSQL57 service. Verify the result by executing SHOW VARIABLES LIKE 'sql_mode'; in a (new) MySQL Command Line Client window.

(I found the other answers and documents on the web useful, but none of them seem to tell you where to find the my.ini file in Windows.)

What's the source of Error: getaddrinfo EAI_AGAIN?

The OP's error specifies a host (my-store.myshopify.com). The error I encountered is the same in all respects except that no domain is specified.

My solution may help others who are drawn here by the title "Error: getaddrinfo EAI_AGAIN"

I encountered the error when trying to serve a NodeJs & VueJs app from a different VM from where the code was developed originally.

The file vue.config.js read :

 module.exports = {
   devServer: {
     host: 'tstvm01',
     port: 3030,
   },
 };

When served on the original machine the start up output is :

App running at:
- Local:   http://tstvm01:3030/ 
- Network: http://tstvm01:3030/

Using the same settings on a VM tstvm07 got me a very similar error to the one the OP describes:

 INFO  Starting development server...
 10% building modules 1/1 modules 0 activeevents.js:183                              
      throw er; // Unhandled 'error' event
      ^

Error: getaddrinfo EAI_AGAIN
    at Object._errnoException (util.js:1022:11)
    at errnoException (dns.js:55:15)
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:92:26)

If it ain't already obvious, changing vue.config.js to read ...

 module.exports = {
   devServer: {
     host: 'tstvm07',
     port: 3030,
   },
 };

... solved the problem.

Access multiple viewchildren using @viewchild

Use @ViewChildren from @angular/core to get a reference to the components

template

<div *ngFor="let v of views">
    <customcomponent #cmp></customcomponent>
</div>

component

import { ViewChildren, QueryList } from '@angular/core';

/** Get handle on cmp tags in the template */
@ViewChildren('cmp') components:QueryList<CustomComponent>;

ngAfterViewInit(){
    // print array of CustomComponent objects
    console.log(this.components.toArray());
}

l?i?v?e? ?d?e?m?o?

How do I select which GPU to run a job on?

You can also set the GPU in the command line so that you don't need to hard-code the device into your script (which may fail on systems without multiple GPUs). Say you want to run your script on GPU number 5, you can type the following on the command line and it will run your script just this once on GPU#5:

CUDA_VISIBLE_DEVICES=5, python test_script.py

Error : getaddrinfo ENOTFOUND registry.npmjs.org registry.npmjs.org:443

Things to try:

  1. make sure you have internet connection: ping 8.8.8.8
  2. make sure you have DNS resolver working: ping www.google.com
  3. make sure you can access registry.npmjs.org: ping registry.npmjs.org
  4. make sure you can connect via https.

Try in your browser: https://registry.npmjs.org/

Make sure you are trying to connect to:

  • registry.npmjs.org

and not to:

  • "registry.npmjs.org registry.npmjs.org:443"

or some other weird string composed of few hostnames, because it's weird that the resolver complains about a hostnames that includes a port number, which it shouldn't care about. Ok, I tested and it should look like this for hosts that are not found.

Update

From your comment to this answer it seems that you are not directly connected to the internet if you can't even ping 8.8.8.8.

If you are using a proxy to access the Web, then you also have to configure npm to use it. Use:

npm config set proxy http://example.com:8080
npm config set https-proxy http://example.com:8080

but instead of http://example.com:8080 use what you actually need in your company - ask someone or see how your browser is configured.

To see your proxy configuration in Chrome, see this.

Update 2

If you can access https://registry.npmjs.org/ in your browser but you cannot run ping registry.npmjs.org then it means that your browser must be configured to use a proxy, or other programs than your browser must be restricted from using the internet.

In any case, you should ask someone in your company about it because most likely you either need to use a specific proxy or someone needs to lift the restriction from your npm and allow it to access the network.

The network access can be blocked by a firewall installed on your computer or a router in your network. It's hard to say without knowing the specific configuration in your company.

Update 3

Remove the environment variable "https_proxy" if any or use correct value for "https_proxy"

Xcode 8 shows error that provisioning profile doesn't include signing certificate

You may also solve code signing issues with great Fastlane toolkit. Authors put a lot of effort to effectively automate building, signing iOS apps (and more).

So in the mentioned suite, there is tool sigh which magically resolves any signing issues, hence the name :) Nice thing here is, that this tool encapsulates a knowledge about common signing issues and can detect and resolve most of them.

Fastlane is installed as Ruby gem:

gem install fastlane

And then simply invoked:

fastlane sigh --development

Answer two questions, and voila:

[11:56:55]: No existing profiles found, that match the certificates you have installed locally! Creating a new provisioning profile for you
[11:57:01]: Creating new provisioning profile for 'com.myapp' with name 'com.myapp Development'
[11:57:06]: Downloading provisioning profile...
[11:57:09]: Successfully downloaded provisioning profile...
[11:57:09]: Installing provisioning profile...

Finally, go to Build Settings -> Signing, and switch to newly created provisioning profile, whose name you just saw in the command output.

This example is for development code signing problem (running on the device). Check sigh documentation for all other options.

npm ERR! Error: EPERM: operation not permitted, rename

I closed VS, deleted the node_modules folder.

Then ran:

npm i -D -E [email protected] css- 
[email protected] [email protected] mini-css- 
[email protected] [email protected] [email protected] 
[email protected] [email protected] 

Then had to change the property to not read only on node_modules folder once it got done running.

Then ran:

npm i @microsoft/signalr @types/node

Then opened back up the project in VS and the package.json looked right with the dependencies.

Along the same lines as others talking about read only on node_modules folder and closing down VS to run npm install over.

Angular2 RC5: Can't bind to 'Property X' since it isn't a known property of 'Child Component'

If you use the Angular CLI to create your components, let's say CarComponent, it attaches app to the selector name (i.e app-car) and this throws the above error when you reference the component in the parent view. Therefore you either have to change the selector name in the parent view to let's say <app-car></app-car> or change the selector in the CarComponent to selector: 'car'

Spring Data and Native Query with pagination

You can use below code for h2 and MySQl

    @Query(value = "SELECT req.CREATED_AT createdAt, req.CREATED_BY createdBy,req.APP_ID appId,req.NOTE_ID noteId,req.MODEL model FROM SUMBITED_REQUESTS  req inner join NOTE note where req.NOTE_ID=note.ID and note.CREATED_BY= :userId "
        ,
         countQuery = "SELECT count(*) FROM SUMBITED_REQUESTS req inner join NOTE note WHERE req.NOTE_ID=note.ID and note.CREATED_BY=:userId",
        nativeQuery = true)
Page<UserRequestsDataMapper> getAllRequestForCreator(@Param("userId") String userId,Pageable pageable);

'No database provider has been configured for this DbContext' on SignInManager.PasswordSignInAsync

I could resolve it by overriding Configuration in MyContext through adding connection string to the DbContextOptionsBuilder:

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        if (!optionsBuilder.IsConfigured)
        {
            IConfigurationRoot configuration = new ConfigurationBuilder()
               .SetBasePath(Directory.GetCurrentDirectory())
               .AddJsonFile("appsettings.json")
               .Build();
            var connectionString = configuration.GetConnectionString("DbCoreConnectionString");
            optionsBuilder.UseSqlServer(connectionString);
        }
    }

Trying to pull files from my Github repository: "refusing to merge unrelated histories"

Execute the following command:

git pull origin master --allow-unrelated-histories

A merge vim will open. Add some merging message and:

  1. Press ESC
  2. Press Shift + ';'
  3. Press 'w' and then press 'q'.

And you are good to go.

Listing files in a specific "folder" of a AWS S3 bucket

you can check the type. s3 has a special application/x-directory

bucket.objects({:delimiter=>"/", :prefix=>"f1/"}).each { |obj| p obj.object.content_type }

Angular 2 - Setting selected value on dropdown list

In my case i was returning string value from my api eg: "35" and in my HTML i was using

       <mat-select placeholder="State*" formControlName="states" [(ngModel)]="selectedState" (ngModelChange)="getDistricts()">
            <mat-option *ngFor="let state of formInputs.states" [value]="state.stateId">
              {{ state.stateName }}
            </mat-option>
          </mat-select>

Like others mentioned in the comment value will only accept integer values i guess. So what I did is I converted my string value to integer in my component class like below

          var x = user.state;
          var y: number = +x;

and then assigned it like

  this.EditProfileForm.get('states').setValue(y);

Now the correct values is getting setting by default.

Git refusing to merge unrelated histories on rebase

Since all the other answers are not actually answering the question, here is a solution inspired by this answer on a related question.

So you get your error doing git rebase:

$ git rebase origin/development
fatal: refusing to merge unrelated histories
Error redoing merge 1234deadbeef1234deadbeef

This error doesn't actually cancel the rebase, but you are now in the middle of it:

$ git status
interactive rebase in progress; onto 4321beefdead
Last command done (1 command done):
   pick 1234deadbeef1234deadbeef test merge commit

So you can now do the merge by hand. Find out the parent commits of the original merge commit:

$ git log -1 1234deadbeef1234deadbeef
commit 1234deadbeef1234deadbeef
Merge: 111111111 222222222
Author: Hans Dampf
Date:   Wed Jun 6 18:04:35 2018 +0200

    test merge commit

Find out which of the two merge parents is the one that was merged into the current one (probably the second one, verify with git log 222222222), and then do the merge by hand, copying the commit message of the original merge commit:

$ git merge --allow-unrelated 222222222 --no-commit
Automatic merge went well; stopped before committing as requested
$ git commit -C 1234deadbeef1234deadbeef
[detached HEAD 909af09ec] test merge commit
 Date: Wed Jun 6 18:04:35 2018 +0200
$ git rebase --continue
Successfully rebased and updated refs/heads/test-branch.

Firebase (FCM) how to get token

You can use these 2 methods to get device token with firebase but the second one method is more efficient way..

FirebaseInstallations.getInstance().getToken(false).addOnCompleteListener(new OnCompleteListener<InstallationTokenResult>() {
        @Override
        public void onComplete(@NonNull Task<InstallationTokenResult> task) {
            if(!task.isSuccessful()){
                return;
            }
            // Get new Instance ID token
            DeviceToken = task.getResult().getToken();

        }
    });

Second method : you can also use this one

 FirebaseMessaging.getInstance().getToken().addOnCompleteListener(new OnCompleteListener<String>() {
        @Override
        public void onComplete(@NonNull Task<String> task) {
            DeviceToken= task.getResult();
        }
    });

Chaining Observables in RxJS

About promise composition vs. Rxjs, as this is a frequently asked question, you can refer to a number of previously asked questions on SO, among which :

Basically, flatMap is the equivalent of Promise.then.

For your second question, do you want to replay values already emitted, or do you want to process new values as they arrive? In the first case, check the publishReplay operator. In the second case, standard subscription is enough. However you might need to be aware of the cold. vs. hot dichotomy depending on your source (cf. Hot and Cold observables : are there 'hot' and 'cold' operators? for an illustrated explanation of the concept)

react-router getting this.props.location in child components

(Update) V5.1 & Hooks (Requires React >= 16.8)

You can use useHistory, useLocation and useRouteMatch in your component to get match, history and location .

const Child = () => {
  const location = useLocation();
  const history = useHistory();
  const match = useRouteMatch("write-the-url-you-want-to-match-here");

  return (
    <div>{location.pathname}</div>
  )
}

export default Child

(Update) V4 & V5

You can use withRouter HOC in order to inject match, history and location in your component props.

class Child extends React.Component {
  static propTypes = {
    match: PropTypes.object.isRequired,
    location: PropTypes.object.isRequired,
    history: PropTypes.object.isRequired
  }

  render() {
    const { match, location, history } = this.props

    return (
      <div>{location.pathname}</div>
    )
  }
}

export default withRouter(Child)

(Update) V3

You can use withRouter HOC in order to inject router, params, location, routes in your component props.

class Child extends React.Component {

  render() {
    const { router, params, location, routes } = this.props

    return (
      <div>{location.pathname}</div>
    )
  }
}

export default withRouter(Child)

Original answer

If you don't want to use the props, you can use the context as described in React Router documentation

First, you have to set up your childContextTypes and getChildContext

class App extends React.Component{

  getChildContext() {
    return {
      location: this.props.location
    }
  }

  render() {
    return <Child/>;
  }
}

App.childContextTypes = {
    location: React.PropTypes.object
}

Then, you will be able to access to the location object in your child components using the context like this

class Child extends React.Component{

   render() {
     return (
       <div>{this.context.location.pathname}</div>
     )
   }

}

Child.contextTypes = {
    location: React.PropTypes.object
 }

React.js, wait for setState to finish before triggering a function?

setState() has an optional callback parameter that you can use for this. You only need to change your code slightly, to this:

// Form Input
this.setState(
  {
    originId: input.originId,
    destinationId: input.destinationId,
    radius: input.radius,
    search: input.search
  },
  this.findRoutes         // here is where you put the callback
);

Notice the call to findRoutes is now inside the setState() call, as the second parameter.
Without () because you are passing the function.

Firebase cloud messaging notification not received by device

When you copying your device token, it might copying the space, double check you have copied the correct token

How to solve the memory error in Python

Assuming your example text is representative of all the text, one line would consume about 75 bytes on my machine:

In [3]: sys.getsizeof('usedfor zipper fasten_coat')
Out[3]: 75

Doing some rough math:

75 bytes * 8,000,000 lines / 1024 / 1024 = ~572 MB

So roughly 572 meg to store the strings alone for one of these files. Once you start adding in additional, similarly structured and sized files, you'll quickly approach your virtual address space limits, as mentioned in @ShadowRanger's answer.

If upgrading your python isn't feasible for you, or if it only kicks the can down the road (you have finite physical memory after all), you really have two options: write your results to temporary files in-between loading in and reading the input files, or write your results to a database. Since you need to further post-process the strings after aggregating them, writing to a database would be the superior approach.

Maven:Non-resolvable parent POM and 'parent.relativePath' points at wrong local POM

I'm probably a bit late to the party, but I wrote the junitcategorizer for my thesis project at TOPdesk. Earlier versions indeed used a company internal Parent POM. So your problems are caused by the Parent POM not being resolvable, since it is not available to the outside world.

You can either:

  • Remove the <parent> block, but then have to configure the Surefire, Compiler and other plugins yourself
  • (Only applicable to this specific case!) Change it to point to our Open Source Parent POM by setting:
<parent>
    <groupId>com.topdesk</groupId>
    <artifactId>open-source-parent</artifactId>
    <version>1.2.0</version>
</parent>

Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.12:test (default-test) on project.

3 years already, but the same thing happened to me and I wanted to contribute with my case. Using the @nikk solution I got better results, but other errors still appeared, although yes, I was allowed to package.

However, my task was to implement the code of a co-worker on the server and it did not happen to him in his test environment, so I decided to investigate a little more since the code was functional and did not correspond to me touching anything .

In the end it turned out that his application inserted mysql tables into a database that did not exist. The solution was as easy as creating such a database and the error disappeared.

Disable all Database related auto configuration in Spring Boot

I had the same problem here, solved like this:

Just add another application-{yourprofile}.yml where "yourprofile" could be "client".

In my case I just wanted to remove Redis in a Dev profile, so I added a application-dev.yml next to the main application.yml and it did the job.

In this file I put:

spring.autoconfigure.exclude: org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration,org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration

this should work with properties files as well.

I like the fact that there is no need to change the application code to do that.

What is the difference between json.dump() and json.dumps() in python?

The functions with an s take string parameters. The others take file streams.

Angular2 get clicked element id

There is no need to pass the entire event (unless you need other aspects of the event than you have stated). In fact, it is not recommended. You can pass the element reference with just a little modification.

import {Component} from 'angular2/core';

@Component({
  selector: 'my-app',
  template: `
    <button #btn1 (click)="toggle(btn1)" class="someclass" id="btn1">Button 1</button>
    <button #btn2 (click)="toggle(btn2)" class="someclass" id="btn2">Button 2</button>
  `
})
export class AppComponent {
  buttonValue: string;

  toggle(button) {
    this.buttonValue = button.id;
  }

}

StackBlitz demo

Technically, you don't need to find the button that was clicked, because you have passed the actual element.

Angular guidance

Basic example for sharing text or image with UIActivityViewController in Swift

Share : Text

@IBAction func shareOnlyText(_ sender: UIButton) {
    let text = "This is the text....."
    let textShare = [ text ]
    let activityViewController = UIActivityViewController(activityItems: textShare , applicationActivities: nil)
    activityViewController.popoverPresentationController?.sourceView = self.view 
    self.present(activityViewController, animated: true, completion: nil)
}
}

Share : Image

@IBAction func shareOnlyImage(_ sender: UIButton) {
    let image = UIImage(named: "Product")
    let imageShare = [ image! ]
    let activityViewController = UIActivityViewController(activityItems: imageShare , applicationActivities: nil)
    activityViewController.popoverPresentationController?.sourceView = self.view 
    self.present(activityViewController, animated: true, completion: nil)
 }

Share : Text - Image - URL

   @IBAction func shareAll(_ sender: UIButton) {
    let text = "This is the text...."
    let image = UIImage(named: "Product")
    let myWebsite = NSURL(string:"https://stackoverflow.com/users/4600136/mr-javed-multani?tab=profile")
    let shareAll= [text , image! , myWebsite]
    let activityViewController = UIActivityViewController(activityItems: shareAll, applicationActivities: nil)
    activityViewController.popoverPresentationController?.sourceView = self.view 
    self.present(activityViewController, animated: true, completion: nil)
   }

enter image description here

How to enable production mode?

When ng build command is used it overwrite environment.ts file

By default when ng build command is used it set dev environment

In order to use production environment, use following command ng build --env=prod

This will enable production mode and automatically update environment.ts file

Angular: Cannot find a differ supporting object '[object Object]'

If you don't have an array but you are trying to use your observable like an array even though it's a stream of objects, this won't work natively. I show how to fix this below.

If you are trying to use an observable whose source is of type BehaviorSubject, change it to ReplaySubject then in your component subscribe to it like this:

Component

this.messages$ = this.chatService.messages$.pipe(scan((acc, val) => [...acc, val], []));

Html

<div class="message-list" *ngFor="let item of messages$ | async">

How to change the server port from 3000?

1-> Using File Default Config- Angular-cli comes from the ember-cli project. To run the application on specific port, create an .ember-cli file in the project root. Add your JSON config in there:

{ "port": 1337 }

2->Using Command Line Tool Run this command in Angular-Cli

ng serve --port 1234

To change the port number permanently:

Goto

node_modules/angular-cli/commands/server.js

Search for var defaultPort = process.env.PORT || 4200; (change 4200 to anything else you want).

Disable-web-security in Chrome 48+

In a terminal put these:

cd C:\Program Files (x86)\Google\Chrome\Application

chrome.exe --disable-web-security --user-data-dir="c:/chromedev"

turn typescript object into json string

Just use JSON.stringify(object). It's built into Javascript and can therefore also be used within Typescript.

NPM stuck giving the same error EISDIR: Illegal operation on a directory, read at error (native)

This happened to me on npm publish --access public command. Project contained directory named package.json. This error is sad - because project HAS to have this directory and named exactly package.json (it was part of test case fixture to assert correct behavior of this lib).

Forward X11 failed: Network error: Connection refused

fill in the "X display location" did not work for me. but install MobaXterm did the job.

Why is python setup.py saying invalid command 'bdist_wheel' on Travis CI?

in my case, the version of wheel/pip/setuptools created by venv is too old. this works:

venv/bin/pip  install --upgrade pip wheel setuptools

The program can't start because api-ms-win-crt-runtime-l1-1-0.dll is missing while starting Apache server on my computer

I was facing the same issue. After many tries below solution worked for me.

Before installing VC++ install your windows updates. 1. Go to Start - Control Panel - Windows Update 2. Check for the updates. 3. Install all updates. 4. Restart your system.

After that you can follow the below steps.

@ABHI KUMAR

Download the Visual C++ Redistributable 2015

Visual C++ Redistributable for Visual Studio 2015 (64-bit)

Visual C++ Redistributable for Visual Studio 2015 (32-bit)

(Reinstal if already installed) then restart your computer or use windows updates for download auto.

For link download https://www.microsoft.com/de-de/download/details.aspx?id=48145.

Angular2 http.get() ,map(), subscribe() and observable pattern - basic understanding

import { HttpClientModule } from '@angular/common/http';

The HttpClient API was introduced in the version 4.3.0. It is an evolution of the existing HTTP API and has it's own package @angular/common/http. One of the most notable changes is that now the response object is a JSON by default, so there's no need to parse it with map method anymore .Straight away we can use like below

http.get('friends.json').subscribe(result => this.result =result);

Passing data to components in vue.js

A global JS variable (object) can be used to pass data between components. Example: Passing data from Ammlogin.vue to Options.vue. In Ammlogin.vue rspData is set to the response from the server. In Options.vue the response from the server is made available via rspData.

index.html:

<script>
    var rspData; // global - transfer data between components
</script>

Ammlogin.vue:

....    
export default {
data: function() {return vueData}, 
methods: {
    login: function(event){
        event.preventDefault(); // otherwise the page is submitted...
        vueData.errortxt = "";
        axios.post('http://vueamm...../actions.php', { action: this.$data.action, user: this.$data.user, password: this.$data.password})
            .then(function (response) {
                vueData.user = '';
                vueData.password = '';
                // activate v-link via JS click...
                // JSON.parse is not needed because it is already an object
                if (response.data.result === "ok") {
                    rspData = response.data; // set global rspData
                    document.getElementById("loginid").click();
                } else {
                    vueData.errortxt = "Felaktig avändare eller lösenord!"
                }
            })
            .catch(function (error) {
                // Wu oh! Something went wrong
                vueData.errortxt = error.message;
            });
    },
....

Options.vue:

<template>
<main-layout>
  <p>Alternativ</p>
  <p>Resultat: {{rspData.result}}</p>
  <p>Meddelande: {{rspData.data}}</p>
  <v-link href='/'>Logga ut</v-link>
</main-layout>
</template>
<script>
 import MainLayout from '../layouts/Main.vue'
 import VLink from '../components/VLink.vue'
 var optData = { rspData: rspData}; // rspData is global
 export default {
   data: function() {return optData},
   components: {
     MainLayout,
     VLink
   }
 }
</script>

Android Studio does not show layout preview

Force refresh helped me.

It is at the top of the design tab.

enter image description here

Angular2 Exception: Can't bind to 'routerLink' since it isn't a known native property

For people who find this when attempting to run tests because via npm test or ng test using Karma or whatever else. Your .spec module needs a special router testing import to be able to build.

import { RouterTestingModule } from '@angular/router/testing';

TestBed.configureTestingModule({
    imports: [RouterTestingModule],
    declarations: [AppComponent],
});

http://www.kirjai.com/ng2-component-testing-routerlink-routeroutlet/

How to change indentation in Visual Studio Code?

To change the indentation based on programming language:

  1. Open the Command Palette (CtrlShiftP | macOS: ??P)

  2. Preferences: Configure language specific settings... (command id: workbench.action.configureLanguageBasedSettings)

  3. Select programming language (for example TypeScript)

  4. Add this code:

    "[typescript]": {
        "editor.tabSize": 2
    }
    

See also: VS Code Docs

Error related to only_full_group_by when executing a query in MySql

you can turn off the warning message as explained in the other answers or you can understand what's happening and fix it.

As of MySQL 5.7.5, the default SQL mode includes ONLY_FULL_GROUP_BY which means when you are grouping rows and then selecting something out of that groups, you need to explicitly say which row should that selection be made from. Mysql needs to know which row in the group you're looking for, which gives you two options

Mysql needs to know which row in the group you're looking for, which gives you two options

  • You can also add the column you want to the group statement group by rect.color, rect.value which can be what you want in some cases otherwise would return duplicate results with the same color which you may not want
  • you could also use aggregate functions of mysql to indicate which row you are looking for inside the groups like AVG() MIN() MAX() complete list
  • AND finally you can use ANY_VALUE() if you are sure that all the results inside the group are the same. doc

querySelectorAll with multiple conditions

According to the documentation, just like with any css selector, you can specify as many conditions as you want, and they are treated as logical 'OR'.

This example returns a list of all div elements within the document with a class of either "note" or "alert":

var matches = document.querySelectorAll("div.note, div.alert");

source: https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll

Meanwhile to get the 'AND' functionality you can for example simply use a multiattribute selector, as jquery says:

https://api.jquery.com/multiple-attribute-selector/

ex. "input[id][name$='man']" specifies both id and name of the element and both conditions must be met. For classes it's as obvious as ".class1.class2" to require object of 2 classes.

All possible combinations of both are valid, so you can easily get equivalent of more sophisticated 'OR' and 'AND' expressions.

how to define ssh private key for servers fetched by dynamic inventory in files

The best solution I could find for this problem is to specify private key file in ansible.cfg (I usually keep it in the same folder as a playbook):

[defaults]
inventory=ec2.py
vault_password_file = ~/.vault_pass.txt
host_key_checking = False
private_key_file = /Users/eric/.ssh/secret_key_rsa

Though, it still sets private key globally for all hosts in playbook.

Note: You have to specify full path to the key file - ~user/.ssh/some_key_rsa silently ignored.

Spring Boot - How to log all requests and responses with exceptions in single place?

Currently Spring Boot has the Actuator feature to get the logs of requests and responses.

But you can also get the logs using Aspect(AOP).

Aspect provides you with annotations like: @Before, @AfterReturning, @AfterThrowing etc.

@Before logs the request, @AfterReturning logs the response and @AfterThrowing logs the error message, You may not need all endpoints' log, so you can apply some filters on the packages.

Here are some examples:

For Request:

@Before("within(your.package.where.endpoints.are..*)")
    public void endpointBefore(JoinPoint p) {
        if (log.isTraceEnabled()) {
            log.trace(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " START");
            Object[] signatureArgs = p.getArgs();


            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            try {

                if (signatureArgs[0] != null) {
                    log.trace("\nRequest object: \n" + mapper.writeValueAsString(signatureArgs[0]));
                }
            } catch (JsonProcessingException e) {
            }
        }
    }

Here @Before("within(your.package.where.endpoints.are..*)") has the package path. All endpoints within this package will generate the log.

For Response:

@AfterReturning(value = ("within(your.package.where.endpoints.are..*)"),
            returning = "returnValue")
    public void endpointAfterReturning(JoinPoint p, Object returnValue) {
        if (log.isTraceEnabled()) {
            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            try {
                log.trace("\nResponse object: \n" + mapper.writeValueAsString(returnValue));
            } catch (JsonProcessingException e) {
                System.out.println(e.getMessage());
            }
            log.trace(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " END");
        }
    }

Here @AfterReturning("within(your.package.where.endpoints.are..*)") has the package path. All endpoints within this package will generate the log. Also Object returnValue contains the response.

For Exception:

@AfterThrowing(pointcut = ("within(your.package.where.endpoints.are..*)"), throwing = "e")
public void endpointAfterThrowing(JoinPoint p, Exception e) throws DmoneyException {
    if (log.isTraceEnabled()) {
        System.out.println(e.getMessage());

        e.printStackTrace();


        log.error(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " " + e.getMessage());
    }
}

Here @AfterThrowing(pointcut = ("within(your.package.where.endpoints.are..*)"), throwing = "e") has the package path. All endpoints within this package will generate the log. Also Exception e contains the error response.

Here is the full code:

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import org.apache.log4j.Logger;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

@Aspect
@Order(1)
@Component
@ConditionalOnExpression("${endpoint.aspect.enabled:true}")
public class EndpointAspect {
    static Logger log = Logger.getLogger(EndpointAspect.class);

    @Before("within(your.package.where.is.endpoint..*)")
    public void endpointBefore(JoinPoint p) {
        if (log.isTraceEnabled()) {
            log.trace(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " START");
            Object[] signatureArgs = p.getArgs();


            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            try {

                if (signatureArgs[0] != null) {
                    log.trace("\nRequest object: \n" + mapper.writeValueAsString(signatureArgs[0]));
                }
            } catch (JsonProcessingException e) {
            }
        }
    }

    @AfterReturning(value = ("within(your.package.where.is.endpoint..*)"),
            returning = "returnValue")
    public void endpointAfterReturning(JoinPoint p, Object returnValue) {
        if (log.isTraceEnabled()) {
            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            try {
                log.trace("\nResponse object: \n" + mapper.writeValueAsString(returnValue));
            } catch (JsonProcessingException e) {
                System.out.println(e.getMessage());
            }
            log.trace(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " END");
        }
    }


    @AfterThrowing(pointcut = ("within(your.package.where.is.endpoint..*)"), throwing = "e")
    public void endpointAfterThrowing(JoinPoint p, Exception e) throws Exception {
        if (log.isTraceEnabled()) {
            System.out.println(e.getMessage());

            e.printStackTrace();


            log.error(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " " + e.getMessage());
        }
    }
}

Here, using @ConditionalOnExpression("${endpoint.aspect.enabled:true}") you can enable/disable the log. just add endpoint.aspect.enabled:true into the application.property and control the log

More info about AOP visit here:

Spring docs about AOP

Sample article about AOP

There is no argument given that corresponds to the required formal parameter - .NET Error

I got the same error but it was due to me not creating a default constructor. If you haven't already tried that, create the default constructor like this:

public TestClass() {

}

Best HTTP Authorization header type for JWT

Short answer

The Bearer authentication scheme is what you are looking for.

Long answer

Is it related to bears?

Errr... No :)

According to the Oxford Dictionaries, here's the definition of bearer:

bearer /'b??r?/
noun

  1. A person or thing that carries or holds something.

  2. A person who presents a cheque or other order to pay money.

The first definition includes the following synonyms: messenger, agent, conveyor, emissary, carrier, provider.

And here's the definition of bearer token according to the RFC 6750:

1.2. Terminology

Bearer Token

A security token with the property that any party in possession of the token (a "bearer") can use the token in any way that any other party in possession of it can. Using a bearer token does not require a bearer to prove possession of cryptographic key material (proof-of-possession).

The Bearer authentication scheme is registered in IANA and originally defined in the RFC 6750 for the OAuth 2.0 authorization framework, but nothing stops you from using the Bearer scheme for access tokens in applications that don't use OAuth 2.0.

Stick to the standards as much as you can and don't create your own authentication schemes.


An access token must be sent in the Authorization request header using the Bearer authentication scheme:

2.1. Authorization Request Header Field

When sending the access token in the Authorization request header field defined by HTTP/1.1, the client uses the Bearer authentication scheme to transmit the access token.

For example:

GET /resource HTTP/1.1
Host: server.example.com
Authorization: Bearer mF_9.B5f-4.1JqM

[...]

Clients SHOULD make authenticated requests with a bearer token using the Authorization request header field with the Bearer HTTP authorization scheme. [...]

In case of invalid or missing token, the Bearer scheme should be included in the WWW-Authenticate response header:

3. The WWW-Authenticate Response Header Field

If the protected resource request does not include authentication credentials or does not contain an access token that enables access to the protected resource, the resource server MUST include the HTTP WWW-Authenticate response header field [...].

All challenges defined by this specification MUST use the auth-scheme value Bearer. This scheme MUST be followed by one or more auth-param values. [...].

For example, in response to a protected resource request without authentication:

HTTP/1.1 401 Unauthorized
WWW-Authenticate: Bearer realm="example"

And in response to a protected resource request with an authentication attempt using an expired access token:

HTTP/1.1 401 Unauthorized
WWW-Authenticate: Bearer realm="example",
                         error="invalid_token",
                         error_description="The access token expired"

Invariant Violation: Objects are not valid as a React child

In my case, I added a async to my child function component and encountered this error. Don't use async with child component.

Convert double to float in Java

Converting from double to float will be a narrowing conversion. From the doc:

A narrowing primitive conversion may lose information about the overall magnitude of a numeric value and may also lose precision and range.

A narrowing primitive conversion from double to float is governed by the IEEE 754 rounding rules (§4.2.4). This conversion can lose precision, but also lose range, resulting in a float zero from a nonzero double and a float infinity from a finite double. A double NaN is converted to a float NaN and a double infinity is converted to the same-signed float infinity.

So it is not a good idea. If you still want it you can do it like:

double d = 3.0;
float f = (float) d;

How to add LocalDB to Visual Studio 2015 Community's SQL Server Object Explorer?

  1. Search for sqllocaldb or localDB in your windows start menu and right click on open file location
  2. Open command prompt in the file location you found from the search
  3. On your command prompt type sqllocaldb start

  4. Use <add name="defaultconnection" connectionString="Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=tododb;Integrated Security=True" providerName="System.Data.SqlClient" />

Could not find a part of the path ... bin\roslyn\csc.exe

I have webproject without csproj file and solutions mentiond here did not work for me.

Changing target .NET framework, reinstalling packages (Update-Package -reinstall) and then building the project worked for me. You can even change target framework back after this operation(make suere you reinstall nuget packages again after).

PHP 7 RC3: How to install missing MySQL PDO

I had, pretty much, the same problem. I was able to see that PDO was enabled but I had no available drivers (using PHP 7-RC4). I managed to resolve the issue by adding the php_pdo_mysql extension to those which were enabled.

Hope this helps!

Adding header to all request with Retrofit 2

Try this type header for Retrofit 1.9 and 2.0. For Json Content Type.

@Headers({"Accept: application/json"})
@POST("user/classes")
Call<playlist> addToPlaylist(@Body PlaylistParm parm);

You can add many more headers i.e

@Headers({
        "Accept: application/json",
        "User-Agent: Your-App-Name",
        "Cache-Control: max-age=640000"
    })

Dynamically Add to headers:

@POST("user/classes")
Call<ResponseModel> addToPlaylist(@Header("Content-Type") String content_type, @Body RequestModel req);

Call you method i.e

mAPI.addToPlayList("application/json", playListParam);

Or

Want to pass everytime then Create HttpClient object with http Interceptor:

OkHttpClient httpClient = new OkHttpClient();
        httpClient.networkInterceptors().add(new Interceptor() {
            @Override
            public com.squareup.okhttp.Response intercept(Chain chain) throws IOException {
                Request.Builder requestBuilder = chain.request().newBuilder();
                requestBuilder.header("Content-Type", "application/json");
                return chain.proceed(requestBuilder.build());
            }
        });

Then add to retrofit object

Retrofit retrofit = new Retrofit.Builder().baseUrl(BASE_URL).client(httpClient).build();

UPDATE if you are using Kotlin remove the { } else it will not work

Spring - No EntityManager with actual transaction available for current thread - cannot reliably process 'persist' call

This helped us, maybe it can help others in the future. @Transaction was not working for us, but this did:

@ConditionalOnMissingClass("org.springframework.orm.jpa.JpaTransactionManager")

Change the location of the ~ directory in a Windows install of Git Bash

I know this is an old question, but it is the top google result for "gitbash homedir windows" so figured I'd add my findings.

No matter what I tried I couldn't get git-bash to start in anywhere but my network drive,(U:) in my case making every operation take 15-20 seconds to respond. (Remote employee on VPN, network drive hosted on the other side of the country)

I tried setting HOME and HOMEDIR variables in windows.

I tried setting HOME and HOMEDIR variables in the git installation'setc/profile file.

I tried editing the "Start in" on the git-bash shortcut to be C:/user/myusername.

"env" command inside the git-bash shell would show correct c:/user/myusername. But git-bash would still start in U:

What ultimately fixed it for me was editing the git-bash shortcut and removing the "--cd-to-home" from the Target line.

I'm on Windows 10 running latest version of Git-for-windows 2.22.0.

How to solve ERR_CONNECTION_REFUSED when trying to connect to localhost running IISExpress - Error 502 (Cannot debug from Visual Studio)?

I've solved by going to Project Properties -> Debug, after enable SSL and use the address in your browser

enter image description here

How to install and use "make" in Windows?

  1. Install npm
  2. install Node
  3. Install Make node install make up node install make if above commands displays any error then install Chocolatey(choco) Open cmd and copy and paste the below command (command copied from chocolatey URL) @"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command " [System.Net.ServicePointManager]::SecurityProtocol = 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))" && SET "PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin"

SQL: Two select statements in one query

If you like to keep records separate and not do the union.
Try query below

SELECT (SELECT name,
               games,
               goals
        FROM   tblMadrid
        WHERE  name = 'ronaldo') AS table_a,
       (SELECT name,
               games,
               goals
        FROM   tblBarcelona
        WHERE  name = 'messi')   AS table_b
FROM DUAL

What is the "Upgrade-Insecure-Requests" HTTP header?

This explains the whole thing:

The HTTP Content-Security-Policy (CSP) upgrade-insecure-requests directive instructs user agents to treat all of a site's insecure URLs (those served over HTTP) as though they have been replaced with secure URLs (those served over HTTPS). This directive is intended for web sites with large numbers of insecure legacy URLs that need to be rewritten.

The upgrade-insecure-requests directive is evaluated before block-all-mixed-content and if it is set, the latter is effectively a no-op. It is recommended to set one directive or the other, but not both.

The upgrade-insecure-requests directive will not ensure that users visiting your site via links on third-party sites will be upgraded to HTTPS for the top-level navigation and thus does not replace the Strict-Transport-Security (HSTS) header, which should still be set with an appropriate max-age to ensure that users are not subject to SSL stripping attacks.

Source: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/upgrade-insecure-requests

A better way to check if a path exists or not in PowerShell

Another option is to use IO.FileInfo which gives you so much file info it make life easier just using this type:

PS > mkdir C:\Temp
PS > dir C:\Temp\
PS > [IO.FileInfo] $foo = 'C:\Temp\foo.txt'
PS > $foo.Exists
False
PS > New-TemporaryFile | Move-Item -Destination C:\Temp\foo.txt
PS > $foo.Refresh()
PS > $foo.Exists
True
PS > $foo | Select-Object *


Mode              : -a----
VersionInfo       : File:             C:\Temp\foo.txt
                    InternalName:
                    OriginalFilename:
                    FileVersion:
                    FileDescription:
                    Product:
                    ProductVersion:
                    Debug:            False
                    Patched:          False
                    PreRelease:       False
                    PrivateBuild:     False
                    SpecialBuild:     False
                    Language:

BaseName          : foo
Target            : {}
LinkType          :
Length            : 0
DirectoryName     : C:\Temp
Directory         : C:\Temp
IsReadOnly        : False
FullName          : C:\Temp\foo.txt
Extension         : .txt
Name              : foo.txt
Exists            : True
CreationTime      : 2/27/2019 8:57:33 AM
CreationTimeUtc   : 2/27/2019 1:57:33 PM
LastAccessTime    : 2/27/2019 8:57:33 AM
LastAccessTimeUtc : 2/27/2019 1:57:33 PM
LastWriteTime     : 2/27/2019 8:57:33 AM
LastWriteTimeUtc  : 2/27/2019 1:57:33 PM
Attributes        : Archive

More details on my blog.

What is python's site-packages directory?

site-packages is just the location where Python installs its modules.

No need to "find it", python knows where to find it by itself, this location is always part of the PYTHONPATH (sys.path).

Programmatically you can find it this way:

import sys
site_packages = next(p for p in sys.path if 'site-packages' in p)
print site_packages

'/Users/foo/.envs/env1/lib/python2.7/site-packages'

Lazy Loading vs Eager Loading

Eager Loading When you are sure that want to get multiple entities at a time, for example you have to show user, and user details at the same page, then you should go with eager loading. Eager loading makes single hit on database and load the related entities.

Lazy loading When you have to show users only at the page, and by clicking on users you need to show user details then you need to go with lazy loading. Lazy loading make multiple hits, to get load the related entities when you bind/iterate related entities.

Effect of using sys.path.insert(0, path) and sys.path(append) when loading modules

Because python checks in the directories in sequential order starting at the first directory in sys.path list, till it find the .py file it was looking for.

Ideally, the current directory or the directory of the script is the first always the first element in the list, unless you modify it, like you did. From documentation -

As initialized upon program startup, the first item of this list, path[0], is the directory containing the script that was used to invoke the Python interpreter. If the script directory is not available (e.g. if the interpreter is invoked interactively or if the script is read from standard input), path[0] is the empty string, which directs Python to search modules in the current directory first. Notice that the script directory is inserted before the entries inserted as a result of PYTHONPATH.

So, most probably, you had a .py file with the same name as the module you were trying to import from, in the current directory (where the script was being run from).

Also, a thing to note about ImportErrors , lets say the import error says - ImportError: No module named main - it doesn't mean the main.py is overwritten, no if that was overwritten we would not be having issues trying to read it. Its some module above this that got overwritten with a .py or some other file.

Example -

My directory structure looks like -

 - test
    - shared
         - __init__.py
         - phtest.py
  - testmain.py

Now From testmain.py , I call from shared import phtest , it works fine.

Now lets say I introduce a shared.py in test directory` , example -

 - test
    - shared
         - __init__.py
         - phtest.py
  - testmain.py 
  - shared.py

Now when I try to do from shared import phtest from testmain.py , I will get the error -

ImportError: cannot import name 'phtest'

As you can see above, the file that is causing the issue is shared.py , not phtest.py .

What's the difference between select_related and prefetch_related in Django ORM?

Your understanding is mostly correct. You use select_related when the object that you're going to be selecting is a single object, so OneToOneField or a ForeignKey. You use prefetch_related when you're going to get a "set" of things, so ManyToManyFields as you stated or reverse ForeignKeys. Just to clarify what I mean by "reverse ForeignKeys" here's an example:

class ModelA(models.Model):
    pass

class ModelB(models.Model):
    a = ForeignKey(ModelA)

ModelB.objects.select_related('a').all() # Forward ForeignKey relationship
ModelA.objects.prefetch_related('modelb_set').all() # Reverse ForeignKey relationship

The difference is that select_related does an SQL join and therefore gets the results back as part of the table from the SQL server. prefetch_related on the other hand executes another query and therefore reduces the redundant columns in the original object (ModelA in the above example). You may use prefetch_related for anything that you can use select_related for.

The tradeoffs are that prefetch_related has to create and send a list of IDs to select back to the server, this can take a while. I'm not sure if there's a nice way of doing this in a transaction, but my understanding is that Django always just sends a list and says SELECT ... WHERE pk IN (...,...,...) basically. In this case if the prefetched data is sparse (let's say U.S. State objects linked to people's addresses) this can be very good, however if it's closer to one-to-one, this can waste a lot of communications. If in doubt, try both and see which performs better.

Everything discussed above is basically about the communications with the database. On the Python side however prefetch_related has the extra benefit that a single object is used to represent each object in the database. With select_related duplicate objects will be created in Python for each "parent" object. Since objects in Python have a decent bit of memory overhead this can also be a consideration.

Delay/Wait in a test case of Xcode UI testing

This will create a delay without putting the thread to sleep or throwing an error on timeout:

let delayExpectation = XCTestExpectation()
delayExpectation.isInverted = true
wait(for: [delayExpectation], timeout: 5)

Because the expectation is inverted, it will timeout quietly.

How can I clear the NuGet package cache using the command line?

First, download the NuGet command line tool from here.

Next, open a command prompt and cd to the directory to which nuget.exe was downloaded.

You can list the local caches with this command:

nuget locals all -list

You can clear all caches with this command:

nuget locals all -clear

Reference: https://docs.nuget.org/consume/command-line-reference

What does it mean when the size of a VARCHAR2 in Oracle is declared as 1 byte?

The VARCHAR datatype is synonymous with the VARCHAR2 datatype. To avoid possible changes in behavior, always use the VARCHAR2 datatype to store variable-length character strings.

If your database runs on a single-byte character set (e.g. US7ASCII, WE8MSWIN1252 or WE8ISO8859P1) it does not make any difference whether you use VARCHAR2(x BYTE) or VARCHAR2(x CHAR).

It makes only a difference when your DB runs on multi-byte character set (e.g. AL32UTF8 or AL16UTF16). You can simply see it in this example:

CREATE TABLE my_table (
    VARCHAR2_byte VARCHAR2(1 BYTE), 
    VARCHAR2_char VARCHAR2(1 CHAR)
);

INSERT INTO my_table (VARCHAR2_char) VALUES ('€');
1 row created.

INSERT INTO my_table (VARCHAR2_char) VALUES ('ü');
1 row created.

INSERT INTO my_table (VARCHAR2_byte) VALUES ('€');
INSERT INTO my_table (VARCHAR2_byte) VALUES ('€')
Error at line 10
ORA-12899: value too large for column "MY_TABLE"."VARCHAR2_BYTE" (actual: 3, maximum: 1)

INSERT INTO my_table (VARCHAR2_byte) VALUES ('ü')
Error at line 11
ORA-12899: value too large for column "MY_TABLE"."VARCHAR2_BYTE" (actual: 2, maximum: 1)

VARCHAR2(1 CHAR) means you can store up to 1 character, no matter how many byte it has. In case of Unicode one character may occupy up to 4 bytes.

VARCHAR2(1 BYTE) means you can store a character which occupies max. 1 byte.

If you don't specify either BYTE or CHAR then the default is taken from NLS_LENGTH_SEMANTICS session parameter.

Unless you have Oracle 12c where you can set MAX_STRING_SIZE=EXTENDED the limit is VARCHAR2(4000 CHAR)

However, VARCHAR2(4000 CHAR) does not mean you are guaranteed to store up to 4000 characters. The limit is still 4000 bytes, so in worst case you may store only up to 1000 characters in such field.

See this example ( in UTF-8 occupies 3 bytes):

CREATE TABLE my_table2(VARCHAR2_char VARCHAR2(4000 CHAR));

BEGIN
    INSERT INTO my_table2 VALUES ('€€€€€€€€€€');
    FOR i IN 1..7 LOOP
        UPDATE my_table2 SET VARCHAR2_char = VARCHAR2_char ||VARCHAR2_char;
    END LOOP;
END;
/

SELECT LENGTHB(VARCHAR2_char) , LENGTHC(VARCHAR2_char) FROM my_table2;

LENGTHB(VARCHAR2_CHAR) LENGTHC(VARCHAR2_CHAR)
---------------------- ----------------------
                  3840                   1280
1 row selected.


UPDATE my_table2 SET VARCHAR2_char = VARCHAR2_char ||VARCHAR2_char;

UPDATE my_table2 SET VARCHAR2_char = VARCHAR2_char ||VARCHAR2_char
Error at line 1
ORA-01489: result of string concatenation is too long

See also Examples and limits of BYTE and CHAR semantics usage (NLS_LENGTH_SEMANTICS) (Doc ID 144808.1)

Android Studio is slow (how to speed up)?

Apart from following the optimizations mentioned in existing answers (not much helpful, was still painfully slow), doing below did the trick for me.

HP Notebook with 6 GM RAM and i5 processor I have, still android studio was terribly slow. After checking task manager for memory usage, noticed that there is a software called "HP Touchpoint Analytics Client" that was taking more than 1 GB memory. Found that it's a spyware installed by HP in Windows 10 after searching about it in Google.

Uninstalled a bunch of HP software which does nothing and slows down the system. Now, Android studio is considerably fast - Gradle build completes in less than 30 seconds when compared to more than 2 minutes before. Every keystroke would take 5 seconds to respond, now it is real time and performance is comparable with Eclipse.

This might be true for Laptops from other vendors as well like Dell, etc. HP really messed up the user experience with their spyware for Windows 10 users. Uninstall them, it will help Android studio and improves the overall laptop experience as well.

Hope this helps someone. Thanks.

npm ERR! registry error parsing json - While trying to install Cordova for Ionic Framework in Windows 8

I had this same problem when trying to upgrade pm2 to the latest version.

Thanks to sdm's answer I did npm update npm -g and it did the trick for me.

Why does JSON.parse fail with the empty string?

JSON.parse expects valid notation inside a string, whether that be object {}, array [], string "" or number types (int, float, doubles).

If there is potential for what is parsing to be an empty string then the developer should check for it.

If it was built into the function it would add extra cycles, since built in functions are expected to be extremely performant, it makes sense to not program them for the race case.

How to Merge Two Eloquent Collections?

Merge two different eloquent collections into one and some objects happen to have the same id, one will overwrite the other. Use push() method instead or rethink your approach to the problem to avoid that. Refer to web

Error: " 'dict' object has no attribute 'iteritems' "

I had a similar problem (using 3.5) and lost 1/2 a day to it but here is a something that works - I am retired and just learning Python so I can help my grandson (12) with it.

mydict2={'Atlanta':78,'Macon':85,'Savannah':72}
maxval=(max(mydict2.values()))
print(maxval)
mykey=[key for key,value in mydict2.items()if value==maxval][0]
print(mykey)
YEILDS; 
85
Macon

RecyclerView: Inconsistency detected. Invalid item position

in my case , this solve my issue

rv.setAdapter(null);
rv.setItemAnimator(null);

PS: my problem ocur when i do seache filter in my recyclerview adapter

How to install MinGW-w64 and MSYS2?

MSYS has not been updated a long time, MSYS2 is more active, you can download from MSYS2, it has both mingw and cygwin fork package.

To install the MinGW-w64 toolchain (Reference):

  1. Open MSYS2 shell from start menu
  2. Run pacman -Sy pacman to update the package database
  3. Re-open the shell, run pacman -Syu to update the package database and core system packages
  4. Re-open the shell, run pacman -Su to update the rest
  5. Install compiler:
    • For 32-bit target, run pacman -S mingw-w64-i686-toolchain
    • For 64-bit target, run pacman -S mingw-w64-x86_64-toolchain
  6. Select which package to install, default is all
  7. You may also need make, run pacman -S make

Error - replacement has [x] rows, data has [y]

You could use cut

 df$valueBin <- cut(df$value, c(-Inf, 250, 500, 1000, 2000, Inf), 
    labels=c('<=250', '250-500', '500-1,000', '1,000-2,000', '>2,000'))

data

 set.seed(24)
 df <- data.frame(value= sample(0:2500, 100, replace=TRUE))

Javascript Uncaught TypeError: Cannot read property '0' of undefined

There is no error when I use your code,

but I am calling the hasLetter method like this:

hasLetter("a",words);

How (and why) to use display: table-cell (CSS)

The display:table family of CSS properties is mostly there so that HTML tables can be defined in terms of them. Because they're so intimately linked to a specific tag structure, they don't see much use beyond that.

If you were going to use these properties in your page, you would need a tag structure that closely mimicked that of tables, even though you weren't actually using the <table> family of tags. A minimal version would be a single container element (display:table), with direct children that can all be represented as rows (display:table-row), which themselves have direct children that can all be represented as cells (display:table-cell). There are other properties that let you mimic other tags in the table family, but they require analogous structures in the HTML. Without this, it's going to be very hard (if not impossible) to make good use of these properties.

recyclerview No adapter attached; skipping layout

In Kotlin we had this weird illogical issue.

This didn't work:

 mBinding.serviceProviderCertificates.apply {
            adapter = adapter
            layoutManager =  LinearLayoutManager(activity)
        }

While this worked:

mBinding.serviceProviderCertificates.adapter = adapter
mBinding.serviceProviderCertificates.layoutManager = LinearLayoutManager(activity)

Once I get more after work hours, I will share more insights.

'module' has no attribute 'urlencode'

You use the Python 2 docs but write your program in Python 3.

Hadoop cluster setup - java.net.ConnectException: Connection refused

hduser@marta-komputer:/usr/local/hadoop$ jps

11696 ResourceManager

11842 NodeManager

11171 NameNode

11523 SecondaryNameNode

12167 Jps

Where is your DataNode? Connection refused problem might also be due to no active DataNode. Check datanode logs for issues.

UPDATED:

For this error:

15/03/01 00:59:34 INFO client.RMProxy: Connecting to ResourceManager at /0.0.0.0:8032 java.net.ConnectException: Call From marta-komputer.home/192.168.1.8 to marta-komputer:9000 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused

Add these lines in yarn-site.xml:

<property>
<name>yarn.resourcemanager.address</name>
<value>192.168.1.8:8032</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address</name>
<value>192.168.1.8:8030</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address</name>
<value>192.168.1.8:8031</value>
</property>

Restart the hadoop processes.

Windows CMD command for accessing usb?

Try this batch :

@echo off
Title List of connected external devices by Hackoo
Mode con cols=100 lines=20 & Color 9E
wmic LOGICALDISK where driveType=2 get deviceID > wmic.txt
for /f "skip=1" %%b IN ('type wmic.txt') DO (echo %%b & pause & Dir %%b)
Del wmic.txt
pause

Google Chrome forcing download of "f.txt" file

This issue appears to be causing ongoing consternation, so I will attempt to give a clearer answer than the previously posted answers, which only contain partial hints as to what's happening.

  • Some time around the summer of 2014, IT Security Engineer Michele Spagnuolo (apparently employed at Google Zurich) developed a proof-of-concept exploit and supporting tool called Rosetta Flash that demonstrated a way for hackers to run malicious Flash SWF files from a remote domain in a manner which tricks browsers into thinking it came from the same domain the user was currently browsing. This allows bypassing of the "same-origin policy" and can permit hackers a variety of exploits. You can read the details here: https://miki.it/blog/2014/7/8/abusing-jsonp-with-rosetta-flash/
    • Known affected browsers: Chrome, IE
    • Possibly unaffected browsers: Firefox
  • Adobe has released at least 5 different fixes over the past year while trying to comprehensively fix this vulnerability, but various major websites also introduced their own fixes earlier on in order to prevent mass vulnerability to their userbases. Among the sites to do so: Google, Youtube, Facebook, Github, and others. One component of the ad-hoc mitigation implemented by these website owners was to force the HTTP Header Content-Disposition: attachment; filename=f.txt on the returns from JSONP endpoints. This has the annoyance of causing the browser to automatically download a file called f.txt that you didn't request—but it is far better than your browser automatically running a possibly malicious Flash file.
  • In conclusion, the websites you were visiting when this file spontaneously downloaded are not bad or malicious, but some domain serving content on their pages (usually ads) had content with this exploit inside it. Note that this issue will be random and intermittent in nature because even visiting the same pages consecutively will often produce different ad content. For example, the advertisement domain ad.doubleclick.net probably serves out hundreds of thousands of different ads and only a small percentage likely contain malicious content. This is why various users online are confused thinking they fixed the issue or somehow affected it by uninstalling this program or running that scan, when in fact it is all unrelated. The f.txt download just means you were protected from a recent potential attack with this exploit and you should have no reason to believe you were compromised in any way.
  • The only way I'm aware that you could stop this f.txt file from being downloaded again in the future would be to block the most common domains that appear to be serving this exploit. I've put a short list below of some of the ones implicated in various posts. If you wanted to block these domains from touching your computer, you could add them to your firewall or alternatively you could use the HOSTS file technique described in the second section of this link: http://www.chromefans.org/chrome-tutorial/how-to-block-a-website-in-google-chrome.htm
  • Short list of domains you could block (by no means a comprehensive list). Most of these are highly associated with adware and malware:
    • ad.doubleclick.net
    • adclick.g.doubleclick.net
    • secure-us.imrworldwide.com
    • d.turn.com
    • ad.turn.com
    • secure.insightexpressai.com
    • core.insightexpressai.com

Set session variable in laravel

php artisan make:controller SessionController --plain

Then

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Http\Requests;
use App\Http\Controllers\Controller;

class SessionController extends Controller {
   public function accessSessionData(Request $request) {
      if($request->session()->has('my_name'))
         echo $request->session()->get('my_name');
      else
         echo 'No data in the session';
   }
   public function storeSessionData(Request $request) {
      $request->session()->put('my_name','Ajay kumar');
      echo "Data has been added to session";
   }
   public function deleteSessionData(Request $request) {
      $request->session()->forget('my_name');
      echo "Data has been removed from session.";
   }
}
?>

And all route:

Route::get('session/get','SessionController@accessSessionData');
Route::get('session/set','SessionController@storeSessionData');
Route::get('session/remove','SessionController@deleteSessionData');

More Help: How To Set Session In Laravel?

Mocking a function to raise an Exception to test an except block

Your mock is raising the exception just fine, but the error.resp.status value is missing. Rather than use return_value, just tell Mock that status is an attribute:

barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')

Additional keyword arguments to Mock() are set as attributes on the resulting object.

I put your foo and bar definitions in a my_tests module, added in the HttpError class so I could use it too, and your test then can be ran to success:

>>> from my_tests import foo, HttpError
>>> import mock
>>> with mock.patch('my_tests.bar') as barMock:
...     barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')
...     result = my_test.foo()
... 
404 - 
>>> result is None
True

You can even see the print '404 - %s' % error.message line run, but I think you wanted to use error.content there instead; that's the attribute HttpError() sets from the second argument, at any rate.

How can I parse / create a date time stamp formatted with fractional seconds UTC timezone (ISO 8601, RFC 3339) in Swift?

Based on the acceptable answer in an object paradigm

class ISO8601Format
{
    let format: ISO8601DateFormatter

    init() {
        let format = ISO8601DateFormatter()
        format.formatOptions = [.withInternetDateTime, .withFractionalSeconds]
        format.timeZone = TimeZone(secondsFromGMT: 0)!
        self.format = format
    }

    func date(from string: String) -> Date {
        guard let date = format.date(from: string) else { fatalError() }
        return date
    }

    func string(from date: Date) -> String { return format.string(from: date) }
}


class ISO8601Time
{
    let date: Date
    let format = ISO8601Format() //FIXME: Duplication

    required init(date: Date) { self.date = date }

    convenience init(string: String) {
        let format = ISO8601Format() //FIXME: Duplication
        let date = format.date(from: string)
        self.init(date: date)
    }

    func concise() -> String { return format.string(from: date) }

    func description() -> String { return date.description(with: .current) }
}

callsite

let now = Date()
let time1 = ISO8601Time(date: now)
print("time1.concise(): \(time1.concise())")
print("time1: \(time1.description())")


let time2 = ISO8601Time(string: "2020-03-24T23:16:17.661Z")
print("time2.concise(): \(time2.concise())")
print("time2: \(time2.description())")

How do I debug "Error: spawn ENOENT" on node.js?

In case you're experiencing this issue with an application whose source you cannot modify consider invoking it with the environment variable NODE_DEBUG set to child_process, e.g. NODE_DEBUG=child_process yarn test. This will provide you with information which command lines have been invoked in which directory and usually the last detail is the reason for the failure.

Programmatically Add CenterX/CenterY Constraints

In Swift 5 it looks like this:

label.translatesAutoresizingMaskIntoConstraints = false
label.centerXAnchor.constraint(equalTo: vc.view.centerXAnchor).isActive = true
label.centerYAnchor.constraint(equalTo: vc.view.centerYAnchor).isActive = true

Export a list into a CSV or TXT file in R

cat(capture.output(print(my.list), file="test.txt"))

from R: Export and import a list to .txt file https://stackoverflow.com/users/1855677/42 is the only thing that worked for me. This outputs the list of lists as it is in the text file

How do I make WRAP_CONTENT work on a RecyclerView

You must put a FrameLayout as Main view then put inside a RelativeLayout with ScrollView and at least your RecyclerView, it works for me.

The real trick here is the RelativeLayout...

Happy to help.

Android Studio was unable to find a valid Jvm (Related to MAC OS)

On Mac OS X Yosemite just install:

Java SE Development Kit 8

and

Java Version 8 Update 25

It's all, work for me!

pass JSON to HTTP POST Request

Now with new JavaScript version (ECMAScript 6 http://es6-features.org/#ClassDefinition) there is a better way to submit requests using nodejs and Promise request (http://www.wintellect.com/devcenter/nstieglitz/5-great-features-in-es6-harmony)

Using library: https://github.com/request/request-promise

npm install --save request
npm install --save request-promise

client:

//Sequential execution for node.js using ES6 ECMAScript
var rp = require('request-promise');

rp({
    method: 'POST',
    uri: 'http://localhost:3000/',
    body: {
        val1 : 1,
        val2 : 2
    },
    json: true // Automatically stringifies the body to JSON
}).then(function (parsedBody) {
        console.log(parsedBody);
        // POST succeeded...
    })
    .catch(function (err) {
        console.log(parsedBody);
        // POST failed...
    });

server:

var express = require('express')
    , bodyParser = require('body-parser');

var app = express();

app.use(bodyParser.json());

app.post('/', function(request, response){
    console.log(request.body);      // your JSON

    var jsonRequest = request.body;
    var jsonResponse = {};

    jsonResponse.result = jsonRequest.val1 + jsonRequest.val2;

    response.send(jsonResponse);
});


app.listen(3000);

repository element was not specified in the POM inside distributionManagement element or in -DaltDep loymentRepository=id::layout::url parameter

The issue is fixed by adding repository url under distributionManagement tab in main pom.xml.

Jenkin maven goal : clean deploy -U -Dmaven.test.skip=true

<distributionManagement>
    <repository>
        <id>releases</id>
        <url>http://domain:port/content/repositories/releases</url>
    </repository>
    <snapshotRepository>
        <id>snapshots</id>
        <url>http://domain:port/content/repositories/snapshots</url>
    </snapshotRepository>
</distributionManagement>

RecyclerView inside ScrollView is not working

The new Android Support Library 23.2 solves that problem, you can now set wrap_content as the height of your RecyclerView and works correctly.

Android Support Library 23.2

Efficiently getting all divisors of a given number

for( int i = 1; i * i <= num; i++ )
{
/* upto sqrt is because every divisor after sqrt
    is also found when the number is divided by i.
   EXAMPLE like if number is 90 when it is divided by 5
    then you can also see that 90/5 = 18
    where 18 also divides the number.
   But when number is a perfect square
    then num / i == i therefore only i is the factor
*/

Chrome - ERR_CACHE_MISS

Yes, this is a current issue in Chrome. There is an issue report here.

The fix will appear in 40.x.y.z versions.

Until then? I don't think you can resolve the issue yourself. But you can ignore it. The shown error is only related to the dev tools and does not influence the behavior of your website. If you have any other problems they are not related to this error.

How to replace deprecated android.support.v4.app.ActionBarDrawerToggle

Insted of

drawer.setDrawerListener(toggle);

You can use

drawer.addDrawerListener(toggle);

How to convert entire dataframe to numeric while preserving decimals?

df2 <- data.frame(apply(df1, 2, function(x) as.numeric(as.character(x))))

OperationalError, no such column. Django

Taken from Burhan Khalid's answer and his comment about migrations: what worked for me was removing the content of the "migrations" folder along with the database, and then running manage.py migrate. Removing the database is not enough because of the saved information about table structure in the migrations folder.

How to modify WooCommerce cart, checkout pages (main theme portion)

I've found this works well as a conditional within page.php that includes the WooCommerce cart and checkout screens.

!is_page(array('cart', 'checkout'))

SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Cannot create an automatic instance

An instance might be corrupted or not updated properly.

Try these Commands:

C:\>sqllocaldb stop MSSQLLocalDB
LocalDB instance "MSSQLLocalDB" stopped.
 
C:\>sqllocaldb delete MSSQLLocalDB
LocalDB instance "MSSQLLocalDB" deleted.
 
C:\>sqllocaldb create MSSQLLocalDB
LocalDB instance "MSSQLLocalDB" created with version 13.0.1601.5.
 
C:\>sqllocaldb start MSSQLLocalDB
LocalDB instance "MSSQLLocalDB" started.

How to add constraints programmatically using Swift

the following code works for me in this scenario: an UIImageView forced landscape.

    imagePreview!.isUserInteractionEnabled = true
    imagePreview!.isExclusiveTouch = true
    imagePreview!.contentMode = UIView.ContentMode.scaleAspectFit
    
    // Remove all constraints
    imagePreview!.removeAllConstraints()
    
    // Add the new constraints
    let guide = view.safeAreaLayoutGuide
    imagePreview!.translatesAutoresizingMaskIntoConstraints = false
    imagePreview!.leadingAnchor.constraint(equalTo: guide.leadingAnchor).isActive = true
    imagePreview!.trailingAnchor.constraint(equalTo: guide.trailingAnchor).isActive = true
    imagePreview!.heightAnchor.constraint(equalTo: guide.heightAnchor, multiplier: 1.0).isActive = true

where removeAllConstraints is an extension

extension UIView {
    
    func removeAllConstraints() {
        var _superview = self.superview
        
        func removeAllConstraintsFromView(view: UIView) { for c in view.constraints { view.removeConstraint(c) } }
        
        while let superview = _superview {
            for constraint in superview.constraints {
                
                if let first = constraint.firstItem as? UIView, first == self {
                    superview.removeConstraint(constraint)
                }
                
                if let second = constraint.secondItem as? UIView, second == self {
                    superview.removeConstraint(constraint)
                }
            }
            
            _superview = superview.superview
        }
        
        self.removeConstraints(self.constraints)
        self.translatesAutoresizingMaskIntoConstraints = true
    }
}

SQL Connection Error: System.Data.SqlClient.SqlException (0x80131904)

Check you routes, the update on 9/28/2014 impacted us. We had to adjust our older servers and add new routes. Here is the article http://www.rackspace.com/knowledge_center/article/updating-servicenet-routes-on-cloud-servers-created-before-june-3-2013

How to plot a function curve in R

You mean like this?

> eq = function(x){x*x}
> plot(eq(1:1000), type='l')

Plot of eq over range 1:1000

(Or whatever range of values is relevant to your function)

'NOT NULL constraint failed' after adding to models.py

if the zipcode field is not a required field then add null=True and blank=True, then run makemigrations and migrate command to successfully reflect the changes in the database.

Django 1.7 - "No migrations to apply" when run migrate after makemigrations

This is a very confusing topic. django stores all applied migrations in a table called django_migrations. perform this sql ( i am using postgres . so in query tool section)

select * from django_migrations where app='your appname'  (app in which u have issue with).

This will list all applied migrations for that app.
Go to your app/migration folder and check all migrations . find the migration file associated with your error . file where your table was created or column added or modified.
look for the id of this migration file in django_migrations table( select * from django_migrations where app='your app') .

Then do :

delete from django_migrations where id='id of your migration';

delete multiple id's if you have multiple migrations file associated with your issue.

now reapply migrate

Python manage.py migrate yourappname

second option

  1. Drop tables in your app where you have issue.

  2. delete all migrations for that app from app/migrations folder.(don't delete init.py from that folder).

  3. now run

    python manage.py makemigrations appname

  4. now run

python manage.py migrate appname

Azure SQL Database "DTU percentage" metric

Still not cool enough to comment, but regarding @vladislav's comment the original article was fairly old. Here is an update document regarding DTU's, which would help answer the OP's question.

https://docs.microsoft.com/en-us/azure/sql-database/sql-database-what-is-a-dtu

Error:java: invalid source release: 8 in Intellij. What does it mean?

As Andreas mentioned all about:

Error:java: invalid source release: 8 in IntelliJ
Error:java: invalid source release: 13 in IntelliJ
Error:java: invalid source release: 14 in IntelliJ...

OR whatever version you are using in Java...

The problem will exist if you do not have it matching inside the below code:

<properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
</properties>

This 1.8 in my case, must be matching on your device through MAVEN project library, settings, preferences, project setting and SDK.

Comparing the contents of two files in Sublime Text

The Diff Option only appears if the files are in a folder that is part of a Project.

Than you can actually compare files natively right in Sublime Text.

Navigate to the folder containing them through Open Folder... or in a project Select the two files (ie, by holding Ctrl on Windows or ? on macOS) you want to compare in the sidebar Right click and select the Diff files... option.

CSS flexbox vertically/horizontally center image WITHOUT explicitely defining parent height

Just add the following rules to the parent element:

display: flex;
justify-content: center; /* align horizontal */
align-items: center; /* align vertical */

Here's a sample demo (Resize window to see the image align)

Browser support for Flexbox nowadays is quite good.

For cross-browser compatibility for display: flex and align-items, you can add the older flexbox syntax as well:

display: -webkit-box;
display: -webkit-flex;
display: -moz-box;
display: -ms-flexbox;
display: flex;
-webkit-flex-align: center;
-ms-flex-align: center;
-webkit-align-items: center;
align-items: center;

"Untrusted App Developer" message when installing enterprise iOS Application

If you push it out through MDM it should auto-trust the application (https://support.apple.com/en-gb/HT204460), but it still has to verify the certs etc with Apple to ensure they've not been revoked etc i presume. I had this message preventing the application from launching and it was only when the proxy information was configured so it i could use the internet that it went away after a couple more launch attempts.

How to enable CORS on Firefox?

It's only possible when the server sends this header: Access-Control-Allow-Origin: *

If this is your code then you can setup it like this (PHP):

header('Access-Control-Allow-Origin: *');

SQL Server Service not available in service list after installation of SQL Server Management Studio

You need to start the SQL Server manually. Press

windows + R

type

sqlservermanager12.msc

right click ->Start

Service configuration does not display SQL Server?

Using a PagedList with a ViewModel ASP.Net MVC

I modified the code as follow:

ViewModel

using System.Collections.Generic;
using ContosoUniversity.Models;

namespace ContosoUniversity.ViewModels
{
    public class InstructorIndexData
    {
     public PagedList.IPagedList<Instructor> Instructors { get; set; }
     public PagedList.IPagedList<Course> Courses { get; set; }
     public PagedList.IPagedList<Enrollment> Enrollments { get; set; }
    }
}

Controller

public ActionResult Index(int? id, int? courseID,int? InstructorPage,int? CoursePage,int? EnrollmentPage)
{
 int instructPageNumber = (InstructorPage?? 1);
 int CoursePageNumber = (CoursePage?? 1);
 int EnrollmentPageNumber = (EnrollmentPage?? 1);
 var viewModel = new InstructorIndexData();
 viewModel.Instructors = db.Instructors
    .Include(i => i.OfficeAssignment)
    .Include(i => i.Courses.Select(c => c.Department))
    .OrderBy(i => i.LastName).ToPagedList(instructPageNumber,5);

 if (id != null)
 {
    ViewBag.InstructorID = id.Value;
    viewModel.Courses = viewModel.Instructors.Where(
        i => i.ID == id.Value).Single().Courses.ToPagedList(CoursePageNumber,5);
 }

 if (courseID != null)
 {
    ViewBag.CourseID = courseID.Value;
    viewModel.Enrollments = viewModel.Courses.Where(
        x => x.CourseID == courseID).Single().Enrollments.ToPagedList(EnrollmentPageNumber,5);
 }

 return View(viewModel);
}

View

<div>
   Page @(Model.Instructors.PageCount < Model.Instructors.PageNumber ? 0 : Model.Instructors.PageNumber) of @Model.Instructors.PageCount

   @Html.PagedListPager(Model.Instructors, page => Url.Action("Index", new {InstructorPage=page}))

</div>

I hope this would help you!!

Fill remaining vertical space with CSS using display:flex

A more modern approach would be to use the grid property.

_x000D_
_x000D_
section {_x000D_
  display: grid;_x000D_
  align-items: stretch;_x000D_
  height: 300px;_x000D_
  grid-template-rows: min-content auto 60px;_x000D_
}_x000D_
header {_x000D_
  background: tomato;_x000D_
}_x000D_
div {_x000D_
  background: gold;_x000D_
  overflow: auto;_x000D_
}_x000D_
footer {_x000D_
  background: lightgreen;_x000D_
}
_x000D_
<section>_x000D_
  <header>_x000D_
    header: sized to content_x000D_
    <br>(but is it really?)_x000D_
  </header>_x000D_
  <div>_x000D_
    main content: fills remaining space<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    _x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    _x000D_
  </div>_x000D_
  <footer>_x000D_
    footer: fixed height in px_x000D_
  </footer>_x000D_
</section>
_x000D_
_x000D_
_x000D_

Adding placeholder attribute using Jquery

This line of code might not work in IE 8 because of native support problems.

$(".hidden").attr("placeholder", "Type here to search");

You can try importing a JQuery placeholder plugin for this task. Simply import it to your libraries and initiate from the sample code below.

$('input, textarea').placeholder();

JavaScript Uncaught ReferenceError: jQuery is not defined; Uncaught ReferenceError: $ is not defined

Cause you need to add jQuery library to your file:

jQuery UI is just an addon to jQuery which means that
first you need to include the jQuery library → and then the UI.

<script src="path/to/your/jquery.min.js"></script>
<script src="path/to/your/jquery.ui.min.js"></script>

What's the meaning of "=>" (an arrow formed from equals & greater than) in JavaScript?

Arrow functions which is denoted by symbol (=>) helps you to create anonymous functions and methods. That leads to more shorter syntax. For example, below is a simple “Add” function which returns addition of two numbers.

function Add(num1 , num2 ){
return num1 + num2;
}

The above function becomes shorter by using “Arrow” syntax as shown below.

enter image description here

Above code has two parts as shown in the above diagram: -

Input: — This section specifies the input parameters to the anonymous function.

Logic: — This section comes after the symbol “=>”. This section has the logic of the actual function.

Many developers think that arrow function makes your syntax shorter, simpler and thus makes your code readable.

If you believe the above sentence, then let me assure you it’s a myth. If you think for a moment a properly written function with name is much readable than cryptic functions created in one line using an arrow symbol.

The main use of arrow function is to ensure that code runs in the callers context.

See the below code in which have a global variable "context" defined , this global variable is accessed inside a function "SomeOtherMethod" which is called from other method "SomeMethod".

This "SomeMethod" has local "context" variable. Now because "SomeOtherMethod" is called from ""SomeMethod" we expect it to display "local context" , but it displays "global context".

var context = “global context”;

function SomeOtherMethod(){
alert(this.context);
}

function SomeMethod(){
this.context = “local context”;
SomeOtherMethod();
}

var instance = new SomeMethod();

But if replace the call by using Arrow function it will display "local context".

var context = "global context";

    function SomeMethod(){
        this.context = "local context";
        SomeOtherMethod = () => {
            alert(this.context);
        }
        SomeOtherMethod();
    }
    var instance = new SomeMethod();

I would encourage you to read this link ( Arrow function in JavaScript ) which explain all the scenarios of javascript context and in which scenarios the callers context is not respected.

You can also see the demonstration of Arrow function with javascript in this youtube video which demonstrates practically the term Context.

Could not extract response: no suitable HttpMessageConverter found for response type

As Artem Bilan said, this problem occures because MappingJackson2HttpMessageConverter supports response with application/json content-type only. If you can't change server code, but can change client code(I had such case), you can change content-type header with interceptor:

restTemplate.getInterceptors().add((request, body, execution) -> {
            ClientHttpResponse response = execution.execute(request,body);
            response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
            return response;
        });

Angular directives - when and how to use compile, controller, pre-link and post-link

Controller function

Each directive's controller function is called whenever a new related element is instantiated.

Officially, the controller function is where one:

  • Defines controller logic (methods) that may be shared between controllers.
  • Initiates scope variables.

Again, it is important to remember that if the directive involves an isolated scope, any properties within it that inherit from the parent scope are not yet available.

Do:

  • Define controller logic
  • Initiate scope variables

Do not:

  • Inspect child elements (they may not be rendered yet, bound to scope, etc.).

Add external libraries to CMakeList.txt c++

I would start with upgrade of CMAKE version.

You can use INCLUDE_DIRECTORIES for header location and LINK_DIRECTORIES + TARGET_LINK_LIBRARIES for libraries

INCLUDE_DIRECTORIES(your/header/dir)
LINK_DIRECTORIES(your/library/dir)
rosbuild_add_executable(kinectueye src/kinect_ueye.cpp)
TARGET_LINK_LIBRARIES(kinectueye lib1 lib2 lib2 ...)

note that lib1 is expanded to liblib1.so (on Linux), so use ln to create appropriate links in case you do not have them

SQL - ORDER BY 'datetime' DESC

Try:

SELECT post_datetime 
FROM post 
WHERE type = 'published' 
ORDER BY post_datetime DESC 
LIMIT 3

Bootstrap navbar Active State not working

Add this JavaScript on your main js file.

$(".navbar a").on("click", function(){
      $(".navbar").find(".active").removeClass("active");
      $(this).parent().addClass("active");
    });

Action bar navigation modes are deprecated in Android L

I think a suitable replacement for when you have three to five screens of equal importance is the BottomNavigationActivity,this can be used to switch fragments.

You will notice a wizard exists for this in Android Studio, take care however as Android Studio has a tendency to produce overly complex boiler plate code.

A tutorial can be found here: https://android.jlelse.eu/ultimate-guide-to-bottom-navigation-on-android-75e4efb8105f

Another quality tutorial can be found at Android Hive here: https://www.androidhive.info/2017/12/android-working-with-bottom-navigation/

How to import RecyclerView for Android L-preview

-Go to the DESIGN part in activity_main.xml -In the drag drop pallet select appCompactivity -In appCompactivity Select RecyclerView -On Selection a dialog shall appear click OK -Your project app:gradle will automatically get updated

Remove all constraints affecting a UIView

The only solution I have found so far is to remove the view from its superview:

[view removeFromSuperview]

This looks like it removes all constraints affecting its layout and is ready to be added to a superview and have new constraints attached. However, it will incorrectly remove any subviews from the hierarchy as well, and get rid of [C7] incorrectly.

Django ChoiceField

Better Way to Provide Choice inside a django Model :

from django.db import models

class Student(models.Model):
    FRESHMAN = 'FR'
    SOPHOMORE = 'SO'
    JUNIOR = 'JR'
    SENIOR = 'SR'
    GRADUATE = 'GR'
    YEAR_IN_SCHOOL_CHOICES = [
        (FRESHMAN, 'Freshman'),
        (SOPHOMORE, 'Sophomore'),
        (JUNIOR, 'Junior'),
        (SENIOR, 'Senior'),
        (GRADUATE, 'Graduate'),
    ]
    year_in_school = models.CharField(
        max_length=2,
        choices=YEAR_IN_SCHOOL_CHOICES,
        default=FRESHMAN,
    )

Pandas read_csv low_memory and dtype options

I was facing a similar issue when processing a huge csv file (6 million rows). I had three issues:

  1. the file contained strange characters (fixed using encoding)
  2. the datatype was not specified (fixed using dtype property)
  3. Using the above I still faced an issue which was related with the file_format that could not be defined based on the filename (fixed using try .. except..)
    df = pd.read_csv(csv_file,sep=';', encoding = 'ISO-8859-1',
                     names=['permission','owner_name','group_name','size','ctime','mtime','atime','filename','full_filename'],
                     dtype={'permission':str,'owner_name':str,'group_name':str,'size':str,'ctime':object,'mtime':object,'atime':object,'filename':str,'full_filename':str,'first_date':object,'last_date':object})
    
    try:
        df['file_format'] = [Path(f).suffix[1:] for f in df.filename.tolist()]
    except:
        df['file_format'] = ''

PyCharm import external library

Answer for PyCharm 2016.1 on OSX: (This is an update to the answer by @GeorgeWilliams993's answer above, but I don't have the rep yet to make comments.)

Go to Pycharm menu --> Preferences --> Project: (projectname) --> Project Interpreter

At the top is a popup for "Project Interpreter," and to the right of it is a button with ellipses (...) - click on this button for a different popup and choose "More" (or, as it turns out, click on the main popup and choose "Show All").

This shows a list of interpreters, with one selected. At the bottom of the screen are a set of tools... pick the rightmost one:

Show path for the selected interpreter button

Now you should see all the paths pycharm is searching to find imports, and you can use the "+" button at the bottom to add a new path.

I think the most significant difference from @GeorgeWilliams993's answer is that the gear button has been replaced by a set of ellipses. That threw me off.

Swift Beta performance: sorting arrays

tl;dr Swift 1.0 is now as fast as C by this benchmark using the default release optimisation level [-O].


Here is an in-place quicksort in Swift Beta:

func quicksort_swift(inout a:CInt[], start:Int, end:Int) {
    if (end - start < 2){
        return
    }
    var p = a[start + (end - start)/2]
    var l = start
    var r = end - 1
    while (l <= r){
        if (a[l] < p){
            l += 1
            continue
        }
        if (a[r] > p){
            r -= 1
            continue
        }
        var t = a[l]
        a[l] = a[r]
        a[r] = t
        l += 1
        r -= 1
    }
    quicksort_swift(&a, start, r + 1)
    quicksort_swift(&a, r + 1, end)
}

And the same in C:

void quicksort_c(int *a, int n) {
    if (n < 2)
        return;
    int p = a[n / 2];
    int *l = a;
    int *r = a + n - 1;
    while (l <= r) {
        if (*l < p) {
            l++;
            continue;
        }
        if (*r > p) {
            r--;
            continue;
        }
        int t = *l;
        *l++ = *r;
        *r-- = t;
    }
    quicksort_c(a, r - a + 1);
    quicksort_c(l, a + n - l);
}

Both work:

var a_swift:CInt[] = [0,5,2,8,1234,-1,2]
var a_c:CInt[] = [0,5,2,8,1234,-1,2]

quicksort_swift(&a_swift, 0, a_swift.count)
quicksort_c(&a_c, CInt(a_c.count))

// [-1, 0, 2, 2, 5, 8, 1234]
// [-1, 0, 2, 2, 5, 8, 1234]

Both are called in the same program as written.

var x_swift = CInt[](count: n, repeatedValue: 0)
var x_c = CInt[](count: n, repeatedValue: 0)
for var i = 0; i < n; ++i {
    x_swift[i] = CInt(random())
    x_c[i] = CInt(random())
}

let swift_start:UInt64 = mach_absolute_time();
quicksort_swift(&x_swift, 0, x_swift.count)
let swift_stop:UInt64 = mach_absolute_time();

let c_start:UInt64 = mach_absolute_time();
quicksort_c(&x_c, CInt(x_c.count))
let c_stop:UInt64 = mach_absolute_time();

This converts the absolute times to seconds:

static const uint64_t NANOS_PER_USEC = 1000ULL;
static const uint64_t NANOS_PER_MSEC = 1000ULL * NANOS_PER_USEC;
static const uint64_t NANOS_PER_SEC = 1000ULL * NANOS_PER_MSEC;

mach_timebase_info_data_t timebase_info;

uint64_t abs_to_nanos(uint64_t abs) {
    if ( timebase_info.denom == 0 ) {
        (void)mach_timebase_info(&timebase_info);
    }
    return abs * timebase_info.numer  / timebase_info.denom;
}

double abs_to_seconds(uint64_t abs) {
    return abs_to_nanos(abs) / (double)NANOS_PER_SEC;
}

Here is a summary of the compiler's optimazation levels:

[-Onone] no optimizations, the default for debug.
[-O]     perform optimizations, the default for release.
[-Ofast] perform optimizations and disable runtime overflow checks and runtime type checks.

Time in seconds with [-Onone] for n=10_000:

Swift:            0.895296452
C:                0.001223848

Here is Swift's builtin sort() for n=10_000:

Swift_builtin:    0.77865783

Here is [-O] for n=10_000:

Swift:            0.045478346
C:                0.000784666
Swift_builtin:    0.032513488

As you can see, Swift's performance improved by a factor of 20.

As per mweathers' answer, setting [-Ofast] makes the real difference, resulting in these times for n=10_000:

Swift:            0.000706745
C:                0.000742374
Swift_builtin:    0.000603576

And for n=1_000_000:

Swift:            0.107111846
C:                0.114957179
Swift_sort:       0.092688548

For comparison, this is with [-Onone] for n=1_000_000:

Swift:            142.659763258
C:                0.162065333
Swift_sort:       114.095478272

So Swift with no optimizations was almost 1000x slower than C in this benchmark, at this stage in its development. On the other hand with both compilers set to [-Ofast] Swift actually performed at least as well if not slightly better than C.

It has been pointed out that [-Ofast] changes the semantics of the language, making it potentially unsafe. This is what Apple states in the Xcode 5.0 release notes:

A new optimization level -Ofast, available in LLVM, enables aggressive optimizations. -Ofast relaxes some conservative restrictions, mostly for floating-point operations, that are safe for most code. It can yield significant high-performance wins from the compiler.

They all but advocate it. Whether that's wise or not I couldn't say, but from what I can tell it seems reasonable enough to use [-Ofast] in a release if you're not doing high-precision floating point arithmetic and you're confident no integer or array overflows are possible in your program. If you do need high performance and overflow checks / precise arithmetic then choose another language for now.

BETA 3 UPDATE:

n=10_000 with [-O]:

Swift:            0.019697268
C:                0.000718064
Swift_sort:       0.002094721

Swift in general is a bit faster and it looks like Swift's built-in sort has changed quite significantly.

FINAL UPDATE:

[-Onone]:

Swift:   0.678056695
C:       0.000973914

[-O]:

Swift:   0.001158492
C:       0.001192406

[-Ounchecked]:

Swift:   0.000827764
C:       0.001078914

How to properly validate input values with React.JS?

Use onChange={this.handleChange.bind(this, "name") method and value={this.state.fields["name"]} on input text field and below that create span element to show error, see the below example.

export default class Form extends Component {

  constructor(){
    super()
    this.state ={
       fields: {
         name:'',
         email: '',
         message: ''
       },
       errors: {},
       disabled : false
    }
  }

  handleValidation(){
       let fields = this.state.fields;
       let errors = {};
       let formIsValid = true;

       if(!fields["name"]){
          formIsValid = false;
          errors["name"] = "Name field cannot be empty";
       }

       if(typeof fields["name"] !== "undefined" && !fields["name"] === false){
          if(!fields["name"].match(/^[a-zA-Z]+$/)){
             formIsValid = false;
             errors["name"] = "Only letters";
          }
       }

       if(!fields["email"]){
          formIsValid = false;
          errors["email"] = "Email field cannot be empty";
       }

       if(typeof fields["email"] !== "undefined" && !fields["email"] === false){
          let lastAtPos = fields["email"].lastIndexOf('@');
          let lastDotPos = fields["email"].lastIndexOf('.');

          if (!(lastAtPos < lastDotPos && lastAtPos > 0 && fields["email"].indexOf('@@') === -1 && lastDotPos > 2 && (fields["email"].length - lastDotPos) > 2)) {
             formIsValid = false;
             errors["email"] = "Email is not valid";
           }
      }

      if(!fields["message"]){
         formIsValid = false;
         errors["message"] = " Message field cannot be empty";
      }

      this.setState({errors: errors});
      return formIsValid;
  }

  handleChange(field, e){
      let fields = this.state.fields;
      fields[field] = e.target.value;
      this.setState({fields});
  }

  handleSubmit(e){
      e.preventDefault();
      if(this.handleValidation()){
          console.log('validation successful')
        }else{
          console.log('validation failed')
        }
  }

  render(){
    return (
      <form onSubmit={this.handleSubmit.bind(this)} method="POST">
          <div className="row">
            <div className="col-25">
                <label htmlFor="name">Name</label>
            </div>
            <div className="col-75">
                <input type="text" placeholder="Enter Name"  refs="name" onChange={this.handleChange.bind(this, "name")} value={this.state.fields["name"]}/>
                <span style={{color: "red"}}>{this.state.errors["name"]}</span>
            </div>
          </div>
          <div className="row">
            <div className="col-25">
              <label htmlFor="exampleInputEmail1">Email address</label>
            </div>
            <div className="col-75">
                <input type="email" placeholder="Enter Email" refs="email" aria-describedby="emailHelp" onChange={this.handleChange.bind(this, "email")} value={this.state.fields["email"]}/>
                <span style={{color: "red"}}>{this.state.errors["email"]}</span>
            </div>
          </div>
          <div className="row">
            <div className="col-25">
                <label htmlFor="message">Message</label>
            </div>
            <div className="col-75">
                <textarea type="text" placeholder="Enter Message" rows="5" refs="message" onChange={this.handleChange.bind(this, "message")} value={this.state.fields["message"]}></textarea>
                <span style={{color: "red"}}>{this.state.errors["message"]}</span>
            </div>
          </div>
          <div className="row">
            <button type="submit" disabled={this.state.disabled}>{this.state.disabled ? 'Sending...' : 'Send'}</button>
          </div>
      </form>
    )
  }
}

AngularJS Error: $injector:unpr Unknown Provider

When you are using ui-router, you should not use ng-controller anywhere. Your controllers are automatically instantiated for a ui-view when their appropriate states are activated.

Mipmap drawables for icons

How are these mipmap images different from the other familiar drawable images?

Here is my two cents in trying to explain the difference. There are two cases you deal with when working with images in Android:

  1. You want to load an image for your device density and you are going to use it "as is", without changing its actual size. In this case you should work with drawables and Android will give you the best fitting image.

  2. You want to load an image for your device density, but this image is going to be scaled up or down. For instance this is needed when you want to show a bigger launcher icon, or you have an animation, which increases image's size. In such cases, to ensure best image quality, you should put your image into mipmap folder. What Android will do is, it will try to pick up the image from a higher density bucket instead of scaling it up. This will increase sharpness (quality) of the image.

Thus, the rule of thumb to decide where to put your image into would be:

  • Launcher icons always go into mipmap folder.
  • Images, which are often scaled up (or extremely scaled down) and whose quality is critical for the app, go into mipmap folder as well.
  • All other images are usual drawables.

Laravel Check If Related Model Exists

In php 7.2+ you can't use count on the relation object, so there's no one-fits-all method for all relations. Use query method instead as @tremby provided below:

$model->relation()->exists()

generic solution working on all the relation types (pre php 7.2):

if (count($model->relation))
{
  // exists
}

This will work for every relation since dynamic properties return Model or Collection. Both implement ArrayAccess.

So it goes like this:

single relations: hasOne / belongsTo / morphTo / morphOne

// no related model
$model->relation; // null
count($model->relation); // 0 evaluates to false

// there is one
$model->relation; // Eloquent Model
count($model->relation); // 1 evaluates to true

to-many relations: hasMany / belongsToMany / morphMany / morphToMany / morphedByMany

// no related collection
$model->relation; // Collection with 0 items evaluates to true
count($model->relation); // 0 evaluates to false

// there are related models
$model->relation; // Collection with 1 or more items, evaluates to true as well
count($model->relation); // int > 0 that evaluates to true

Bootstrap 3 dropdown select

If you want to achieve this just keep you dropdown button and style it like the select box. The code is here and below.

.btn {
    cursor: default;
    background-color: #FFF;
    border-radius: 4px;
    text-align: left;
}

.caret {
    position: absolute;
    right: 16px;
    top: 16px;
}

.btn-default:hover, .btn-default:focus, .btn-default:active, .btn-default.active, .open .dropdown-toggle.btn-default {
    background-color: #FFF;    
}

.btn-group.open .dropdown-toggle {
    box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset, 0 0 8px rgba(102, 175, 233, 0.6)
}

.btn-group {width: 100%}
.dropdown-menu {width: 100%;}

To make the button work like a select box, all you need to add is this tiny javascript code:

$('.dropdown-menu a').on('click', function(){    
    $('.dropdown-toggle').html($(this).html() + '<span class="caret"></span>');    
})

If you have multiple custom dropdowns like this you can use this javascript code:

$('.dropdown-menu a').on('click', function(){    
    $(this).parent().parent().prev().html($(this).html() + '<span class="caret"></span>');    
})

How to export database schema in Oracle to a dump file

It depends on which version of Oracle? Older versions require exp (export), newer versions use expdp (data pump); exp was deprecated but still works most of the time.

Before starting, note that Data Pump exports to the server-side Oracle "directory", which is an Oracle symbolic location mapped in the database to a physical location. There may be a default directory (DATA_PUMP_DIR), check by querying DBA_DIRECTORIES:

  SQL> select * from dba_directories;

... and if not, create one

  SQL> create directory DATA_PUMP_DIR as '/oracle/dumps';
  SQL> grant all on directory DATA_PUMP_DIR to myuser;    -- DBAs dont need this grant

Assuming you can connect as the SYSTEM user, or another DBA, you can export any schema like so, to the default directory:

 $ expdp system/manager schemas=user1 dumpfile=user1.dpdmp

Or specifying a specific directory, add directory=<directory name>:

 C:\> expdp system/manager schemas=user1 dumpfile=user1.dpdmp directory=DUMPDIR

With older export utility, you can export to your working directory, and even on a client machine that is remote from the server, using:

 $ exp system/manager owner=user1 file=user1.dmp

Make sure the export is done in the correct charset. If you haven't setup your environment, the Oracle client charset may not match the DB charset, and Oracle will do charset conversion, which may not be what you want. You'll see a warning, if so, then you'll want to repeat the export after setting NLS_LANG environment variable so the client charset matches the database charset. This will cause Oracle to skip charset conversion.

Example for American UTF8 (UNIX):

 $ export NLS_LANG=AMERICAN_AMERICA.AL32UTF8

Windows uses SET, example using Japanese UTF8:

 C:\> set NLS_LANG=Japanese_Japan.AL32UTF8

More info on Data Pump here: http://docs.oracle.com/cd/B28359_01/server.111/b28319/dp_export.htm#g1022624

PLS-00201 - identifier must be declared

When creating the TABLE under B2BOWNER, be sure to prefix the PL/SQL function with the Schema name; i.e. B2BOWNER.F_SSC_Page_Map_Insert.

I did not realize this until the DBAs pointed it out. I could have created the table under my root USER/SCHEMA and the PL/SQL function would have worked fine.

KERNELBASE.dll Exception 0xe0434352 offset 0x000000000000a49d

0xe0434352 is the SEH code for a CLR exception. If you don't understand what that means, stop and read A Crash Course on the Depths of Win32™ Structured Exception Handling. So your process is not handling a CLR exception. Don't shoot the messenger, KERNELBASE.DLL is just the unfortunate victim. The perpetrator is MyApp.exe.

There should be a minidump of the crash in DrWatson folders with a full stack, it will contain everything you need to root cause the issue.

I suggest you wire up, in your myapp.exe code, AppDomain.UnhandledException and Application.ThreadException, as appropriate.

How can I change the width and height of slides on Slick Carousel?

You could also use this:

$('.slider').slick({
   //other settings ................
   respondTo: 'slider', //makes the slider to change width depending on the container it is in
   adaptiveHeight: true //makes the height change depending on the height of the element inside
})

Broken references in Virtualenvs

Simply upgrading python3 worked for me:

brew upgrade python3

Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.

If you have UTF8, use this (actually works with SVG source), like:

btoa(unescape(encodeURIComponent(str)))

example:

 var imgsrc = 'data:image/svg+xml;base64,' + btoa(unescape(encodeURIComponent(markup)));
 var img = new Image(1, 1); // width, height values are optional params 
 img.src = imgsrc;

If you need to decode that base64, use this:

var str2 = decodeURIComponent(escape(window.atob(b64)));
console.log(str2);

Example:

var str = "äöüÄÖÜçéèñ";
var b64 = window.btoa(unescape(encodeURIComponent(str)))
console.log(b64);

var str2 = decodeURIComponent(escape(window.atob(b64)));
console.log(str2);

Note: if you need to get this to work in mobile-safari, you might need to strip all the white-space from the base64 data...

function b64_to_utf8( str ) {
    str = str.replace(/\s/g, '');    
    return decodeURIComponent(escape(window.atob( str )));
}

2017 Update

This problem has been bugging me again.
The simple truth is, atob doesn't really handle UTF8-strings - it's ASCII only.
Also, I wouldn't use bloatware like js-base64.
But webtoolkit does have a small, nice and very maintainable implementation:

/**
*
*  Base64 encode / decode
*  http://www.webtoolkit.info
*
**/
var Base64 = {

    // private property
    _keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="

    // public method for encoding
    , encode: function (input)
    {
        var output = "";
        var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
        var i = 0;

        input = Base64._utf8_encode(input);

        while (i < input.length)
        {
            chr1 = input.charCodeAt(i++);
            chr2 = input.charCodeAt(i++);
            chr3 = input.charCodeAt(i++);

            enc1 = chr1 >> 2;
            enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
            enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
            enc4 = chr3 & 63;

            if (isNaN(chr2))
            {
                enc3 = enc4 = 64;
            }
            else if (isNaN(chr3))
            {
                enc4 = 64;
            }

            output = output +
                this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
                this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
        } // Whend 

        return output;
    } // End Function encode 


    // public method for decoding
    ,decode: function (input)
    {
        var output = "";
        var chr1, chr2, chr3;
        var enc1, enc2, enc3, enc4;
        var i = 0;

        input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
        while (i < input.length)
        {
            enc1 = this._keyStr.indexOf(input.charAt(i++));
            enc2 = this._keyStr.indexOf(input.charAt(i++));
            enc3 = this._keyStr.indexOf(input.charAt(i++));
            enc4 = this._keyStr.indexOf(input.charAt(i++));

            chr1 = (enc1 << 2) | (enc2 >> 4);
            chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
            chr3 = ((enc3 & 3) << 6) | enc4;

            output = output + String.fromCharCode(chr1);

            if (enc3 != 64)
            {
                output = output + String.fromCharCode(chr2);
            }

            if (enc4 != 64)
            {
                output = output + String.fromCharCode(chr3);
            }

        } // Whend 

        output = Base64._utf8_decode(output);

        return output;
    } // End Function decode 


    // private method for UTF-8 encoding
    ,_utf8_encode: function (string)
    {
        var utftext = "";
        string = string.replace(/\r\n/g, "\n");

        for (var n = 0; n < string.length; n++)
        {
            var c = string.charCodeAt(n);

            if (c < 128)
            {
                utftext += String.fromCharCode(c);
            }
            else if ((c > 127) && (c < 2048))
            {
                utftext += String.fromCharCode((c >> 6) | 192);
                utftext += String.fromCharCode((c & 63) | 128);
            }
            else
            {
                utftext += String.fromCharCode((c >> 12) | 224);
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                utftext += String.fromCharCode((c & 63) | 128);
            }

        } // Next n 

        return utftext;
    } // End Function _utf8_encode 

    // private method for UTF-8 decoding
    ,_utf8_decode: function (utftext)
    {
        var string = "";
        var i = 0;
        var c, c1, c2, c3;
        c = c1 = c2 = 0;

        while (i < utftext.length)
        {
            c = utftext.charCodeAt(i);

            if (c < 128)
            {
                string += String.fromCharCode(c);
                i++;
            }
            else if ((c > 191) && (c < 224))
            {
                c2 = utftext.charCodeAt(i + 1);
                string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
                i += 2;
            }
            else
            {
                c2 = utftext.charCodeAt(i + 1);
                c3 = utftext.charCodeAt(i + 2);
                string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                i += 3;
            }

        } // Whend 

        return string;
    } // End Function _utf8_decode 

}

https://www.fileformat.info/info/unicode/utf8.htm

  • For any character equal to or below 127 (hex 0x7F), the UTF-8 representation is one byte. It is just the lowest 7 bits of the full unicode value. This is also the same as the ASCII value.

  • For characters equal to or below 2047 (hex 0x07FF), the UTF-8 representation is spread across two bytes. The first byte will have the two high bits set and the third bit clear (i.e. 0xC2 to 0xDF). The second byte will have the top bit set and the second bit clear (i.e. 0x80 to 0xBF).

  • For all characters equal to or greater than 2048 but less that 65535 (0xFFFF), the UTF-8 representation is spread across three bytes.

Injecting $scope into an angular service function()

You could make your service completely unaware of the scope, but in your controller allow the scope to be updated asynchronously.

The problem you're having is because you're unaware that http calls are made asynchronously, which means you don't get a value immediately as you might. For instance,

var students = $http.get(path).then(function (resp) {
  return resp.data;
}); // then() returns a promise object, not resp.data

There's a simple way to get around this and it's to supply a callback function.

.service('StudentService', [ '$http',
    function ($http) {
    // get some data via the $http
    var path = '/students';

    //save method create a new student if not already exists
    //else update the existing object
    this.save = function (student, doneCallback) {
      $http.post(
        path, 
        {
          params: {
            student: student
          }
        }
      )
      .then(function (resp) {
        doneCallback(resp.data); // when the async http call is done, execute the callback
      });  
    }
.controller('StudentSaveController', ['$scope', 'StudentService', function ($scope, StudentService) {
  $scope.saveUser = function (user) {
    StudentService.save(user, function (data) {
      $scope.message = data; // I'm assuming data is a string error returned from your REST API
    })
  }
}]);

The form:

<div class="form-message">{{message}}</div>

<div ng-controller="StudentSaveController">
  <form novalidate class="simple-form">
    Name: <input type="text" ng-model="user.name" /><br />
    E-mail: <input type="email" ng-model="user.email" /><br />
    Gender: <input type="radio" ng-model="user.gender" value="male" />male
    <input type="radio" ng-model="user.gender" value="female" />female<br />
    <input type="button" ng-click="reset()" value="Reset" />
    <input type="submit" ng-click="saveUser(user)" value="Save" />
  </form>
</div>

This removed some of your business logic for brevity and I haven't actually tested the code, but something like this would work. The main concept is passing a callback from the controller to the service which gets called later in the future. If you're familiar with NodeJS this is the same concept.

Resource interpreted as stylesheet but transferred with MIME type text/html (seems not related with web server)

I came across the same issue whilst resuming work on a old MEAN stack project. I was using nodemon as my local development server and got the same error Resource interpreted as stylesheet but transferred with MIME type text/html. I changed from nodemon to http-server which can be found here. It immediately worked for me.

dyld: Library not loaded: /usr/local/lib/libpng16.16.dylib with anything php related

In my case it was libjpeg. All I had to do was run brew reinstall libjpeg and everything just worked!

python requests file upload

In Ubuntu you can apply this way,

to save file at some location (temporary) and then open and send it to API

      path = default_storage.save('static/tmp/' + f1.name, ContentFile(f1.read()))
      path12 = os.path.join(os.getcwd(), "static/tmp/" + f1.name)
      data={} #can be anything u want to pass along with File
      file1 = open(path12, 'rb')
      header = {"Content-Disposition": "attachment; filename=" + f1.name, "Authorization": "JWT " + token}
       res= requests.post(url,data,header)

How to change font in ipython notebook

Using Jupyterthemes, one can easily change look of notebook.

pip install jupyterthemes

jt -fs 15 

By default code font size is set to 11 . Trying above will change font size. It can be reset using.

jt -r 

This will reset all jupyter theme changes to default.

Change HTML email body font type and size in VBA

I did a little research and was able to write this code:

strbody = "<BODY style=font-size:11pt;font-family:Calibri>Good Morning;<p>We have completed our main aliasing process for today.  All assigned firms are complete.  Please feel free to respond with any questions.<p>Thank you.</BODY>"

apparently by setting the "font-size=11pt" instead of setting the font size <font size=5>, It allows you to select a specific font size like you normally would in a text editor, as opposed to selecting a value from 1-7 like my code was originally.

This link from simpLE MAn gave me some good info.

Google Play Services Missing in Emulator (Android 4.4.2)

Setp 1 : Download the following apk files. 1)com.google.android.gms.apk (https://androidfilehost.com/?fid=95916177934534438) 2)com.android.vending-4.4.22.apk (https://androidfilehost.com/?fid=23203820527945795)

Step 2 : Create a new AVD without the google API's

Step 3 : Run the AVD (Start the emulator)

Step 4 : Install the downloaded apks using adb .

     1)adb install com.google.android.gms-6.7.76_\(1745988-038\)-6776038-minAPI9.apk  
     2)adb install com.android.vending-4.4.22.apk

adb come up with android sdks/studio

Step 5 : Create the application in google developer console

Step 6 : Configure the api key in your Androidmanifest.xml and google api version.

Note : In step1 you need to download the apk based on your Android API level(..18,19,21..) and google play services version (5,5.1,6,6.5......)

This will work 100%.

django - get() returned more than one topic

Get is supposed to return, one and exactly one record, to fix this use filter(), and then take first element of the queryset returned to get the object you were expecting from get, also it would be useful to check if atleast one record is returned before taking out the first element to avoid IndexError

Sharing link on WhatsApp from mobile website (not application) for Android

LATEST UPDATE

Now you can use the latest API from whatsapp https://wa.me/ without worrying about the user agent, the API will do the user agent handling.

Share pre-filled text with contact selection option in respective whatsapp client (Android / iOS / Webapp):

https://wa.me/?text=urlencodedtext

Open Chat Dialog for a particular whatsapp user in respective whatsapp client (Android / iOS / Webapp):

https://wa.me/whatsappphonenumber

Share pre-filled text with a particular user (Combine above two):

https://wa.me/whatsappphonenumber/?text=urlencodedtext

Note : whatsappphonenumber should be full phone number in international format. Omit any zeroes, brackets or dashes when adding the phone number in international format.

For official documentation visit https://faq.whatsapp.com/en/general/26000030

How to convert Django Model object to dict with its fields and values?

Best solution you have ever see.

Convert django.db.models.Model instance and all related ForeignKey, ManyToManyField and @Property function fields into dict.

"""
Convert django.db.models.Model instance and all related ForeignKey, ManyToManyField and @property function fields into dict.
Usage:
    class MyDjangoModel(... PrintableModel):
        to_dict_fields = (...)
        to_dict_exclude = (...)
        ...
    a_dict = [inst.to_dict(fields=..., exclude=...) for inst in MyDjangoModel.objects.all()]
"""
import typing

import django.core.exceptions
import django.db.models
import django.forms.models


def get_decorators_dir(cls, exclude: typing.Optional[set]=None) -> set:
    """
    Ref: https://stackoverflow.com/questions/4930414/how-can-i-introspect-properties-and-model-fields-in-django
    :param exclude: set or None
    :param cls:
    :return: a set of decorators
    """
    default_exclude = {"pk", "objects"}
    if not exclude:
        exclude = default_exclude
    else:
        exclude = exclude.union(default_exclude)

    return set([name for name in dir(cls) if name not in exclude and isinstance(getattr(cls, name), property)])


class PrintableModel(django.db.models.Model):

    class Meta:
        abstract = True

    def __repr__(self):
        return str(self.to_dict())

    def to_dict(self, fields: typing.Optional[typing.Iterable]=None, exclude: typing.Optional[typing.Iterable]=None):
        opts = self._meta
        data = {}

        # support fields filters and excludes
        if not fields:
            fields = set()
        else:
            fields = set(fields)
        default_fields = getattr(self, "to_dict_fields", set())
        fields = fields.union(default_fields)

        if not exclude:
            exclude = set()
        else:
            exclude = set(exclude)
        default_exclude = getattr(self, "to_dict_exclude", set())
        exclude = exclude.union(default_exclude)

        # support syntax "field__childField__..."
        self_fields = set()
        child_fields = dict()
        if fields:
            for i in fields:
                splits = i.split("__")
                if len(splits) == 1:
                    self_fields.add(splits[0])
                else:
                    self_fields.add(splits[0])

                    field_name = splits[0]
                    child_fields.setdefault(field_name, set())
                    child_fields[field_name].add("__".join(splits[1:]))

        self_exclude = set()
        child_exclude = dict()
        if exclude:
            for i in exclude:
                splits = i.split("__")
                if len(splits) == 1:
                    self_exclude.add(splits[0])
                else:
                    field_name = splits[0]
                    if field_name not in child_exclude:
                        child_exclude[field_name] = set()
                    child_exclude[field_name].add("__".join(splits[1:]))

        for f in opts.concrete_fields + opts.many_to_many:
            if self_fields and f.name not in self_fields:
                continue
            if self_exclude and f.name in self_exclude:
                continue

            if isinstance(f, django.db.models.ManyToManyField):
                if self.pk is None:
                    data[f.name] = []
                else:
                    result = []
                    m2m_inst = f.value_from_object(self)
                    for obj in m2m_inst:
                        if isinstance(PrintableModel, obj) and hasattr(obj, "to_dict"):
                            d = obj.to_dict(
                                fields=child_fields.get(f.name),
                                exclude=child_exclude.get(f.name),
                            )
                        else:
                            d = django.forms.models.model_to_dict(
                                obj,
                                fields=child_fields.get(f.name),
                                exclude=child_exclude.get(f.name)
                            )
                        result.append(d)
                    data[f.name] = result
            elif isinstance(f, django.db.models.ForeignKey):
                if self.pk is None:
                    data[f.name] = []
                else:
                    data[f.name] = None
                    try:
                        foreign_inst = getattr(self, f.name)
                    except django.core.exceptions.ObjectDoesNotExist:
                        pass
                    else:
                        if isinstance(foreign_inst, PrintableModel) and hasattr(foreign_inst, "to_dict"):
                            data[f.name] = foreign_inst.to_dict(
                                fields=child_fields.get(f.name),
                                exclude=child_exclude.get(f.name)
                            )
                        elif foreign_inst is not None:
                            data[f.name] = django.forms.models.model_to_dict(
                                foreign_inst,
                                fields=child_fields.get(f.name),
                                exclude=child_exclude.get(f.name),
                            )

            elif isinstance(f, (django.db.models.DateTimeField, django.db.models.DateField)):
                v = f.value_from_object(self)
                if v is not None:
                    data[f.name] = v.isoformat()
                else:
                    data[f.name] = None
            else:
                data[f.name] = f.value_from_object(self)

        # support @property decorator functions
        decorator_names = get_decorators_dir(self.__class__)
        for name in decorator_names:
            if self_fields and name not in self_fields:
                continue
            if self_exclude and name in self_exclude:
                continue

            value = getattr(self, name)
            if isinstance(value, PrintableModel) and hasattr(value, "to_dict"):
                data[name] = value.to_dict(
                    fields=child_fields.get(name),
                    exclude=child_exclude.get(name)
                )
            elif hasattr(value, "_meta"):
                # make sure it is a instance of django.db.models.fields.Field
                data[name] = django.forms.models.model_to_dict(
                    value,
                    fields=child_fields.get(name),
                    exclude=child_exclude.get(name),
                )
            elif isinstance(value, (set, )):
                data[name] = list(value)
            else:
                data[name] = value

        return data

https://gist.github.com/shuge/f543dc2094a3183f69488df2bfb51a52

How to solve the system.data.sqlclient.sqlexception (0x80131904) error

Well, did you DO what the error says? You go to some length telling about installation, but what about the obvious?

  • Check the other server's network configuration in SQL Server.
  • Check the other machines FIREWALL. SQL Server does not open ports automatically, so the windows firewall normally blocks access..

'Invalid update: invalid number of rows in section 0

Here is some code from above added with actual action code (point 1 and 2);

func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
    let deleteAction = UIContextualAction(style: .destructive, title: "Delete") { _, _, completionHandler in

        // 1. remove object from your array
        scannedItems.remove(at: indexPath.row)
        // 2. reload the table, otherwise you get an index out of bounds crash
        self.tableView.reloadData()

        completionHandler(true)
    }
    deleteAction.backgroundColor = .systemOrange
    let configuration = UISwipeActionsConfiguration(actions: [deleteAction])
    configuration.performsFirstActionWithFullSwipe = true
    return configuration
}

converting epoch time with milliseconds to datetime

those are miliseconds, just divide them by 1000, since gmtime expects seconds ...

time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(1236472051807/1000.0))

How to set a variable to be "Today's" date in Python/Pandas

pd.datetime.now().strftime("%d/%m/%Y")

this will give output as '11/02/2019'

you can use add time if you want

pd.datetime.now().strftime("%d/%m/%Y %I:%M:%S")

this will give output as '11/02/2019 11:08:26'

strftime formats

Express.js Response Timeout

There is already a Connect Middleware for Timeout support:

var timeout = express.timeout // express v3 and below
var timeout = require('connect-timeout'); //express v4

app.use(timeout(120000));
app.use(haltOnTimedout);

function haltOnTimedout(req, res, next){
  if (!req.timedout) next();
}

If you plan on using the Timeout middleware as a top-level middleware like above, the haltOnTimedOut middleware needs to be the last middleware defined in the stack and is used for catching the timeout event. Thanks @Aichholzer for the update.

Side Note:

Keep in mind that if you roll your own timeout middleware, 4xx status codes are for client errors and 5xx are for server errors. 408s are reserved for when:

The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time.

Visual Studio breakpoints not being hit

In my case the actual process was different from the original started process.

Usually we bind the local-hosted services through the w3wp.exe process. In my case a custom process was used. Changing to that solved the problem.

One more thing, change from Release to Debug mode. In release mode PDB files are not getting updated with breakpoints details. So make sure you are debugging your application in Debug mode.

nginx: connect() failed (111: Connection refused) while connecting to upstream

I had the same problem when I wrote two upstreams in NGINX conf

upstream php_upstream {
    server unix:/var/run/php/my.site.sock;
    server 127.0.0.1:9000;
}

...

fastcgi_pass php_upstream;

but in /etc/php/7.3/fpm/pool.d/www.conf I listened the socket only

listen = /var/run/php/my.site.sock

So I need just socket, no any 127.0.0.1:9000, and I just removed IP+port upstream

upstream php_upstream {
    server unix:/var/run/php/my.site.sock;
}

This could be rewritten without an upstream

fastcgi_pass unix:/var/run/php/my.site.sock;

The network path was not found

Same problem with me. I solved this by adding @ before connection string (C# has a thing called 'String Literals') like so:

SqlConnection sconnection = new SqlConnection(@"Data Source=(Localdb)\v11.0; Initial Catalog=Mydatabase;Integrated Security=True");

sconnection.Open();

The container 'Maven Dependencies' references non existing library - STS

I'm a little late to the party but I'll give my two cents. I just resolved this issue after spending longer than I'd like on it. The above solutions didn't work for me and here's why:

there was a network issue when maven was downloading the required repositories so I actually didn't have the right jars. adding a -U to a maven clean install went and got them for me. So if the above solutions aren't working try this:

  1. Right click on your project -> Choose Run as -> 5 Maven build...
  2. In the Goals field type "clean install -U" and select Run
  3. After that completes right click on your project again and choose Maven -> Update Project and click ok.

Hope it works for you.

Locking pattern for proper use of .NET MemoryCache

Its a bit late, however... Full implementation:

    [HttpGet]
    public async Task<HttpResponseMessage> GetPageFromUriOrBody(RequestQuery requestQuery)
    {
        log(nameof(GetPageFromUriOrBody), nameof(requestQuery));
        var responseResult = await _requestQueryCache.GetOrCreate(
            nameof(GetPageFromUriOrBody)
            , requestQuery
            , (x) => getPageContent(x).Result);
        return Request.CreateResponse(System.Net.HttpStatusCode.Accepted, responseResult);
    }
    static MemoryCacheWithPolicy<RequestQuery, string> _requestQueryCache = new MemoryCacheWithPolicy<RequestQuery, string>();

Here is getPageContent signature:

async Task<string> getPageContent(RequestQuery requestQuery);

And here is the MemoryCacheWithPolicy implementation:

public class MemoryCacheWithPolicy<TParameter, TResult>
{
    static ILogger _nlogger = new AppLogger().Logger;
    private MemoryCache _cache = new MemoryCache(new MemoryCacheOptions() 
    {
        //Size limit amount: this is actually a memory size limit value!
        SizeLimit = 1024 
    });

    /// <summary>
    /// Gets or creates a new memory cache record for a main data
    /// along with parameter data that is assocciated with main main.
    /// </summary>
    /// <param name="key">Main data cache memory key.</param>
    /// <param name="param">Parameter model that assocciated to main model (request result).</param>
    /// <param name="createCacheData">A delegate to create a new main data to cache.</param>
    /// <returns></returns>
    public async Task<TResult> GetOrCreate(object key, TParameter param, Func<TParameter, TResult> createCacheData)
    {
        // this key is used for param cache memory.
        var paramKey = key + nameof(param);

        if (!_cache.TryGetValue(key, out TResult cacheEntry))
        {
            // key is not in the cache, create data through the delegate.
            cacheEntry = createCacheData(param);
            createMemoryCache(key, cacheEntry, paramKey, param);

            _nlogger.Warn(" cache is created.");
        }
        else
        {
            // data is chached so far..., check if param model is same (or changed)?
            if(!_cache.TryGetValue(paramKey, out TParameter cacheParam))
            {
                //exception: this case should not happened!
            }

            if (!cacheParam.Equals(param))
            {
                // request param is changed, create data through the delegate.
                cacheEntry = createCacheData(param);
                createMemoryCache(key, cacheEntry, paramKey, param);
                _nlogger.Warn(" cache is re-created (param model has been changed).");
            }
            else
            {
                _nlogger.Trace(" cache is used.");
            }

        }
        return await Task.FromResult<TResult>(cacheEntry);
    }
    MemoryCacheEntryOptions createMemoryCacheEntryOptions(TimeSpan slidingOffset, TimeSpan relativeOffset)
    {
        // Cache data within [slidingOffset] seconds, 
        // request new result after [relativeOffset] seconds.
        return new MemoryCacheEntryOptions()

            // Size amount: this is actually an entry count per 
            // key limit value! not an actual memory size value!
            .SetSize(1)

            // Priority on removing when reaching size limit (memory pressure)
            .SetPriority(CacheItemPriority.High)

            // Keep in cache for this amount of time, reset it if accessed.
            .SetSlidingExpiration(slidingOffset)

            // Remove from cache after this time, regardless of sliding expiration
            .SetAbsoluteExpiration(relativeOffset);
        //
    }
    void createMemoryCache(object key, TResult cacheEntry, object paramKey, TParameter param)
    {
        // Cache data within 2 seconds, 
        // request new result after 5 seconds.
        var cacheEntryOptions = createMemoryCacheEntryOptions(
            TimeSpan.FromSeconds(2)
            , TimeSpan.FromSeconds(5));

        // Save data in cache.
        _cache.Set(key, cacheEntry, cacheEntryOptions);

        // Save param in cache.
        _cache.Set(paramKey, param, cacheEntryOptions);
    }
    void checkCacheEntry<T>(object key, string name)
    {
        _cache.TryGetValue(key, out T value);
        _nlogger.Fatal("Key: {0}, Name: {1}, Value: {2}", key, name, value);
    }
}

nlogger is just nLog object to trace MemoryCacheWithPolicy behavior. I re-create the memory cache if request object (RequestQuery requestQuery) is changed through the delegate (Func<TParameter, TResult> createCacheData) or re-create when sliding or absolute time reached their limit. Note that everything is async too ;)

Apache: "AuthType not set!" 500 Error

You can try sudo a2enmod rewrite if you use it in your config.

"The transaction log for database is full due to 'LOG_BACKUP'" in a shared host

Call your hosting company and either have them set up regular log backups or set the recovery model to simple. I'm sure you know what informs the choice, but I'll be explicit anyway. Set the recovery model to full if you need the ability to restore to an arbitrary point in time. Either way the database is misconfigured as is.

Make div scrollable

You need to remove the

min-height:440px;

to

height:440px;

and then add

overflow: auto;

property to the class of the required div

How to rename files and folder in Amazon S3?

This works for renaming the file in the same folder

aws s3  mv s3://bucketname/folder_name1/test_original.csv s3://bucket/folder_name1/test_renamed.csv

Call to getLayoutInflater() in places not in activity

or

View.inflate(context, layout, parent)

disable a hyperlink using jQuery

You can bind a click handler that returns false:

$('.my-link').click(function () {return false;});

To re-enable it again, unbind the handler:

$('.my-link').unbind('click');

Note that disabled doesn't work because it is designed for form inputs only.


jQuery has anticipated this already, providing a shortcut as of jQuery 1.4.3:

$('.my-link').bind('click', false);

And to unbind / re-enable:

$('.my-link').unbind('click', false);

How to find count of Null and Nan values for each column in a PySpark dataframe efficiently?

You can use method shown here and replace isNull with isnan:

from pyspark.sql.functions import isnan, when, count, col

df.select([count(when(isnan(c), c)).alias(c) for c in df.columns]).show()
+-------+----------+---+
|session|timestamp1|id2|
+-------+----------+---+
|      0|         0|  3|
+-------+----------+---+

or

df.select([count(when(isnan(c) | col(c).isNull(), c)).alias(c) for c in df.columns]).show()
+-------+----------+---+
|session|timestamp1|id2|
+-------+----------+---+
|      0|         0|  5|
+-------+----------+---+

How to cut first n and last n columns?

Cut can take several ranges in -f:

Columns up to 4 and from 7 onwards:

cut -f -4,7-

or for fields 1,2,5,6 and from 10 onwards:

cut -f 1,2,5,6,10-

etc

Checking if an object is null in C#

As others have already pointed out, it's not data but rather likely dataList that is null. In addition to that...

catch-throw is an antipattern that almost always makes me want to throw up every time that I see it. Imagine that something goes wrong deep in something that doOtherStuff() calls. All you get back is an Exception object, thrown at the throw in AddData(). No stack trace, no call information, no state, nothing at all to indicate the real source of the problem, unless you go in and switch your debugger to break on exception thrown rather than exception unhandled. If you are catching an exception and just re-throwing it in any way, particularly if the code in the try block is in any way nontrivial, do yourself (and your colleagues, present and future) a favor and throw out the entire try-catch block. Granted, throw; is better than the alternatives, but you are still giving yourself (or whoever else is trying to fix a bug in the code) completely unnecessary headaches. This is not to say that try-catch-throw is necessarily evil per se, as long as you do something relevant with the exception object that was thrown inside the catch block.

Then there's the potential problems of catching Exception in the first place, but that's another matter, particularly since in this particular case you throw an exception.

Another thing that strikes me as more than a little dangerous is that data could potentially change value during the execution of the function, since you are passing by reference. So the null check might pass but before the code gets to doing anything with the value, it's changed - perhaps to null. I'm not positive if this is a concern or not (it might not be), but it seems worth watching out for.

Determine if $.ajax error is a timeout

If your error event handler takes the three arguments (xmlhttprequest, textstatus, and message) when a timeout happens, the status arg will be 'timeout'.

Per the jQuery documentation:

Possible values for the second argument (besides null) are "timeout", "error", "notmodified" and "parsererror".

You can handle your error accordingly then.

I created this fiddle that demonstrates this.

$.ajax({
    url: "/ajax_json_echo/",
    type: "GET",
    dataType: "json",
    timeout: 1000,
    success: function(response) { alert(response); },
    error: function(xmlhttprequest, textstatus, message) {
        if(textstatus==="timeout") {
            alert("got timeout");
        } else {
            alert(textstatus);
        }
    }
});?

With jsFiddle, you can test ajax calls -- it will wait 2 seconds before responding. I put the timeout setting at 1 second, so it should error out and pass back a textstatus of 'timeout' to the error handler.

Hope this helps!

Telnet is not recognized as internal or external command

If your Windows 7 machine is a member of an AD, or if you have UAC enabled, or if security policies are in effect, telnet more often than not must be run as an admin. The easiest way to do this is as follows

  1. Create a shortcut that calls cmd.exe

  2. Go to the shortcut's properties

  3. Click on the Advanced button

  4. Check the "Run as an administrator" checkbox

    After these steps you're all set and telnet should work now.

How to get parameters from a URL string?

In Laravel, I'm use:

private function getValueFromString(string $string, string $key)
{
    parse_str(parse_url($string, PHP_URL_QUERY), $result);

    return isset($result[$key]) ? $result[$key] : null;
}

Detecting EOF in C

Another issue is that you're reading with scanf("%f", &input); only. If the user types something that can't be interpreted as a C floating-point number, like "pi", the scanf() call will not assign anything to input, and won't progress from there. This means it would attempt to keep reading "pi", and failing.

Given the change to while(!feof(stdin)) which other posters are correctly recommending, if you typed "pi" in there would be an endless loop of printing out the former value of input and printing the prompt, but the program would never process any new input.

scanf() returns the number of assignments to input variables it made. If it made no assignment, that means it didn't find a floating-point number, and you should read through more input with something like char string[100];scanf("%99s", string);. This will remove the next string from the input stream (up to 99 characters, anyway - the extra char is for the null terminator on the string).

You know, this is reminding me of all the reasons I hate scanf(), and why I use fgets() instead and then maybe parse it using sscanf().

How do I obtain a list of all schemas in a Sql Server database

Try this query here:

SELECT * FROM sys.schemas

This will give you the name and schema_id for all defines schemas in the database you execute this in.

I don't really know what you mean by querying the "schema API" - these sys. catalog views (in the sys schema) are your best bet for any system information about databases and objects in those databases.

How can I convert a string with dot and comma into a float in Python

What about this?

 my_string = "123,456.908"
 commas_removed = my_string.replace(',', '') # remove comma separation
 my_float = float(commas_removed) # turn from string to float.

In short:

my_float = float(my_string.replace(',', ''))

getElementById in React

You need to have your function in the componentDidMount lifecycle since this is the function that is called when the DOM has loaded.

Make use of refs to access the DOM element

<input type="submit" className="nameInput" id="name" value="cp-dev1" onClick={this.writeData} ref = "cpDev1"/>

  componentDidMount: function(){
    var name = React.findDOMNode(this.refs.cpDev1).value;
    this.someOtherFunction(name);
  }

See this answer for more info on How to access the dom element in React

Changing tab bar item image and text color iOS

I know here are lots of answers but I can't find an easy and valid copy/paste answer for Swift 4.2/ Swift 5.1

tabBarController?.tabBar.tintColor = UIColor.red
tabBarController?.tabBar.unselectedItemTintColor = UIColor.green

Or use UITabBar.appearances() instead of tabBarController?.tabBar like this:

UITabBar.appearances().tintColor = UIColor.red
UITabBar.appearances().unselectedItemTintColor = UIColor.green

Images have to be UIImageRenderingModeAlwaysTemplate

Bootstrap 3 collapsed menu doesn't close on click

This is the code that worked for me:

jQuery('document').ready(function()
{   
   $(".navbar-header button").click(function(event) {
   if ($(".navbar-collapse").hasClass('in'))
   {  $(".navbar-collapse").slideUp();  }
});})

How can I overwrite file contents with new content in PHP?

Use file_put_contents()

file_put_contents('file.txt', 'bar');
echo file_get_contents('file.txt'); // bar
file_put_contents('file.txt', 'foo');
echo file_get_contents('file.txt'); // foo

Alternatively, if you're stuck with fopen() you can use the w or w+ modes:

'w' Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

'w+' Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

How do I change file permissions in Ubuntu

So that you don't mess up other permissions already on the file, use the flag +, such as via

sudo chmod -R o+rw /var/www

Fast way of finding lines in one file that are not in another?

The comm command (short for "common") may be useful comm - compare two sorted files line by line

#find lines only in file1
comm -23 file1 file2 

#find lines only in file2
comm -13 file1 file2 

#find lines common to both files
comm -12 file1 file2 

The man file is actually quite readable for this.

/bin/sh: pushd: not found

here is a method to point

sh -> bash

run this command on terminal

sudo dpkg-reconfigure dash

After this you should see

ls -l /bin/sh

point to /bin/bash (and not to /bin/dash)

Reference

How to include a PHP variable inside a MySQL statement

The text inside $type is substituted directly into the insert string, therefore MySQL gets this:

... VALUES(testing, 'john', 'whatever')

Notice that there are no quotes around testing, you need to put these in like so:

$type = 'testing';
mysql_query("INSERT INTO contents (type, reporter, description) VALUES('$type', 'john', 'whatever')");

I also recommend you read up on SQL injection, as this sort of parameter passing is prone to hacking attempts if you do not sanitize the data being used:

How to cast Object to boolean?

Assuming that yourObject.toString() returns "true" or "false", you can try

boolean b = Boolean.valueOf(yourObject.toString())

Setting an HTML text input box's "default" value. Revert the value when clicking ESC

This esc behavior is IE only by the way. Instead of using jQuery use good old javascript for creating the element and it works.

var element = document.createElement('input');
element.type = 'text';
element.value = 100;
document.getElementsByTagName('body')[0].appendChild(element);

http://jsfiddle.net/gGrf9/

If you want to extend this functionality to other browsers then I would use jQuery's data object to store the default. Then set it when user presses escape.

//store default value for all elements on page. set new default on blur
$('input').each( function() {
    $(this).data('default', $(this).val());
    $(this).blur( function() { $(this).data('default', $(this).val()); });
});

$('input').keyup( function(e) {
    if (e.keyCode == 27) { $(this).val($(this).data('default')); }
});

What are the differences between normal and slim package of jquery?

As noted the Ajax and effects modules have been excluded from jQuery slim the size difference as of 3.3.1 for the minified version unzipped is 85k vs 69k (16k saving for slim) or 30vs24 for zipped, it is important to note that bootstrap 4 uses the slim jQuery so if someone wants the full version they need to call that instead

How do I change the ID of a HTML element with JavaScript?

That seems to work for me:

<html>
<head><style>
#monkey {color:blue}
#ape {color:purple}
</style></head>
<body>
<span id="monkey" onclick="changeid()">
fruit
</span>
<script>
function changeid ()
{
var e = document.getElementById("monkey");
e.id = "ape";
}
</script>
</body>
</html>

The expected behaviour is to change the colour of the word "fruit".

Perhaps your document was not fully loaded when you called the routine?

Rails DateTime.now without Time

Figured it out. This works:

DateTime.now.in_time_zone.midnight

What is the 'pythonic' equivalent to the 'fold' function from functional programming?

Haskell

foldl (+) 0 [1,2,3,4,5]

Python

reduce(lambda a,b: a+b, [1,2,3,4,5], 0)

Obviously, that is a trivial example to illustrate a point. In Python you would just do sum([1,2,3,4,5]) and even Haskell purists would generally prefer sum [1,2,3,4,5].

For non-trivial scenarios when there is no obvious convenience function, the idiomatic pythonic approach is to explicitly write out the for loop and use mutable variable assignment instead of using reduce or a fold.

That is not at all the functional style, but that is the "pythonic" way. Python is not designed for functional purists. See how Python favors exceptions for flow control to see how non-functional idiomatic python is.

no match for ‘operator<<’ in ‘std::operator

Object is a collection of methods and variables.You can't print the variables in object by just cout operation . if you want to show the things inside the object you have to declare either a getter or a display text method in class.

ex

#include <iostream>

using namespace std;

class mystruct

{
private:
    int m_a;
    float m_b;

public:
    mystruct(int x, float y)
    {
            m_a = x;
            m_b = y;
    }
    public:
    void getm_aAndm_b()
    {
        cout<<m_a<<endl;
        cout<<m_b<<endl;
    }



};

int main()
{

    mystruct m = mystruct(5,3.14);

    cout << "my structure " << endl;
    m.getm_aAndm_b();
    return 0;

}

Not that this is just a one way of doing it

How to find out if an item is present in a std::vector?

You can use count too. It will return the number of items present in a vector.

int t=count(vec.begin(),vec.end(),item);

openCV video saving in python

I had the same problem and then I tried this:

frame = cv2.flip(frame,180) 

instead of

frame= cv2.flip(frame,0) 

and it's working.

How to import existing Android project into Eclipse?

Solved: If you want to "Create project from existing source", you need to create a new directory and then put the project directory tree into that new directory. Then point to the new directory when importing.

How to vertically align text in input type="text"?

I found this question while looking for a solution to my own problem. The previous answers rely on padding to make the text appear at the top or bottom of the input or use a combination of height and line-height to align the text to the vertical middle.

Here is an alternative solution to making the text appear in the middle using a div and positioning. Check out the jsfiddle.

<style type="text/css">
    div {
        display: inline-block;
        height: 300px;
        position: relative;
        width: 500px;
    }

    input {
        height: 100%;
        position: absolute;
        text-align: center; /* Optional */
        width: 100%;
    }
</style>

<div>
    <input type="text" value="Hello world!" />
</div>

Python SQLite: database is locked

I also had this problem. I was trying to enter data into the database without saving changes I had made in it. after i saved the changes worked

How to round a numpy array?

Numpy provides two identical methods to do this. Either use

np.round(data, 2)

or

np.around(data, 2)

as they are equivalent.

See the documentation for more information.


Examples:

>>> import numpy as np
>>> a = np.array([0.015, 0.235, 0.112])
>>> np.round(a, 2)
array([0.02, 0.24, 0.11])
>>> np.around(a, 2)
array([0.02, 0.24, 0.11])
>>> np.round(a, 1)
array([0. , 0.2, 0.1])

How to serve static files in Flask

For angular+boilerplate flow which creates next folders tree:

backend/
|
|------ui/
|      |------------------build/          <--'static' folder, constructed by Grunt
|      |--<proj           |----vendors/   <-- angular.js and others here
|      |--     folders>   |----src/       <-- your js
|                         |----index.html <-- your SPA entrypoint 
|------<proj
|------     folders>
|
|------view.py  <-- Flask app here

I use following solution:

...
root = os.path.join(os.path.dirname(os.path.abspath(__file__)), "ui", "build")

@app.route('/<path:path>', methods=['GET'])
def static_proxy(path):
    return send_from_directory(root, path)


@app.route('/', methods=['GET'])
def redirect_to_index():
    return send_from_directory(root, 'index.html')
...

It helps to redefine 'static' folder to custom.

Reading from a text file and storing in a String

How can we read data from a text file and store in a String Variable?

Err, read data from the file and store it in a String variable. It's just code. Not a real question so far.

Is it possible to pass the filename in a method and it would return the String which is the text from the file.

Yes it's possible. It's also a very bad idea. You should deal with the file a part at a time, for example a line at a time. Reading the entire file into memory before you process any of it adds latency; wastes memory; and assumes that the entire file will fit into memory. One day it won't. You don't want to do it this way.

Display an array in a readable/hierarchical format

For single arrays you can use implode, it has a cleaner result to print.

<?php
$msg = array('msg1','msg2','msg3');
echo implode('<br />',$msg);
echo '<br />----------------------<br/>';

echo nl2br(implode("\n",$msg));
echo '<br />----------------------<br/>';
?>

For multidimensional arrays you need to combine with some sort of loop.

<?php
$msgs[] = $msg;
$msgs[] = $msg;
$msgs[] = $msg;
$msgs[] = $msg;
$msgs[] = $msg;
foreach($msgs as $msg) {
    echo implode('<br />',$msg);
    echo '<br />----------------------<br/>';
}
?>

WordPress asking for my FTP credentials to install plugins

On OSX, I used the following, and it worked:

sudo chown -R _www:_www {path to wordpress folder}

_www is the user that PHP runs under on the Mac.

(You may also need to chmod some folders too. I had done that first and it didn't fix it. It wasn't until I did the chown command that it worked, so I'm not sure if it was the chown command alone, or a combination of chmod and chown.)

How to set default value for column of new created table from select statement in 11g

You will need to alter table abc modify (salary default 0);

HTTP 1.0 vs 1.1

Proxy support and the Host field:

HTTP 1.1 has a required Host header by spec.

HTTP 1.0 does not officially require a Host header, but it doesn't hurt to add one, and many applications (proxies) expect to see the Host header regardless of the protocol version.

Example:

GET / HTTP/1.1
Host: www.blahblahblahblah.com

This header is useful because it allows you to route a message through proxy servers, and also because your web server can distinguish between different sites on the same server.

So this means if you have blahblahlbah.com and helohelohelo.com both pointing to the same IP. Your web server can use the Host field to distinguish which site the client machine wants.

Persistent connections:

HTTP 1.1 also allows you to have persistent connections which means that you can have more than one request/response on the same HTTP connection.

In HTTP 1.0 you had to open a new connection for each request/response pair. And after each response the connection would be closed. This lead to some big efficiency problems because of TCP Slow Start.

OPTIONS method:

HTTP/1.1 introduces the OPTIONS method. An HTTP client can use this method to determine the abilities of the HTTP server. It's mostly used for Cross Origin Resource Sharing in web applications.

Caching:

HTTP 1.0 had support for caching via the header: If-Modified-Since.

HTTP 1.1 expands on the caching support a lot by using something called 'entity tag'. If 2 resources are the same, then they will have the same entity tags.

HTTP 1.1 also adds the If-Unmodified-Since, If-Match, If-None-Match conditional headers.

There are also further additions relating to caching like the Cache-Control header.

100 Continue status:

There is a new return code in HTTP/1.1 100 Continue. This is to prevent a client from sending a large request when that client is not even sure if the server can process the request, or is authorized to process the request. In this case the client sends only the headers, and the server will tell the client 100 Continue, go ahead with the body.

Much more:

  • Digest authentication and proxy authentication
  • Extra new status codes
  • Chunked transfer encoding
  • Connection header
  • Enhanced compression support
  • Much much more.

TypeError: 'undefined' is not a function (evaluating '$(document)')

 ;(function($){
        // your code
    })(jQuery);

Place your js code inside the closure above , it should solve the problem.

How to declare array of zeros in python (or an array of a certain size)

You can multiply a list by an integer n to repeat the list n times:

buckets = [0] * 100

Enum Naming Convention - Plural

On the other thread C# naming convention for enum and matching property someone pointed out what I think is a very good idea:

"I know my suggestion goes against the .NET Naming conventions, but I personally prefix enums with 'E' and enum flags with 'F' (similar to how we prefix Interfaces with 'I')."

How to provide user name and password when connecting to a network share

You can either change the thread identity, or P/Invoke WNetAddConnection2. I prefer the latter, as I sometimes need to maintain multiple credentials for different locations. I wrap it into an IDisposable and call WNetCancelConnection2 to remove the creds afterwards (avoiding the multiple usernames error):

using (new NetworkConnection(@"\\server\read", readCredentials))
using (new NetworkConnection(@"\\server2\write", writeCredentials)) {
   File.Copy(@"\\server\read\file", @"\\server2\write\file");
}

Programmatically Hide/Show Android Soft Keyboard

Did you try InputMethodManager.SHOW_IMPLICIT in first window.

and for hiding in second window use InputMethodManager.HIDE_IMPLICIT_ONLY

EDIT :

If its still not working then probably you are putting it at the wrong place. Override onFinishInflate() and show/hide there.

@override
public void onFinishInflate() {
     /* code to show keyboard on startup */
    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.showSoftInput(mUserNameEdit, InputMethodManager.SHOW_IMPLICIT);
}

Using PUT method in HTML form

If you are using nodejs, you can install the package method-override that lets you do this using a middleware. Link to documentation: http://expressjs.com/en/resources/middleware/method-override.html

After installing this, all I had to do was the following:

var methodOverride = require('method-override')
app.use(methodOverride('_method'))

Center Contents of Bootstrap row container

For Bootstrap 4, use the below code:

<div class="mx-auto" style="width: 200px;">
  Centered element
</div>

Ref: https://getbootstrap.com/docs/4.0/utilities/spacing/#horizontal-centering

How to get index of object by its property in JavaScript?

What about this ? :

Data.indexOf(_.find(Data, function(element) {
  return element.name === 'John';
}));

Assuming you are using lodash or underscorejs.

How to check if BigDecimal variable == 0 in java?

A simple and better way for your exemple is:

BigDecimal price;

if(BigDecimal.ZERO.compareTo(price) == 0){
    
   //Returns TRUE

}

jQuery: how to scroll to certain anchor/div on page load?

    /* START --- scroll till anchor */
        (function($) {
             $.fn.goTo = function() {
                  var top_menu_height=$('#div_menu_header').height() + 5 ;
                  //alert ( 'top_menu_height is:' + top_menu_height );
                  $('html, body').animate({
                        scrollTop: (-1)*top_menu_height + $(this).offset().top + 'px'
                  }, 500);
                  return this; // for chaining...
             }
        })(jQuery);

        $(document).ready(function(){

          var url = document.URL, idx = url.indexOf("#") ;
          var hash = idx != -1 ? url.substring(idx+1) : "";

          $(window).load(function(){
             // Remove the # from the hash, as different browsers may or may not include it
             var anchor_to_scroll_to = location.hash.replace('#','');
             if ( anchor_to_scroll_to != '' ) {
                 anchor_to_scroll_to = '#' + anchor_to_scroll_to ;
                 $(anchor_to_scroll_to).goTo();
             }
            });
        });
    /* STOP --- scroll till anchror */

Equivalent of typedef in C#

The best alternative to typedef that I've found in C# is using. For example, I can control float precision via compiler flags with this code:

#if REAL_T_IS_DOUBLE
using real_t = System.Double;
#else
using real_t = System.Single;
#endif

Unfortunately, it requires that you place this at the top of every file where you use real_t. There is currently no way to declare a global namespace type in C#.

How do you merge two Git repositories?

A single branch of another repository can be easily placed under a subdirectory retaining its history. For example:

git subtree add --prefix=rails git://github.com/rails/rails.git master

This will appear as a single commit where all files of Rails master branch are added into "rails" directory. However the commit's title contains a reference to the old history tree:

Add 'rails/' from commit <rev>

Where <rev> is a SHA-1 commit hash. You can still see the history, blame some changes.

git log <rev>
git blame <rev> -- README.md

Note that you can't see the directory prefix from here since this is an actual old branch left intact. You should treat this like a usual file move commit: you will need an extra jump when reaching it.

# finishes with all files added at once commit
git log rails/README.md

# then continue from original tree
git log <rev> -- README.md

There are more complex solutions like doing this manually or rewriting the history as described in other answers.

The git-subtree command is a part of official git-contrib, some packet managers install it by default (OS X Homebrew). But you might have to install it by yourself in addition to git.

HttpGet with HTTPS : SSLPeerUnverifiedException

Your local JVM or remote server may not have the required ciphers. go here

https://www.oracle.com/java/technologies/javase-jce8-downloads.html

and download the zip file that contains: US_export_policy.jar and local_policy.jar

replace the existing files (you need to find the existing path in your JVM).

on a Mac, my path was here. /Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/security

this worked for me.

How to Set Variables in a Laravel Blade Template

I'm going to extend the answer given by @Pim.

Add this to the boot method of your AppServiceProvider

<?php
/*
|--------------------------------------------------------------------------
| Extend blade so we can define a variable
| <code>
| @set(name, value)
| </code>
|--------------------------------------------------------------------------
*/

Blade::directive('set', function($expression) {
    list($name, $val) = explode(',', $expression);
    return "<?php {$name} = {$val}; ?>";
});

This way you don't expose the ability to write any php expression.

You can use this directive like:

@set($var, 10)
@set($var2, 'some string')

How to really read text file from classpath in Java

Somehow the best answer doesn't work for me. I need to use a slightly different code instead.

ClassLoader loader = Thread.currentThread().getContextClassLoader();
InputStream is = loader.getResourceAsStream("SomeTextFile.txt");

I hope this help those who encounters the same issue.

How to solve "Kernel panic - not syncing - Attempted to kill init" -- without erasing any user data

Booting from CD to rescue the installation and editing /etc/selinux/config: changed SELINUX from enforcing to permissive. Rebooted and system booted

/etc/selinux/config before change:

SELINUX=enforcing and SELINUXTYPE=permissive

/etc/selinux/config after change: SELINUX=permissive and SELINUXTYPE=permissive

Array Length in Java

It should be:

int a = arr.length;

Parenthesis should be avoided.

MySQL: Enable LOAD DATA LOCAL INFILE

See below image...

I've added --local-infile=1 to normal mysql command mysql -u root -p

So total line would be :

mysql --local-infile=1 -u root -p

enter image description here

Switch: Multiple values in one case?

You can't specify a range in the case statement, can do as follows.

case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
case 8:
   MessageBox.Show("You are only " + age + " years old\n You must be kidding right.\nPlease fill in your *real* age.");
break;

case 9:
case 10:
case 11:
case 12:
case 13:
case 14:
case 15:
   MessageBox.Show("You are only " + age + " years old\n That's too young!");
   break;

...........etc.

Why isn't .ico file defined when setting window's icon?

This works for me with Python3 on Linux:

import tkinter as tk

# Create Tk window
root = tk.Tk()

# Add icon from GIF file where my GIF is called 'icon.gif' and
# is in the same directory as this .py file
root.tk.call('wm', 'iconphoto', root._w, tk.PhotoImage(file='icon.gif'))

Check string for palindrome

here, checking for the largest palindrome in a string, always starting from 1st char.

public static String largestPalindromeInString(String in) {
    int right = in.length() - 1;
    int left = 0;
    char[] word = in.toCharArray();
    while (right > left && word[right] != word[left]) {
        right--;
    }
    int lenght = right + 1;
    while (right > left && word[right] == word[left]) {

        left++;
        right--;

    }
    if (0 >= right - left) {
        return new String(Arrays.copyOf(word, lenght ));
    } else {
        return largestPalindromeInString(
                new String(Arrays.copyOf(word, in.length() - 1)));
    }
}

How do I add a new class to an element dynamically?

Using CSS only, no. You need to use jQuery to add it.

How can I suppress the newline after a print statement?

Code for Python 3.6.1

print("This first text and " , end="")

print("second text will be on the same line")

print("Unlike this text which will be on a newline")

Output

>>>
This first text and second text will be on the same line
Unlike this text which will be on a newline

Why are interface variables static and final by default?

Since interface doesn't have a direct object, the only way to access them is by using a class/interface and hence that is why if interface variable exists, it should be static otherwise it wont be accessible at all to outside world. Now since it is static, it can hold only one value and any classes that implements it can change it and hence it will be all mess.

Hence if at all there is an interface variable, it will be implicitly static, final and obviously public!!!

Python Requests requests.exceptions.SSLError: [Errno 8] _ssl.c:504: EOF occurred in violation of protocol

To people that can't get above fixes working.

Had to change file ssl.py to fix it. Look for function create_default_context and change line:

context = SSLContext(PROTOCOL_SSLv23)

to

context = SSLContext(PROTOCOL_TLSv1)

Maybe someone can create easier solution without editing ssl.py?

Does Hibernate create tables in the database automatically

If property hibernate.ddl-auto = update, then it will not create the tables automatically. To create tables automatically, you need to set the property to hibernate.ddl-auto = create

The list of option which is used in the spring boot are

  • validate: validate the schema, makes no changes to the database.

  • update: update the schema.

  • create: creates the schema, destroying previous data.

  • create-drop: drop the schema at the end of the session

  • none: is all other cases

So for the first time you can set it to create and then next time on-wards you should set it to update.

nginx 502 bad gateway

The 502 error appears because nginx cannot hand off to php5-cgi. You can try reconfiguring php5-cgi to use unix sockets as opposed to tcp .. then adjust the server config to point to the socket instead of the tcp ...

ps auxww | grep php5-cgi #-- is the process running?  
netstat -an | grep 9000 # is the port open? 

How to move text up using CSS when nothing is working

Your footer container is constricting the width of the inner element with an explicit width on itself, which sees the text clipped at the end and wrapped onto a new line, so change that:

div#fv2-footer-container {
  width: 1090px;
  ...

bower command not found

I am using node version manager. I was getting this error message because I had switched to a different version of node. When I switched back to the version of node where I installed bower, this error went away. In my case, the command was nvm use stable

How to ensure that there is a delay before a service is started in systemd?

You can run the sleep command before your ExecStart with ExecStartPre :

[Service]
ExecStartPre=/bin/sleep 30

Strange Jackson exception being thrown when serializing Hibernate object

I tried @JsonDetect and

@JsonIgnoreProperties(value = { "handler", "hibernateLazyInitializer" })

Neither of them worked for me. Using a third-party module seemed like a lot of work to me. So I just tried making a get call on any property of the lazy object before passing to jackson for serlization. The working code snippet looked something like this :

@RequestMapping(value = "/authenticate", produces = "application/json; charset=utf-8")
    @ResponseBody
    @Transactional
    public Account authenticate(Principal principal) {
        UsernamePasswordAuthenticationToken usernamePasswordAuthenticationToken = (UsernamePasswordAuthenticationToken) principal;
        LoggedInUserDetails loggedInUserDetails = (LoggedInUserDetails) usernamePasswordAuthenticationToken.getPrincipal();
        User user = userRepository.findOne(loggedInUserDetails.getUserId());
        Account account = user.getAccount();
        account.getFullName();      //Since, account is lazy giving it directly to jackson for serlization didn't worked & hence, this quick-fix.
        return account;
    }

Extract XML Value in bash script

I agree with Charles Duffy that a proper XML parser is the right way to go.

But as to what's wrong with your sed command (or did you do it on purpose?).

  • $data was not quoted, so $data is subject to shell's word splitting, filename expansion among other things. One of the consequences being that the spacing in the XML snippet is not preserved.

So given your specific XML structure, this modified sed command should work

title=$(sed -ne '/title/{s/.*<title>\(.*\)<\/title>.*/\1/p;q;}' <<< "$data")

Basically for the line that contains title, extract the text between the tags, then quit (so you don't extract the 2nd <title>)

Change default global installation directory for node.js modules in Windows?

it does not require much configurations just go to advanced system settings copy the path where you have installed your node and just create an environment variable and check with node -v command in your prompt!

Grep characters before and after match?

grep -E -o ".{0,5}test_pattern.{0,5}" test.txt 

This will match up to 5 characters before and after your pattern. The -o switch tells grep to only show the match and -E to use an extended regular expression. Make sure to put the quotes around your expression, else it might be interpreted by the shell.

C# switch statement limitations - why?

I suppose there is no fundamental reason why the compiler couldn't automatically translate your switch statement into:

if (t == typeof(int))
{
...
}
elseif (t == typeof(string))
{
...
}
...

But there isn't much gained by that.

A case statement on integral types allows the compiler to make a number of optimizations:

  1. There is no duplication (unless you duplicate case labels, which the compiler detects). In your example t could match multiple types due to inheritance. Should the first match be executed? All of them?

  2. The compiler can choose to implement a switch statement over an integral type by a jump table to avoid all the comparisons. If you are switching on an enumeration that has integer values 0 to 100 then it creates an array with 100 pointers in it, one for each switch statement. At runtime it simply looks up the address from the array based on the integer value being switched on. This makes for much better runtime performance than performing 100 comparisons.

Missing styles. Is the correct theme chosen for this layout?

This is because you select not a theme of your project. Try to do next:

enter image description here

How to allow download of .json file with ASP.NET

Solution is you need to add json file extension type in MIME Types

Method 1

Go to IIS, Select your application and Find MIME Types

enter image description here

Click on Add from Right panel

File Name Extension = .json

MIME Type = application/json

enter image description here

After adding .json file type in MIME Types, Restart IIS and try to access json file


Method 2

Go to web.config of that application and add this lines in it

 <system.webServer>
   <staticContent>
     <mimeMap fileExtension=".json" mimeType="application/json" />
   </staticContent>
 </system.webServer>

How to use multiprocessing queue in Python?

in "from queue import Queue" there is no module called queue, instead multiprocessing should be used. Therefore, it should look like "from multiprocessing import Queue"

Place cursor at the end of text in EditText

Try this:

EditText et = (EditText)findViewById(R.id.inbox);
et.setSelection(et.getText().length());

How to Execute a Python File in Notepad ++?

First option: (Easiest, recommended)

Open Notepad++. On the menu go to: Run -> Run.. (F5). Type in:

C:\Python26\python.exe "$(FULL_CURRENT_PATH)"

Now, instead of pressing run, press save to create a shortcut for it.

Notes

  • If you have Python 3.1: type in Python31 instead of Python26
  • Add -i if you want the command line window to stay open after the script has finished

Second option

Use a batch script that runs the Python script and then create a shortcut to that from Notepad++.

As explained here: http://it-ride.blogspot.com/2009/08/notepad-and-python.html


Third option: (Not safe)

The code opens “HKEY_CURRENT_USER\Software\Python\PythonCore”, if the key exists it will get the path from the first child key of this key.

Check if this key exists, and if does not, you could try creating it.

Eliminate extra separators below UITableView

Try with this

for Objective C

- (void)viewDidLoad 
 {
  [super viewDidLoad];
  // This will remove extra separators from tableview
  self.yourTableView.tableFooterView = [UIView new];
}

for Swift

override func viewDidLoad() {
 super.viewDidLoad()
 self.yourTableView.tableFooterView = UIView()
}

A circular reference was detected while serializing an object of type 'SubSonic.Schema .DatabaseColumn'.

It seems that there are circular references in your object hierarchy which is not supported by the JSON serializer. Do you need all the columns? You could pick up only the properties you need in the view:

return Json(new 
{  
    PropertyINeed1 = data.PropertyINeed1,
    PropertyINeed2 = data.PropertyINeed2
});

This will make your JSON object lighter and easier to understand. If you have many properties, AutoMapper could be used to automatically map between DTO objects and View objects.

Fetching distinct values on a column using Spark DataFrame

Well to obtain all different values in a Dataframe you can use distinct. As you can see in the documentation that method returns another DataFrame. After that you can create a UDF in order to transform each record.

For example:

val df = sc.parallelize(Array((1, 2), (3, 4), (1, 6))).toDF("age", "salary")

// I obtain all different values. If you show you must see only {1, 3}
val distinctValuesDF = df.select(df("age")).distinct

// Define your udf. In this case I defined a simple function, but they can get complicated.
val myTransformationUDF = udf(value => value / 10)

// Run that transformation "over" your DataFrame
val afterTransformationDF = distinctValuesDF.select(myTransformationUDF(col("age")))

add id to dynamically created <div>

If I got you correctly, it is as easy as

cartDiv.id = "someID";

No need for jQuery.

Have a look at the properties of a DOM Element.

For classes it is the same:

cartDiv.className = "classes here";

But note that this will overwrite already existing class names. If you want to add and remove classes dynamically, you either have to use jQuery or write your own function that does some string replacement.

Fatal error: [] operator not supported for strings

Such behavior is described in Migrating from PHP 7.0.x to PHP 7.1.x/

The empty index operator is not supported for strings anymore Applying the empty index operator to a string (e.g. $str[] = $x) throws a fatal error instead of converting silently to array.

In my case it was a mere initialization. I fixed it by replacing $foo='' with $foo=[].

$foo='';
$foo[]='test';
print_r($foo);

How to select the comparison of two columns as one column in Oracle

select column1, coulumn2, case when colum1=column2 then 'true' else 'false' end from table;

HTH

strcpy() error in Visual studio 2012

Add this line top of the header

#pragma warning(disable : 4996)

How to write a shell script that runs some commands as superuser and some commands not as superuser, without having to babysit it?

If you use this, check man sudo too:

#!/bin/bash

sudo echo "Hi, I'm root"

sudo -u nobody echo "I'm nobody"

sudo -u 1000 touch /test_user

Selenium webdriver click google search

Most of the answers on this page are outdated.
Here's an updated python version to search google and get all results href's:

import urllib.parse
import re
from selenium import webdriver
driver.get("https://google.com/")
q = driver.find_element_by_name('q')
q.send_keys("always look on the bright side of life monty python")
q.submit();
sleep(1)
links= driver.find_elements_by_xpath("//h3[@class='r']//a")
for link in links:
    url = urllib.parse.unquote(webElement.get_attribute("href")) # decode the url
    url = re.sub("^.*?(?:url\?q=)(.*?)&sa.*", r"\1", url, 0, re.IGNORECASE) # get the clean url

Please note that the element id/name/class (@class='r') ** will change depending on the user agent**.
The above code used PhantomJS default user agent.

Hiding the R code in Rmarkdown/knit and just showing the results

Just aggregating the answers and expanding on the basics. Here are three options:

1) Hide Code (individual chunk)

We can include echo=FALSE in the chunk header:

```{r echo=FALSE}
plot(cars)
```

2) Hide Chunks (globally).

We can change the default behaviour of knitr using the knitr::opts_chunk$set function. We call this at the start of the document and include include=FALSE in the chunk header to suppress any output:

---
output: html_document
---

```{r include = FALSE}
knitr::opts_chunk$set(echo=FALSE)
```

```{r}
plot(cars)
```

3) Collapsed Code Chunks

For HTML outputs, we can use code folding to hide the code in the output file. It will still include the code but can only be seen once a user clicks on this. You can read about this further here.

---
output:
  html_document:
    code_folding: "hide"
---


```{r}
plot(cars)
```

enter image description here

TestNG ERROR Cannot find class in classpath

To avoid the error

Cannot find class in classpath: (name of testcase file)

you need to hold Runner class and Test class in one place. I mean src and test folders.

How to change menu item text dynamically in Android

I needed to change the menu icon for the fragment. I altered Charles’s answer to this question a bit for the fragment:

    private Menu top_menu;

    //...
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

       setHasOptionsMenu(true);
       //...
       rootview = inflater.inflate(R.layout.first_content,null);
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        inflater.inflate(R.menu.fragment_menu, menu);
        this.top_menu = menu;
    }


    // my procedure
    private void updateIconMenu() {
         if(top_menu!= null) {
             MenuItem nav_undo = top_menu.findItem(R.id.action_undo);
             nav_undo.setIcon( R.drawable.back);
         }
    }

A method to reverse effect of java String.split()?

There are several examples on DZone Snippets if you want to roll your own that works with a Collection. For example:

public static String join(AbstractCollection<String> s, String delimiter) {
    if (s == null || s.isEmpty()) return "";
    Iterator<String> iter = s.iterator();
    StringBuilder builder = new StringBuilder(iter.next());
    while( iter.hasNext() )
    {
        builder.append(delimiter).append(iter.next());
    }
    return builder.toString();
}

string.IsNullOrEmpty(string) vs. string.IsNullOrWhiteSpace(string)

What about this for a catch all...

if (string.IsNullOrEmpty(x.Trim())
{
}

This will trim all the spaces if they are there avoiding the performance penalty of IsWhiteSpace, which will enable the string to meet the "empty" condition if its not null.

I also think this is clearer and its generally good practise to trim strings anyway especially if you are putting them into a database or something.

Parse an URL in JavaScript

Something like this should work for you. Even if there are multiple query string values then this function should return the value of your desired key.

function getQSValue(url) 
{
    key = 'img_id';
    query_string = url.split('?');
    string_values = query_string[1].split('&');
    for(i=0;  i < string_values.length; i++)
    {
        if( string_values[i].match(key))
            req_value = string_values[i].split('=');    
    }
    return req_value[1];
}

Why call git branch --unset-upstream to fixup?

torek's answer is probably perfect, but I just wanted for the record to mention another case which is different than the one described in the original question but the same error may appear (as it may help others with similar problem):

I have created an empty (new) repo using git init --bare on one of my servers. Then I have git cloned it to a local workspace on my PC.

After committing a single version on the local repo I got that error after calling git status.

Following torek's answer, I understand that what happened is that the first commit on local working directory repo created "master" branch. But on the remote repo (on the server) there was never anything, so there was not even a "master" (remotes/origin/master) branch.

After running git push origin master from local repo the remote repo finally had a master branch. This stopped the error from appearing.

So to conclude - one may get such an error for a fresh new remote repo with zero commits since it has no branch, including "master".

What is the difference between .py and .pyc files?

.pyc contain the compiled bytecode of Python source files. The Python interpreter loads .pyc files before .py files, so if they're present, it can save some time by not having to re-compile the Python source code. You can get rid of them if you want, but they don't cause problems, they're not big, and they may save some time when running programs.

What does #defining WIN32_LEAN_AND_MEAN exclude exactly?

Complementing the above answers and also "Parroting" from the Windows Dev Center documentation,

The Winsock2.h header file internally includes core elements from the Windows.h header file, so there is not usually an #include line for the Windows.h header file in Winsock applications. If an #include line is needed for the Windows.h header file, this should be preceded with the #define WIN32_LEAN_AND_MEAN macro. For historical reasons, the Windows.h header defaults to including the Winsock.h header file for Windows Sockets 1.1. The declarations in the Winsock.h header file will conflict with the declarations in the Winsock2.h header file required by Windows Sockets 2.0. The WIN32_LEAN_AND_MEAN macro prevents the Winsock.h from being included by the Windows.h header ..

How can I schedule a job to run a SQL query daily?

Using T-SQL: My job is executing stored procedure. You can easy change @command to run your sql.

EXEC msdb.dbo.sp_add_job  
   @job_name = N'MakeDailyJob',   
   @enabled = 1,   
   @description = N'Procedure execution every day' ; 

 EXEC msdb.dbo.sp_add_jobstep  
    @job_name = N'MakeDailyJob',   
    @step_name = N'Run Procedure',   
    @subsystem = N'TSQL',   
    @command = 'exec BackupFromConfig';

 EXEC msdb.dbo.sp_add_schedule  
    @schedule_name = N'Everyday schedule',   
    @freq_type = 4,  -- daily start
    @freq_interval = 1,
    @active_start_time = '230000' ;   -- start time 23:00:00

 EXEC msdb.dbo.sp_attach_schedule  
   @job_name = N'MakeDailyJob',  
   @schedule_name = N'Everyday schedule' ;

 EXEC msdb.dbo.sp_add_jobserver  
   @job_name = N'MakeDailyJob',  
   @server_name = @@servername ;

python global name 'self' is not defined

It should be something like:

class Person:
   def setavalue(self, name):         
      self.myname = name      
   def printaname(self):         
      print "Name", self.myname           

def main():
   p = Person()
   p.setavalue("harry")
   p.printaname()  

How can I use JavaScript in Java?

Rhino is what you are looking for.

Rhino is an open-source implementation of JavaScript written entirely in Java. It is typically embedded into Java applications to provide scripting to end users.

Update: Now Nashorn, which is more performant JavaScript Engine for Java, is available with jdk8.

Getting the 'external' IP address in Java

The truth is: 'you can't' in the sense that you posed the question. NAT happens outside of the protocol. There is no way for your machine's kernel to know how your NAT box is mapping from external to internal IP addresses. Other answers here offer tricks involving methods of talking to outside web sites.

Why is Tkinter Entry's get function returning nothing?

A simple example without classes:

from tkinter import *    
master = Tk()

# Create this method before you create the entry
def return_entry(en):
    """Gets and prints the content of the entry"""
    content = entry.get()
    print(content)  

Label(master, text="Input: ").grid(row=0, sticky=W)

entry = Entry(master)
entry.grid(row=0, column=1)

# Connect the entry with the return button
entry.bind('<Return>', return_entry) 

mainloop()

MySQL Multiple Left Joins

To display the all details for each news post title ie. "news.id" which is the primary key, you need to use GROUP BY clause for "news.id"

SELECT news.id, users.username, news.title, news.date,
       news.body, COUNT(comments.id)
FROM news
LEFT JOIN users
ON news.user_id = users.id
LEFT JOIN comments
ON comments.news_id = news.id
GROUP BY news.id

What do Clustered and Non clustered index actually mean?

Find below some characteristics of clustered and non-clustered indexes:

Clustered Indexes

  1. Clustered indexes are indexes that uniquely identify the rows in an SQL table.
  2. Every table can have exactly one clustered index.
  3. You can create a clustered index that covers more than one column. For example: create Index index_name(col1, col2, col.....).
  4. By default, a column with a primary key already has a clustered index.

Non-clustered Indexes

  1. Non-clustered indexes are like simple indexes. They are just used for fast retrieval of data. Not sure to have unique data.

What is a Maven artifact?

I know this is an ancient thread but I wanted to add a few nuances.

There are Maven artifacts, repository manager artifacts and then there are Maven Artifacts.

A Maven artifact is just as other commenters/responders say: it is a thing that is spat out by building a Maven project. That could be a .jar file, or a .war file, or a .zip file, or a .dll, or what have you.

A repository manager artifact is a thing that is, well, managed by a repository manager. A repository manager is basically a highly performant naming service for software executables and libraries. A repository manager doesn't care where its artifacts come from (maybe they came from a Maven build, or a local file, or an Ant build, or a by-hand compilation...).

A Maven Artifact is a Java class that represents the kind of "name" that gets dereferenced by a repository manager into a repository manager artifact. When used in this sense, an Artifact is just a glorified name made up of such parts as groupId, artifactId, version, scope, classifier and so on.

To put it all together:

  • Your Maven project probably depends on several Artifacts by way of its <dependency> elements.
  • Maven interacts with a repository manager to resolve those Artifacts into files by instructing the repository manager to send it some repository manager artifacts that correspond to the internal Artifacts.
  • Finally, after resolution, Maven builds your project and produces a Maven artifact. You may choose to "turn this into" a repository manager artifact by, in turn, using whatever tool you like, sending it to the repository manager with enough coordinating information that other people can find it when they ask the repository manager for it.

Hope that helps.

Can linux cat command be used for writing text to file?

cat can also be used following a | to write to a file, i.e. pipe feeds cat a stream of data

Axios having CORS issue

I had got the same CORS error while working on a Vue.js project. You can resolve this either by building a proxy server or another way would be to disable the security settings of your browser (eg, CHROME) for accessing cross origin apis (this is temporary solution & not the best way to solve the issue). Both these solutions had worked for me. The later solution does not require any mock server or a proxy server to be build. Both these solutions can be resolved at the front end.

You can disable the chrome security settings for accessing apis out of the origin by typing the below command on the terminal:

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --user-data-dir="/tmp/chrome_dev_session" --disable-web-security

After running the above command on your terminal, a new chrome window with security settings disabled will open up. Now, run your program (npm run serve / npm run dev) again and this time you will not get any CORS error and would be able to GET request using axios.

Hope this helps!

TypeError: Can't convert 'int' object to str implicitly

def attributeSelection():
balance = 25
print("Your SP balance is currently 25.")
strength = input("How much SP do you want to put into strength?")
balanceAfterStrength = balance - int(strength)
if balanceAfterStrength == 0:
    print("Your SP balance is now 0.")
    attributeConfirmation()
elif strength < 0:
    print("That is an invalid input. Restarting attribute selection. Keep an eye on your balance this time!")
    attributeSelection()
elif strength > balance:
    print("That is an invalid input. Restarting attribute selection. Keep an eye on your balance this time!")
    attributeSelection()
elif balanceAfterStrength > 0 and balanceAfterStrength < 26:
    print("Ok. You're balance is now at " + str(balanceAfterStrength) + " skill points.")
else:
    print("That is an invalid input. Restarting attribute selection.")
    attributeSelection()

Moving matplotlib legend outside of the axis makes it cutoff by the figure box

Here is another, very manual solution. You can define the size of the axis and paddings are considered accordingly (including legend and tickmarks). Hope it is of use to somebody.

Example (axes size are the same!):

enter image description here

Code:

#==================================================
# Plot table

colmap = [(0,0,1) #blue
         ,(1,0,0) #red
         ,(0,1,0) #green
         ,(1,1,0) #yellow
         ,(1,0,1) #magenta
         ,(1,0.5,0.5) #pink
         ,(0.5,0.5,0.5) #gray
         ,(0.5,0,0) #brown
         ,(1,0.5,0) #orange
         ]


import matplotlib.pyplot as plt
import numpy as np

import collections
df = collections.OrderedDict()
df['labels']        = ['GWP100a\n[kgCO2eq]\n\nasedf\nasdf\nadfs','human\n[pts]','ressource\n[pts]'] 
df['all-petroleum long name'] = [3,5,2]
df['all-electric']  = [5.5, 1, 3]
df['HEV']           = [3.5, 2, 1]
df['PHEV']          = [3.5, 2, 1]

numLabels = len(df.values()[0])
numItems = len(df)-1
posX = np.arange(numLabels)+1
width = 1.0/(numItems+1)

fig = plt.figure(figsize=(2,2))
ax = fig.add_subplot(111)
for iiItem in range(1,numItems+1):
  ax.bar(posX+(iiItem-1)*width, df.values()[iiItem], width, color=colmap[iiItem-1], label=df.keys()[iiItem])
ax.set(xticks=posX+width*(0.5*numItems), xticklabels=df['labels'])

#--------------------------------------------------
# Change padding and margins, insert legend

fig.tight_layout() #tight margins
leg = ax.legend(loc='upper left', bbox_to_anchor=(1.02, 1), borderaxespad=0)
plt.draw() #to know size of legend

padLeft   = ax.get_position().x0 * fig.get_size_inches()[0]
padBottom = ax.get_position().y0 * fig.get_size_inches()[1]
padTop    = ( 1 - ax.get_position().y0 - ax.get_position().height ) * fig.get_size_inches()[1]
padRight  = ( 1 - ax.get_position().x0 - ax.get_position().width ) * fig.get_size_inches()[0]
dpi       = fig.get_dpi()
padLegend = ax.get_legend().get_frame().get_width() / dpi 

widthAx = 3 #inches
heightAx = 3 #inches
widthTot = widthAx+padLeft+padRight+padLegend
heightTot = heightAx+padTop+padBottom

# resize ipython window (optional)
posScreenX = 1366/2-10 #pixel
posScreenY = 0 #pixel
canvasPadding = 6 #pixel
canvasBottom = 40 #pixel
ipythonWindowSize = '{0}x{1}+{2}+{3}'.format(int(round(widthTot*dpi))+2*canvasPadding
                                            ,int(round(heightTot*dpi))+2*canvasPadding+canvasBottom
                                            ,posScreenX,posScreenY)
fig.canvas._tkcanvas.master.geometry(ipythonWindowSize) 
plt.draw() #to resize ipython window. Has to be done BEFORE figure resizing!

# set figure size and ax position
fig.set_size_inches(widthTot,heightTot)
ax.set_position([padLeft/widthTot, padBottom/heightTot, widthAx/widthTot, heightAx/heightTot])
plt.draw()
plt.show()
#--------------------------------------------------
#==================================================

Sql Server string to date conversion

convert string to datetime in MSSQL implicitly

create table tmp 
(
  ENTRYDATETIME datetime
);

insert into tmp (ENTRYDATETIME) values (getdate());
insert into tmp (ENTRYDATETIME) values ('20190101');  --convert string 'yyyymmdd' to datetime


select * from tmp where ENTRYDATETIME > '20190925'  --yyyymmdd 
select * from tmp where ENTRYDATETIME > '20190925 12:11:09.555'--yyyymmdd HH:MIN:SS:MS



RHEL 6 - how to install 'GLIBC_2.14' or 'GLIBC_2.15'?

To install GLIBC_2.14 or GLIBC_2.15, download package from /gnu/libc/ index at

https://ftp.gnu.org/gnu/libc/

Then follow instructions listed by Timo:

For example glibc-2.14.tar.gz in your case.

  1. tar xvfz glibc-2.14.tar.gz

  2. cd glibc-2.14

  3. mkdir build

  4. cd build

  5. ../configure --prefix=/opt/glibc-2.14

  6. make

  7. sudo make install

  8. export LD_LIBRARY_PATH=/opt/glibc-2.14/lib:$LD_LIBRARY_PATH

HQL "is null" And "!= null" on an Oracle column

No. See also this link Handle conditional null in HQL for tips and tricks on how to handle comparisons with both null and non-null values.

Read file content from S3 bucket with boto3

Using the client instead of resource:

s3 = boto3.client('s3')
bucket='bucket_name'
result = s3.list_objects(Bucket = bucket, Prefix='/something/')
for o in result.get('Contents'):
    data = s3.get_object(Bucket=bucket, Key=o.get('Key'))
    contents = data['Body'].read()
    print(contents)

What is the difference between bindParam and bindValue?

From Prepared statements and stored procedures

Use bindParam to insert multiple rows with one time binding:

<?php

$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (?, ?)");
$stmt->bindParam(1, $name);
$stmt->bindParam(2, $value);

// insert one row
$name = 'one';
$value = 1;
$stmt->execute();

// insert another row with different values
$name = 'two';
$value = 2;
$stmt->execute();

How do I jump to a closing bracket in Visual Studio Code?

You can learn commands from the command palette Ctrl/Cmd + Shift + P). Look for "Go to Bracket". The keybinding is also shown there.

Convert JsonNode into POJO

In Jackson 2.4, you can convert as follows:

MyClass newJsonNode = jsonObjectMapper.treeToValue(someJsonNode, MyClass.class);

where jsonObjectMapper is a Jackson ObjectMapper.


In older versions of Jackson, it would be

MyClass newJsonNode = jsonObjectMapper.readValue(someJsonNode, MyClass.class);

Android ADB stop application command like "force-stop" for non rooted device

If you have a rooted device you can use kill command

Connect to your device with adb:

adb shell

Once the session is established, you have to escalade privileges:

su

Then

ps

will list running processes. Note down the PID of the process you want to terminate. Then get rid of it

kill PID

Why do we need to use flatMap?

When I started to have a look at Rxjs I also stumbled on that stone. What helped me is the following:

  • documentation from reactivex.io . For instance, for flatMap: http://reactivex.io/documentation/operators/flatmap.html
  • documentation from rxmarbles : http://rxmarbles.com/. You will not find flatMap there, you must look at mergeMap instead (another name).
  • the introduction to Rx that you have been missing: https://gist.github.com/staltz/868e7e9bc2a7b8c1f754. It addresses a very similar example. In particular it addresses the fact that a promise is akin to an observable emitting only one value.
  • finally looking at the type information from RxJava. Javascript not being typed does not help here. Basically if Observable<T> denotes an observable object which pushes values of type T, then flatMap takes a function of type T' -> Observable<T> as its argument, and returns Observable<T>. map takes a function of type T' -> T and returns Observable<T>.

    Going back to your example, you have a function which produces promises from an url string. So T' : string, and T : promise. And from what we said before promise : Observable<T''>, so T : Observable<T''>, with T'' : html. If you put that promise producing function in map, you get Observable<Observable<T''>> when what you want is Observable<T''>: you want the observable to emit the html values. flatMap is called like that because it flattens (removes an observable layer) the result from map. Depending on your background, this might be chinese to you, but everything became crystal clear to me with typing info and the drawing from here: http://reactivex.io/documentation/operators/flatmap.html.

How to convert NSDate into unix timestamp iphone sdk?

My preferred way is simply:

NSDate.date.timeIntervalSince1970;

ORA-01652: unable to extend temp segment by 128 in tablespace SYSTEM: How to extend?

Each tablespace has one or more datafiles that it uses to store data.

The max size of a datafile depends on the block size of the database. I believe that, by default, that leaves with you with a max of 32gb per datafile.

To find out if the actual limit is 32gb, run the following:

select value from v$parameter where name = 'db_block_size';

Compare the result you get with the first column below, and that will indicate what your max datafile size is.

I have Oracle Personal Edition 11g r2 and in a default install it had an 8,192 block size (32gb per data file).

Block Sz   Max Datafile Sz (Gb)   Max DB Sz (Tb)

--------   --------------------   --------------

   2,048                  8,192          524,264

   4,096                 16,384        1,048,528

   8,192                 32,768        2,097,056

  16,384                 65,536        4,194,112

  32,768                131,072        8,388,224

You can run this query to find what datafiles you have, what tablespaces they are associated with, and what you've currrently set the max file size to (which cannot exceed the aforementioned 32gb):

select bytes/1024/1024 as mb_size,
       maxbytes/1024/1024 as maxsize_set,
       x.*
from   dba_data_files x

MAXSIZE_SET is the maximum size you've set the datafile to. Also relevant is whether you've set the AUTOEXTEND option to ON (its name does what it implies).

If your datafile has a low max size or autoextend is not on you could simply run:

alter database datafile 'path_to_your_file\that_file.DBF' autoextend on maxsize unlimited;

However if its size is at/near 32gb an autoextend is on, then yes, you do need another datafile for the tablespace:

alter tablespace system add datafile 'path_to_your_datafiles_folder\name_of_df_you_want.dbf' size 10m autoextend on maxsize unlimited;

Finding rows that don't contain numeric data in Oracle

In contrast to SGB's answer, I prefer doing the regexp defining the actual format of my data and negating that. This allows me to define values like $DDD,DDD,DDD.DD In the OPs simple scenario, it would look like

SELECT * 
FROM table_with_column_to_search 
WHERE NOT REGEXP_LIKE(varchar_col_with_non_numerics, '^[0-9]+$');

which finds all non-positive integers. If you wau accept negatiuve integers also, it's an easy change, just add an optional leading minus.

SELECT * 
FROM table_with_column_to_search 
WHERE NOT REGEXP_LIKE(varchar_col_with_non_numerics, '^-?[0-9]+$');

accepting floating points...

SELECT * 
FROM table_with_column_to_search 
WHERE NOT REGEXP_LIKE(varchar_col_with_non_numerics, '^-?[0-9]+(\.[0-9]+)?$');

Same goes further with any format. Basically, you will generally already have the formats to validate input data, so when you will desire to find data that does not match that format ... it's simpler to negate that format than come up with another one; which in case of SGB's approach would be a bit tricky to do if you want more than just positive integers.

unique combinations of values in selected columns in pandas data frame and count

Slightly related, I was looking for the unique combinations and I came up with this method:

def unique_columns(df,columns):

    result = pd.Series(index = df.index)

    groups = meta_data_csv.groupby(by = columns)
    for name,group in groups:
       is_unique = len(group) == 1
       result.loc[group.index] = is_unique

    assert not result.isnull().any()

    return result

And if you only want to assert that all combinations are unique:

df1.set_index(['A','B']).index.is_unique

Ruby on Rails: How do I add placeholder text to a f.text_field?

With rails >= 3.0, you can simply use the placeholder option.

f.text_field :attr, placeholder: "placeholder text"

How to get value in the session in jQuery

Sessions are stored on the server and are set from server side code, not client side code such as JavaScript.

What you want is a cookie, someone's given a brilliant explanation in this Stack Overflow question here: How do I set/unset cookie with jQuery?

You could potentially use sessions and set/retrieve them with jQuery and AJAX, but it's complete overkill if Cookies will do the trick.

How do you add an image?

Shouldn't that be:

<xsl:value-of select="/root/Image/img/@src"/>

? It looks like you are trying to copy the entire Image/img node to the attribute @src

C/C++ NaN constant (literal)?

This can be done using the numeric_limits in C++:

http://www.cplusplus.com/reference/limits/numeric_limits/

These are the methods you probably want to look at:

infinity()  T   Representation of positive infinity, if available.
quiet_NaN() T   Representation of quiet (non-signaling) "Not-a-Number", if available.
signaling_NaN() T   Representation of signaling "Not-a-Number", if available.

PHP Warning: mysqli_connect(): (HY000/2002): Connection refused

In my case I was using XAMPP, and there was a log that told me the error. To find it, go to the XAMPP control panel, and click "Configure" for MySQL, then click on "Open Log."

The most current data of the log is at the bottom, and the log is organized by date, time, some number, and text in brackets that may say "Note" or "Error." One that says "Error" is likely causing the issue.

For me, my error was a tablespace that was causing an issue, so I deleted the database files at the given location.

Note: The tablespace files for your installation of XAMPP may be at a different location, but they were in /opt/lampp/var/mysql for me. I think that's typical of XAMPP on Debian-based distributions. Also, my instructions on what to click in the control panel to see the log may be a bit different for you because I'm running XAMPP on an Ubuntu-based distribution of Linux (Feren OS).

Reading tab-delimited file with Pandas - works on Windows, but not on Mac

The biggest clue is the rows are all being returned on one line. This indicates line terminators are being ignored or are not present.

You can specify the line terminator for csv_reader. If you are on a mac the lines created will end with \rrather than the linux standard \n or better still the suspenders and belt approach of windows with \r\n.

pandas.read_csv(filename, sep='\t', lineterminator='\r')

You could also open all your data using the codecs package. This may increase robustness at the expense of document loading speed.

import codecs

doc = codecs.open('document','rU','UTF-16') #open for reading with "universal" type set

df = pandas.read_csv(doc, sep='\t')

Base64 length calculation?

I think the given answers miss the point of the original question, which is how much space needs to be allocated to fit the base64 encoding for a given binary string of length n bytes.

The answer is (floor(n / 3) + 1) * 4 + 1

This includes padding and a terminating null character. You may not need the floor call if you are doing integer arithmetic.

Including padding, a base64 string requires four bytes for every three-byte chunk of the original string, including any partial chunks. One or two bytes extra at the end of the string will still get converted to four bytes in the base64 string when padding is added. Unless you have a very specific use, it is best to add the padding, usually an equals character. I added an extra byte for a null character in C, because ASCII strings without this are a little dangerous and you'd need to carry the string length separately.

How can I generate a tsconfig.json file?

I recommend to uninstall typescript first with the command:

npm uninstall -g typescript

then use the chocolatey package in order to run:

choco install typescript

in PowerShell.

How do I use popover from Twitter Bootstrap to display an image?

Here I have an example of Bootstrap 3 popover showing an image with the tittle above it when the mouse hovers over some text. I've put in some inline styling that you may want to take out or change.....

This also works pretty well on mobile devices because the image will popup on the first tap and the link will open on the second. html:

<h5><a href="#" title="Solid Tiles Template" target="_blank" data-image-url="http://s29.postimg.org/t5pik8lyf/tiles1_preview.jpg" class="preview" rel="popover" style="color: green; font-style: normal; font-weight: bolder; font-size: 16px;">Template Preview 1 <i class="fa fa-external-link"></i></a></h5>

<h5><a href="#" title="Clear Tiles Template" target="_blank" data-image-url="http://s9.postimg.org/rdonet7jj/tiles2_2_preview.jpg" class="preview" rel="popover" style="color: red; font-style: normal; font-weight: bolder; font-size: 16px;">Template Preview 2 <i class="fa fa-external-link"></i></a></h5>

<h5><a href="#" title="Clear Tiles Template" target="_blank" data-image-url="http://s27.postimg.org/8scrcdu9v/tiles3_3_preview.jpg" class="preview" rel="popover" style="color: blue; font-style: normal; font-weight: bolder; font-size: 16px;">Template Preview 3 <i class="fa fa-external-link"></i></a></h5>

js:

$('.preview').popover({
    'trigger':'hover',
    'html':true,
    'content':function(){
        return "<img src='"+$(this).data('imageUrl')+"'>";
    }
});

https://jsfiddle.net/pepsimax_uk/myk38781/3/

error C2065: 'cout' : undeclared identifier

I have seen that if you use

#include <iostream.h>

then you will get the problem.

If you use

#include <iostream>  

(notice - without the .h)

then you will not get the problem you mentioned.

How to conditional format based on multiple specific text in Excel

Suppose your "Don't Check" list is on Sheet2 in cells A1:A100, say, and your current client IDs are in Sheet1 in Column A.

What you would do is:

  1. Select the whole data table you want conditionally formatted in Sheet1
  2. Click Conditional Formatting > New Rule > Use a Formula to determine which cells to format
  3. In the formula bar, type in =ISNUMBER(MATCH($A1,Sheet2!$A$1:$A$100,0)) and select how you want those rows formatted

And that should do the trick.

Is JavaScript guaranteed to be single-threaded?

Well, Chrome is multiprocess, and I think every process deals with its own Javascript code, but as far as the code knows, it is "single-threaded".

There is no support whatsoever in Javascript for multi-threading, at least not explicitly, so it does not make a difference.

ERROR 1049 (42000): Unknown database 'mydatabasename'

La Chi's answer works for me.

You can view his/her answer in the comment of zessx answer in this page. But I initially have a problem with it if you also do just tweak his/her answer like this: mysql -h localhost -u root -p -D mydatabase < mydatabase.sql.

Also I would suggest that in the mydatabase.sql portion you include the direct location of it in your computer like "C:\Users\username\desktop".

Thank you.

How can I change eclipse's Internal Browser from IE to Firefox on Windows XP?

I don't know if this will help, but here's the SWT FAQ question How do I use Mozilla as the Browser's underlying renderer?

Edit: Having researched this further, it sounds like this isn't possible in Eclipse 3.4, but may be slated for a later release.

Spring-Boot: How do I set JDBC pool properties like maximum number of connections?

At the current version of Spring-Boot (1.4.1.RELEASE) , each pooling datasource implementation has its own prefix for properties.

For instance, if you are using tomcat-jdbc:

spring.datasource.tomcat.max-wait=10000

You can find the explanation out here

spring.datasource.max-wait=10000

this have no effect anymore.

"&" meaning after variable type

It means you're passing the variable by reference.

In fact, in a declaration of a type, it means reference, just like:

int x = 42;
int& y = x;

declares a reference to x, called y.

Remove first 4 characters of a string with PHP

You could use the substr function please check following example,

$string1 = "tarunmodi";
$first4 = substr($string1, 4);
echo $first4;

Output: nmodi

Convert string to float?

Try this:

String yourVal = "20.5";
float a = (Float.valueOf(yourVal)).floatValue(); 
System.out.println(a);

How to test if a string is JSON or not?

var parsedData;

try {
    parsedData = JSON.parse(data)
} catch (e) {
    // is not a valid JSON string
}

However, I will suggest to you that your http call / service should return always a data in the same format. So if you have an error, than you should have a JSON object that wrap this error:

{"error" : { "code" : 123, "message" : "Foo not supported" } } 

And maybe use as well as HTTP status a 5xx code.

Performing user authentication in Java EE / JSF using j_security_check

It should be mentioned that it is an option to completely leave authentication issues to the front controller, e.g. an Apache Webserver and evaluate the HttpServletRequest.getRemoteUser() instead, which is the JAVA representation for the REMOTE_USER environment variable. This allows also sophisticated log in designs such as Shibboleth authentication. Filtering Requests to a servlet container through a web server is a good design for production environments, often mod_jk is used to do so.

Python Pandas counting and summing specific conditions

You can first make a conditional selection, and sum up the results of the selection using the sum function.

>> df = pd.DataFrame({'a': [1, 2, 3]})
>> df[df.a > 1].sum()   
a    5
dtype: int64

Having more than one condition:

>> df[(df.a > 1) & (df.a < 3)].sum()
a    2
dtype: int64

Setting up and using environment variables in IntelliJ Idea

Path Variables dialog has nothing to do with the environment variables.

Environment variables can be specified in your OS or customized in the Run configuration:

env

How do I vertically align text in a paragraph?

User vertical-align: middle; along with text-align: center property

<!DOCTYPE html>
<html>
<head>
<style>
.center {
  border: 3px solid green;
  text-align: center;
}

.center p {
  display: inline-block;
  vertical-align: middle;
}
</style>
</head>
<body>

<h2>Centering</h2>
<p>In this example, we use the line-height property with a value that is equal to the height property to center the div element:</p>

<div class="center">
  <p>I am vertically and horizontally centered.</p>
</div>

</body>
</html>

Open multiple Projects/Folders in Visual Studio Code

You can install the Open Folder Context Menus for VS Code extension from Chris Dias

https://marketplace.visualstudio.com/items?itemName=chrisdias.vscode-opennewinstance

  • Restart Visual Studio Code
  • Right click a folder and select "Open New Workbench Here"

Open New Workbench Here

How to vertically align label and input in Bootstrap 3?

None of these solutions worked for me. But I was able to get vertical centering by using <div class="form-row align-items-center"> for each form row, per the Bootstrap examples.

Xcode 5.1 - No architectures to compile for (ONLY_ACTIVE_ARCH=YES, active arch=x86_64, VALID_ARCHS=i386)

In Valid architectures: Select each entry (release, debug) and build and press backspace. It should work

Find out whether radio button is checked with JQuery?

jQuery is still popular, but if you want to have no dependencies, see below. Short & clear function to find out if radio button is checked on ES-2015:

_x000D_
_x000D_
function getValueFromRadioButton( name ){_x000D_
  return [...document.getElementsByName(name)]_x000D_
         .reduce( (rez, btn) => (btn.checked ? btn.value : rez), null)_x000D_
}_x000D_
_x000D_
console.log( getValueFromRadioButton('payment') );
_x000D_
<div>  _x000D_
  <input type="radio" name="payment" value="offline">_x000D_
  <input type="radio" name="payment" value="online">_x000D_
  <input type="radio" name="payment" value="part" checked>_x000D_
  <input type="radio" name="payment" value="free">_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to tell if browser/tab is active

In addition to Richard Simões answer you can also use the Page Visibility API.

if (!document.hidden) {
    // do what you need
}

This specification defines a means for site developers to programmatically determine the current visibility state of the page in order to develop power and CPU efficient web applications.

Learn more (2019 update)

What is the difference between '@' and '=' in directive scope in AngularJS?

@ and = see other answers.

One gotcha about &
TL;DR;
& gets expression (not only function like in examples in other answers) from a parent, and sets it as a function in the directive, that calls the expression. And this function has the ability to replace any variable (even function name) of expression, by passing an object with the variables.

explained
& is an expression reference, that means if you pass something like <myDirective expr="x==y"></myDirective>
in the directive this expr will be a function, that calls the expression, like:
function expr(){return x == y}.
so in directive's html <button ng-click="expr()"></button> will call the expression. In js of the directive just $scope.expr() will call the expression too.
The expression will be called with $scope.x and $scope.y of the parent.
You have the ability to override the parameters!
If you set them by call, e.g. <button ng-click="expr({x:5})"></button>
then the expression will be called with your parameter x and parent's parameter y.
You can override both.
Now you know, why <button ng-click="functionFromParent({x:5})"></button> works.
Because it just calls the expression of parent (e.g. <myDirective functionFromParent="function1(x)"></myDirective>) and replaces possible values with your specified parameters, in this case x.
it could be:
<myDirective functionFromParent="function1(x) + 5"></myDirective>
or
<myDirective functionFromParent="function1(x) + z"></myDirective>
with child call:
<button ng-click="functionFromParent({x:5, z: 4})"></button>.
or even with function replacement:
<button ng-click="functionFromParent({function1: myfn, x:5, z: 4})"></button>.

it just an expression, does not matter if it is a function, or many functions, or just comparison. And you can replace any variable of this expression.

Examples:
directive template vs called code:
parent has defined $scope.x, $scope.y:
parent template: <myDirective expr="x==y"></myDirective>
<button ng-click="expr()"></button> calls $scope.x==$scope.y
<button ng-click="expr({x: 5})"></button> calls 5 == $scope.y
<button ng-click="expr({x:5, y:6})"></button> calls 5 == 6

parent has defined $scope.function1, $scope.x, $scope.y:
parent template: <myDirective expr="function1(x) + y"></myDirective>

<button ng-click="expr()"></button> calls $scope.function1($scope.x) + $scope.y
<button ng-click="expr({x: 5})"></button> calls $scope.function1(5) + $scope.y
<button ng-click="expr({x:5, y:6})"></button> calls $scope.function1(5) + 6
directive has $scope.myFn as function:
<button ng-click="expr({function1: myFn, x:5, y:6})"></button> calls $scope.myFn(5) + 6

How to use MapView in android using google map V2?

More complete sample from here and here.

Or you can check out my layout sample. p.s no need to put API key in the map view.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">

    <com.google.android.gms.maps.MapView
            android:id="@+id/map_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="2"
            />

    <ListView android:id="@+id/nearby_lv"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:background="@color/white"
              android:layout_weight="1"
            />

</LinearLayout>

Replace a newline in TSQL

If you have an issue where you only want to remove trailing characters, you can try this:

WHILE EXISTS
(SELECT * FROM @ReportSet WHERE
    ASCII(right(addr_3,1)) = 10
    OR ASCII(right(addr_3,1)) = 13
    OR ASCII(right(addr_3,1)) = 32)
BEGIN
    UPDATE @ReportSet
    SET addr_3 = LEFT(addr_3,LEN(addr_3)-1)
    WHERE 
    ASCII(right(addr_3,1)) = 10
    OR ASCII(right(addr_3,1)) = 13
    OR ASCII(right(addr_3,1)) = 32
END

This solved a problem I had with addresses where a procedure created a field with a fixed number of lines, even if those lines were empty. To save space in my SSRS report, I cut them down.

Sending SOAP request using Python Requests

It is indeed possible.

Here is an example calling the Weather SOAP Service using plain requests lib:

import requests
url="http://wsf.cdyne.com/WeatherWS/Weather.asmx?WSDL"
#headers = {'content-type': 'application/soap+xml'}
headers = {'content-type': 'text/xml'}
body = """<?xml version="1.0" encoding="UTF-8"?>
         <SOAP-ENV:Envelope xmlns:ns0="http://ws.cdyne.com/WeatherWS/" xmlns:ns1="http://schemas.xmlsoap.org/soap/envelope/" 
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
            <SOAP-ENV:Header/>
              <ns1:Body><ns0:GetWeatherInformation/></ns1:Body>
         </SOAP-ENV:Envelope>"""

response = requests.post(url,data=body,headers=headers)
print response.content

Some notes:

  • The headers are important. Most SOAP requests will not work without the correct headers. application/soap+xml is probably the more correct header to use (but the weatherservice prefers text/xml
  • This will return the response as a string of xml - you would then need to parse that xml.
  • For simplicity I have included the request as plain text. But best practise would be to store this as a template, then you can load it using jinja2 (for example) - and also pass in variables.

For example:

from jinja2 import Environment, PackageLoader
env = Environment(loader=PackageLoader('myapp', 'templates'))
template = env.get_template('soaprequests/WeatherSericeRequest.xml')
body = template.render()

Some people have mentioned the suds library. Suds is probably the more correct way to be interacting with SOAP, but I often find that it panics a little when you have WDSLs that are badly formed (which, TBH, is more likely than not when you're dealing with an institution that still uses SOAP ;) ).

You can do the above with suds like so:

from suds.client import Client
url="http://wsf.cdyne.com/WeatherWS/Weather.asmx?WSDL"
client = Client(url)
print client ## shows the details of this service

result = client.service.GetWeatherInformation() 
print result 

Note: when using suds, you will almost always end up needing to use the doctor!

Finally, a little bonus for debugging SOAP; TCPdump is your friend. On Mac, you can run TCPdump like so:

sudo tcpdump -As 0 

This can be helpful for inspecting the requests that actually go over the wire.

The above two code snippets are also available as gists:

Is there any way to show a countdown on the lockscreen of iphone?

There is no way to display interactive elements on the lockscreen or wallpaper with a non jailbroken iPhone.

I would recommend Countdown Widget it's free an you can display countdowns in the notification center which you can also access from your lockscreen.

Referring to a Column Alias in a WHERE Clause

You could refer to column alias but you need to define it using CROSS/OUTER APPLY:

SELECT s.logcount, s.logUserID, s.maxlogtm, c.daysdiff
FROM statslogsummary s
CROSS APPLY (SELECT DATEDIFF(day, s.maxlogtm, GETDATE()) AS daysdiff) c
WHERE c.daysdiff > 120;

DBFiddle Demo

Pros:

  • single definition of expression(easier to maintain/no need of copying-paste)
  • no need for wrapping entire query with CTE/outerquery
  • possibility to refer in WHERE/GROUP BY/ORDER BY
  • possible better performance(single execution)

How do I run pip on python for windows?

Maybe you'd like try run pip in Python shell like this:

>>> import pip
>>> pip.main(['install', 'requests'])

This will install requests package using pip.


Because pip is a module in standard library, but it isn't a built-in function(or module), so you need import it.

Other way, you should run pip in system shell(cmd. If pip is in path).

Switch statement fall-through...should it be allowed?

It is powerful and dangerous. The biggest problem with fall-through is that it's not explicit. For example, if you come across frequently-edited code that has a switch with fall-throughs, how do you know that's intentional and not a bug?

Anywhere I use it, I ensure that it's properly commented:

switch($var) {
    case 'first':
        // Fall-through
    case 'second':
        i++;
        break;
 }

SQL Stored Procedure: If variable is not null, update statement

Use a T-SQL IF:

IF @ABC IS NOT NULL AND @ABC != -1
    UPDATE [TABLE_NAME] SET XYZ=@ABC

Take a look at the MSDN docs.

What is difference between arm64 and armhf?

armhf stands for "arm hard float", and is the name given to a debian port for arm processors (armv7+) that have hardware floating point support.

On the beaglebone black, for example:

:~$ dpkg --print-architecture
armhf

Although other commands (such as uname -a or arch) will just show armv7l

:~$ cat /proc/cpuinfo 
processor       : 0
model name      : ARMv7 Processor rev 2 (v7l)
BogoMIPS        : 995.32
Features        : half thumb fastmult vfp edsp thumbee neon vfpv3 tls
...

The vfpv3 listed under Features is what refers to the floating point support.

Incidentally, armhf, if your processor supports it, basically supersedes Raspbian, which if I understand correctly was mainly a rebuild of armhf with work arounds to deal with the lack of floating point support on the original raspberry pi's. Nowdays, of course, there's a whole ecosystem build up around Raspbian, so they're probably not going to abandon it. However, this is partly why the beaglebone runs straight debian, and that's ok even if you're used to Raspbian, unless you want some of the special included non-free software such as Mathematica.

Set specific precision of a BigDecimal

Try this code ...

    Integer perc = 5;
    BigDecimal spread = BigDecimal.ZERO; 
    BigDecimal perc = spread.setScale(perc,BigDecimal.ROUND_HALF_UP);
    System.out.println(perc);

Result: 0.00000

Generate random colors (RGB)

Output in the form of (r,b,g) its look like (255,155,100)

from numpy import random
color = (random.randint(0, 255), random.randint(0, 255), random.randint(0, 255))

How to set space between listView Items in Android

Maybe you can try to add android:layout_marginTop = "15dp" and android:layout_marginBottom = "15dp" in the outermost Layout

How to pass object with NSNotificationCenter

Swift 2 Version

As @Johan Karlsson pointed out... I was doing it wrong. Here's the proper way to send and receive information with NSNotificationCenter.

First, we look at the initializer for postNotificationName:

init(name name: String,
   object object: AnyObject?,
 userInfo userInfo: [NSObject : AnyObject]?)

source

We'll be passing our information using the userInfo param. The [NSObject : AnyObject] type is a hold-over from Objective-C. So, in Swift land, all we need to do is pass in a Swift dictionary that has keys that are derived from NSObject and values which can be AnyObject.

With that knowledge we create a dictionary which we'll pass into the object parameter:

 var userInfo = [String:String]()
 userInfo["UserName"] = "Dan"
 userInfo["Something"] = "Could be any object including a custom Type."

Then we pass the dictionary into our object parameter.

Sender

NSNotificationCenter.defaultCenter()
    .postNotificationName("myCustomId", object: nil, userInfo: userInfo)

Receiver Class

First we need to make sure our class is observing for the notification

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("btnClicked:"), name: "myCustomId", object: nil)   
}
    

Then we can receive our dictionary:

func btnClicked(notification: NSNotification) {
   let userInfo : [String:String!] = notification.userInfo as! [String:String!]
   let name = userInfo["UserName"]
   print(name)
}

How to set max width of an image in CSS

Given your container width 600px.

If you want only bigger images than that to fit inside, add: CSS:

#ImageContainer img {
    max-width: 600px;
}

If you want ALL images to take the avaiable (600px) space:

#ImageContainer img {
    width: 600px;
}

Malformed String ValueError ast.literal_eval() with String representation of Tuple

I know this is an old question, but I think found a very simple answer, in case anybody needs it.

If you put string quotes inside your string ("'hello'"), ast_literaleval() will understand it perfectly.

You can use a simple function:

    def doubleStringify(a):
        b = "\'" + a + "\'"
        return b

Or probably more suitable for this example:

    def perfectEval(anonstring):
        try:
            ev = ast.literal_eval(anonstring)
            return ev
        except ValueError:
            corrected = "\'" + anonstring + "\'"
            ev = ast.literal_eval(corrected)
            return ev

How to clear text area with a button in html using javascript?

You need to attach a click event handler and clear the contents of the textarea from that handler.

HTML

<input type="button" value="Clear" id="clear"> 
<textarea id='output' rows=20 cols=90></textarea>

JS

var input = document.querySelector('#clear');
var textarea = document.querySelector('#output');

input.addEventListener('click', function () {
    textarea.value = '';
}, false);

and here's the working demo.

HTML character codes for this ? or this ?

There are several correct ways to display a down-pointing and upward-pointing triangle.

Method 1 : use decimal HTML entity

HTML :

&#9650;
&#9660;

Method 2 : use hexidecimal HTML entity

HTML :

&#x25B2;
&#x25BC;

Method 3 : use character directly

HTML :

?
?

Method 4 : use CSS

HTML :

<span class='icon-up'></span>
<span class='icon-down'></span>

CSS :

.icon-up:before {
    content: "\25B2";
}

.icon-down:before {
    content: "\25BC";
}

Each of these three methods should have the same output. For other symbols, the same three options exist. Some even have a fourth option, allowing you to use a string based reference (eg. &hearts; to display ?).

You can use a reference website like Unicode-table.com to find which icons are supported in UNICODE and which codes they correspond with. For example, you find the values for the down-pointing triangle at http://unicode-table.com/en/25BC/.

Note that these methods are sufficient only for icons that are available by default in every browser. For symbols like ?,?,?,?,?,? or ?, this is far less likely to be the case. While it is possible to provide cross-browser support for other UNICODE symbols, the procedure is a bit more complicated.

If you want to know how to add support for less common UNICODE characters, see Create webfont with Unicode Supplementary Multilingual Plane symbols for more info on how to do this.


Background images

A totally different strategy is the use of background-images instead of fonts. For optimal performance, it's best to embed the image in your CSS file by base-encoding it, as mentioned by eg. @weasel5i2 and @Obsidian. I would recommend the use of SVG rather than GIF, however, is that's better both for performance and for the sharpness of your symbols.

This following code is the base64 for and SVG version of the enter image description here icon :

/* size: 0.9kb */
url(data:image/svg+xml;base64,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

When to use background-images or fonts

For many use cases, SVG-based background images and icon fonts are largely equivalent with regards to performance and flexibility. To decide which to pick, consider the following differences:

SVG images

  • They can have multiple colors
  • They can embed their own CSS and/or be styled by the HTML document
  • They can be loaded as a seperate file, embedded in CSS AND embedded in HTML
  • Each symbol is represented by XML code or base64 code. You cannot use the character directly within your code editor or use an HTML entity
  • Multiple uses of the same symbol implies duplication of the symbol when XML code is embedded in the HTML. Duplication is not required when embedding the file in the CSS or loading it as a seperate file
  • You can not use color, font-size, line-height, background-color or other font related styling rules to change the display of your icon, but you can reference different components of the icon as shapes individually.
  • You need some knowledge of SVG and/or base64 encoding
  • Limited or no support in old versions of IE

Icon fonts

  • An icon can have but one fill color, one background color, etc.
  • An icon can be embedded in CSS or HTML. In HTML, you can use the character directly or use an HTML entity to represent it.
  • Some symbols can be displayed without the use of a webfont. Most symbols cannot.
  • Multiple uses of the same symbol implies duplication of the symbol when your character embedded in the HTML. Duplication is not required when embedding the file in the CSS.
  • You can use color, font-size, line-height, background-color or other font related styling rules to change the display of your icon
  • You need no special technical knowledge
  • Support in all major browsers, including old versions of IE

Personally, I would recommend the use of background-images only when you need multiple colors and those color can't be achieved by means of color, background-color and other color-related CSS rules for fonts.

The main benefit of using SVG images is that you can give different components of a symbol their own styling. If you embed your SVG XML code in the HTML document, this is very similar to styling the HTML. This would, however, result in a web page that uses both HTML tags and SVG tags, which could significantly reduce the readability of a webpage. It also adds extra bloat if the symbol is repeated across multiple pages and you need to consider that old versions of IE have no or limited support for SVG.

Use jQuery to change value of a label

Validation (HTML5): Attribute 'name' is not a valid attribute of element 'label'.

AngularJS: Basic example to use authentication in Single Page Application

In angularjs you can create the UI part, service, Directives and all the part of angularjs which represent the UI. It is nice technology to work on.

As any one who new into this technology and want to authenticate the "User" then i suggest to do it with the power of c# web api. for that you can use the OAuth specification which will help you to built a strong security mechanism to authenticate the user. once you build the WebApi with OAuth you need to call that api for token:

_x000D_
_x000D_
var _login = function (loginData) {_x000D_
 _x000D_
        var data = "grant_type=password&username=" + loginData.userName + "&password=" + loginData.password;_x000D_
 _x000D_
        var deferred = $q.defer();_x000D_
 _x000D_
        $http.post(serviceBase + 'token', data, { headers: { 'Content-Type': 'application/x-www-form-urlencoded' } }).success(function (response) {_x000D_
 _x000D_
            localStorageService.set('authorizationData', { token: response.access_token, userName: loginData.userName });_x000D_
 _x000D_
            _authentication.isAuth = true;_x000D_
            _authentication.userName = loginData.userName;_x000D_
 _x000D_
            deferred.resolve(response);_x000D_
 _x000D_
        }).error(function (err, status) {_x000D_
            _logOut();_x000D_
            deferred.reject(err);_x000D_
        });_x000D_
 _x000D_
        return deferred.promise;_x000D_
 _x000D_
    };_x000D_
 
_x000D_
_x000D_
_x000D_

and once you get the token then you request the resources from angularjs with the help of Token and access the resource which kept secure in web Api with OAuth specification.

Please have a look into the below article for more help:-

http://bitoftech.net/2014/06/09/angularjs-token-authentication-using-asp-net-web-api-2-owin-asp-net-identity/

Get parent directory of running script

If I properly understood your question, supposing your running script is

/relative/path/to/script/index.php

This would give you the parent directory of your running script relative to the document www:

$parent_dir = dirname(dirname($_SERVER['SCRIPT_NAME'])) . '/';
//$parent_dir will be '/relative/path/to/'

If you want the parent directory of your running script relative to server root:

$parent_dir = dirname(dirname($_SERVER['SCRIPT_FILENAME'])) . '/';
//$parent_dir will be '/root/some/path/relative/path/to/'

PHP How to fix Notice: Undefined variable:

Declare them before the while loop.

$hn = "";
$pid = "";
$datereg = "";
$prefix = "";
$fname = "";
$lname = "";
$age = "";
$sex = "";

You are getting the notice because the variables are declared and assigned inside the loop.

Comparing two input values in a form validation with AngularJS

No need a function or a directive. Just compare their $modelValue from the view:

ng-show="formName.email.$modelValue !== formName.confirmEmail.$modelValue"

More detailed example:

<span ng-show="(formName.email.$modelValue !== formName.confirmEmail.$modelValue) 
                && formName.confirmEmail.$touched
                && !formName.confirmEmail.$error.required">Email does not match.</span>

Please note that the ConfirmEmail is outside the ViewModel; it's property of the $scope. It doesn't need to be submitted.

Input and output numpy arrays to h5py

h5py provides a model of datasets and groups. The former is basically arrays and the latter you can think of as directories. Each is named. You should look at the documentation for the API and examples:

http://docs.h5py.org/en/latest/quick.html

A simple example where you are creating all of the data upfront and just want to save it to an hdf5 file would look something like:

In [1]: import numpy as np
In [2]: import h5py
In [3]: a = np.random.random(size=(100,20))
In [4]: h5f = h5py.File('data.h5', 'w')
In [5]: h5f.create_dataset('dataset_1', data=a)
Out[5]: <HDF5 dataset "dataset_1": shape (100, 20), type "<f8">

In [6]: h5f.close()

You can then load that data back in using: '

In [10]: h5f = h5py.File('data.h5','r')
In [11]: b = h5f['dataset_1'][:]
In [12]: h5f.close()

In [13]: np.allclose(a,b)
Out[13]: True

Definitely check out the docs:

http://docs.h5py.org

Writing to hdf5 file depends either on h5py or pytables (each has a different python API that sits on top of the hdf5 file specification). You should also take a look at other simple binary formats provided by numpy natively such as np.save, np.savez etc:

http://docs.scipy.org/doc/numpy/reference/routines.io.html

Reading my own Jar's Manifest

A simpler way to do this is to use getPackage(). For example, to get Implementation-Version:

Application.class.getPackage().getImplementationVersion()

how to create a cookie and add to http response from inside my service layer?

In Spring MVC you get the HtppServletResponce object by default .

   @RequestMapping("/myPath.htm")
    public ModelAndView add(HttpServletRequest request,
         HttpServletResponse response) throws Exception{
            //Do service call passing the response
    return new ModelAndView("CustomerAddView");
    }

//Service code
Cookie myCookie =
  new Cookie("name", "val");
  response.addCookie(myCookie);

How to remove outliers from a dataset

x<-quantile(retentiondata$sum_dec_incr,c(0.01,0.99))
data_clean <- data[data$attribute >=x[1] & data$attribute<=x[2],]

I find this very easy to remove outliers. In the above example I am just extracting 2 percentile to 98 percentile of attribute values.

Get the position of a spinner in Android

    final int[] positions=new int[2]; 
    Spinner sp=findViewByID(R.id.spinner);

    sp.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1,
                int arg2, long arg3) {
            // TODO Auto-generated method stub
            Toast.makeText( arg2....);
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub

        }
    });

No log4j2 configuration file found. Using default configuration: logging only errors to the console

Tested with: log4j-ap 2.13.2, log4j-core 2.13.2.

  1. Keep XML file directly under below folder structure. src/main/java
  2. In the POM:
    <build>   
 <resources>       
             <resource>
                <filtering>false</filtering>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>             
            </resource>
 </resources>  
</build>
  1. Clean and build.

Input placeholders for Internet Explorer

Here is a pure javascript function (no jquery needed) that will create placeholders for IE 8 and below and it works for passwords as well. It reads the HTML5 placeholder attribute and creates a span element behind the form element and makes the form element background transparent:

_x000D_
_x000D_
/* Function to add placeholders to form elements on IE 8 and below */_x000D_
function add_placeholders(fm) { _x000D_
 for (var e = 0; e < document.fm.elements.length; e++) {_x000D_
  if (fm.elements[e].placeholder != undefined &&_x000D_
  document.createElement("input").placeholder == undefined) { // IE 8 and below     _x000D_
   fm.elements[e].style.background = "transparent";_x000D_
   var el = document.createElement("span");_x000D_
   el.innerHTML = fm.elements[e].placeholder;_x000D_
   el.style.position = "absolute";_x000D_
   el.style.padding = "2px;";_x000D_
   el.style.zIndex = "-1";_x000D_
   el.style.color = "#999999";_x000D_
   fm.elements[e].parentNode.insertBefore(el, fm.elements[e]);_x000D_
   fm.elements[e].onfocus = function() {_x000D_
     this.style.background = "yellow"; _x000D_
   }_x000D_
   fm.elements[e].onblur = function() {_x000D_
    if (this.value == "") this.style.background = "transparent";_x000D_
    else this.style.background = "white"; _x000D_
   }  _x000D_
  } _x000D_
 }_x000D_
}_x000D_
_x000D_
add_placeholders(document.getElementById('fm'))
_x000D_
<form id="fm">_x000D_
  <input type="text" name="email" placeholder="Email">_x000D_
  <input type="password" name="password" placeholder="Password">_x000D_
  <textarea name="description" placeholder="Description"></textarea>_x000D_
</form>
_x000D_
_x000D_
_x000D_

installing python packages without internet and using source code as .tar.gz and .whl

This isn't an answer. I was struggling but then realized that my install was trying to connect to internet to download dependencies.

So, I downloaded and installed dependencies first and then installed with below command. It worked

python -m pip install filename.tar.gz

How to change fonts in matplotlib (python)?

I prefer to employ:

from matplotlib import rc
#rc('font',**{'family':'sans-serif','sans-serif':['Helvetica']})
rc('font',**{'family':'serif','serif':['Times']})
rc('text', usetex=True)

Why does HTML think “chucknorris” is a color?

chucknorris starts with c, and the browser reads it into a hexadecimal value.

Because A, B, C, D, E, and F are characters in hexadecimal.

The browser converts chucknorris to a hexadecimal value, C00C00000000.

Then the C00C00000000 hexadecimal value is converted to RGB format (divided by 3):

C00C00000000 ? R:C00C, G:0000, B:0000

The browser needs only two digits to indicate the colour:

R:C00C, G:0000, B:0000 ? R:C0, G:00, B:00 ? C00000

Finally, show bgcolor = C00000 in the web browser.

Here's an example demonstrating it:

_x000D_
_x000D_
<table>
  <tr>
    <td bgcolor="chucknorris" cellpadding="10" width="150" align="center">chucknorris</td>
    <td bgcolor="c00c00000000" cellpadding="10" width="150" align="center">c00c00000000</td>
    <td bgcolor="c00000" cellpadding="10" width="150" align="center">c00000</td>
  </tr>
</table>
_x000D_
_x000D_
_x000D_

How to echo in PHP, HTML tags

This will also work fine with double quotes. To echo any html_tag with double quotes we just need to remember one thing, Do not use any other double quotes(") in the middle.

<?php
    echo "
    <div>
        <h3><a href='https://stackoverflow.com/questions/3931351/how-to-echo-in-php-html-tags'>First</a></h3>
        <div>Lorem ipsum dolor sit amet.</div>
        </div>
    <div>";
?>

Notice here the link inside the PHP echo is enclosed within the single quotes. This is the precaution you should take while using the double quotes for this purpose.

Remove innerHTML from div

$('div').html('');

But why are you clearing, divToUpdate.html(data); will completely replace the old HTML.

Looping over elements in jQuery

Depending on what you need each child for (if you're looking to post it somewhere via AJAX) you can just do...

$("#formID").serialize()

It creates a string for you with all of the values automatically.

As for looping through objects, you can also do this.

$.each($("input, select, textarea"), function(i,v) {
    var theTag = v.tagName;
    var theElement = $(v);
    var theValue = theElement.val();
});

How to generate unique ID with node.js

used https://www.npmjs.com/package/uniqid in npm

npm i uniqid

It will always create unique id's based on the current time, process and machine name.

  • With the current time the ID's are always unique in a single process.
  • With the Process ID the ID's are unique even if called at the same time from multiple processes.
  • With the MAC Address the ID's are unique even if called at the same time from multiple machines and processes.

Features:-

  • Very fast
  • Generates unique id's on multiple processes and machines even if called at the same time.
  • Shorter 8 and 12 byte versions with less uniqueness.

How do I get PHP errors to display?

This always works for me:

ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);

However, this doesn't make PHP to show parse errors - the only way to show those errors is to modify your php.ini with this line:

display_errors = on

(if you don't have access to php.ini, then putting this line in .htaccess might work too):

php_flag display_errors 1

How to convert a huge list-of-vector to a matrix more efficiently?

I think you want

output <- do.call(rbind,lapply(z,matrix,ncol=10,byrow=TRUE))

i.e. combining @BlueMagister's use of do.call(rbind,...) with an lapply statement to convert the individual list elements into 11*10 matrices ...

Benchmarks (showing @flodel's unlist solution is 5x faster than mine, and 230x faster than the original approach ...)

n <- 1000
z <- replicate(n,matrix(1:110,ncol=10,byrow=TRUE),simplify=FALSE)
library(rbenchmark)
origfn <- function(z) {
    output <- NULL 
    for(i in 1:length(z))
        output<- rbind(output,matrix(z[[i]],ncol=10,byrow=TRUE))
}
rbindfn <- function(z) do.call(rbind,lapply(z,matrix,ncol=10,byrow=TRUE))
unlistfn <- function(z) matrix(unlist(z), ncol = 10, byrow = TRUE)

##          test replications elapsed relative user.self sys.self 
## 1   origfn(z)          100  36.467  230.804    34.834    1.540  
## 2  rbindfn(z)          100   0.713    4.513     0.708    0.012 
## 3 unlistfn(z)          100   0.158    1.000     0.144    0.008 

If this scales appropriately (i.e. you don't run into memory problems), the full problem would take about 130*0.2 seconds = 26 seconds on a comparable machine (I did this on a 2-year-old MacBook Pro).

Anaconda site-packages

Run this inside python shell:

from distutils.sysconfig import get_python_lib
print(get_python_lib())

Postgresql, update if row with some unique value exists, else insert

This has been asked many times. A possible solution can be found here: https://stackoverflow.com/a/6527838/552671

This solution requires both an UPDATE and INSERT.

UPDATE table SET field='C', field2='Z' WHERE id=3;
INSERT INTO table (id, field, field2)
       SELECT 3, 'C', 'Z'
       WHERE NOT EXISTS (SELECT 1 FROM table WHERE id=3);

With Postgres 9.1 it is possible to do it with one query: https://stackoverflow.com/a/1109198/2873507

What exactly are iterator, iterable, and iteration?

I don't think that you can get it much simpler than the documentation, however I'll try:

  • Iterable is something that can be iterated over. In practice it usually means a sequence e.g. something that has a beginning and an end and some way to go through all the items in it.
  • You can think Iterator as a helper pseudo-method (or pseudo-attribute) that gives (or holds) the next (or first) item in the iterable. (In practice it is just an object that defines the method next())

  • Iteration is probably best explained by the Merriam-Webster definition of the word :

b : the repetition of a sequence of computer instructions a specified number of times or until a condition is met — compare recursion

using sql count in a case statement

SELECT 
    COUNT(CASE WHEN rsp_ind = 0 then 1 ELSE NULL END) as "New",
    COUNT(CASE WHEN rsp_ind = 1 then 1 ELSE NULL END) as "Accepted"
from tb_a

You can see the output for this request HERE

What is a reasonable length limit on person "Name" fields?

The average first name is about 6 letters. That leaves 43 for a last name. :) Seems like you could probably shorten it if you like.

The main question is how many rows do you think you will have? I don't think varchar(50) is going to kill you until you get several million rows.

Can "git pull --all" update all my local branches?

To complete the answer by Matt Connolly, this is a safer way to update local branch references that can be fast-forwarded, without checking out the branch. It does not update branches that cannot be fast-forwarded (i.e. that have diverged), and it does not update the branch that is currently checked out (because then the working copy should be updated as well).

git fetch

head="$(git symbolic-ref HEAD)"
git for-each-ref --format="%(refname) %(upstream)" refs/heads | while read ref up; do
    if [ -n "$up" -a "$ref" != "$head" ]; then
        mine="$(git rev-parse "$ref")"
        theirs="$(git rev-parse "$up")"
        base="$(git merge-base "$ref" "$up")"
        if [ "$mine" != "$theirs" -a "$mine" == "$base" ]; then
            git update-ref "$ref" "$theirs"
        fi
    fi
done

Jasmine.js comparing arrays

just for the record you can always compare using JSON.stringify

const arr = [1,2,3]; expect(JSON.stringify(arr)).toBe(JSON.stringify([1,2,3])); expect(JSON.stringify(arr)).toEqual(JSON.stringify([1,2,3]));

It's all meter of taste, this will also work for complex literal objects

Android update activity UI from service

Clyde's solution works, but it is a broadcast, which I am pretty sure will be less efficient than calling a method directly. I could be mistaken, but I think the broadcasts are meant more for inter-application communication.

I'm assuming you already know how to bind a service with an Activity. I do something sort of like the code below to handle this kind of problem:

class MyService extends Service {
    MyFragment mMyFragment = null;
    MyFragment mMyOtherFragment = null;

    private void networkLoop() {
        ...

        //received new data for list.
        if(myFragment != null)
            myFragment.updateList();
        }

        ...

        //received new data for textView
        if(myFragment !=null)
            myFragment.updateText();

        ...

        //received new data for textView
        if(myOtherFragment !=null)
            myOtherFragment.updateSomething();

        ...
    }
}


class MyFragment extends Fragment {

    public void onResume() {
        super.onResume()
        //Assuming your activity bound to your service
        getActivity().mMyService.mMyFragment=this;
    }

    public void onPause() {
        super.onPause()
        //Assuming your activity bound to your service
        getActivity().mMyService.mMyFragment=null;
    }

    public void updateList() {
        runOnUiThread(new Runnable() {
            public void run() {
                //Update the list.
            }
        });
    }

    public void updateText() {
       //as above
    }
}

class MyOtherFragment extends Fragment {
             public void onResume() {
        super.onResume()
        //Assuming your activity bound to your service
        getActivity().mMyService.mMyOtherFragment=this;
    }

    public void onPause() {
        super.onPause()
        //Assuming your activity bound to your service
        getActivity().mMyService.mMyOtherFragment=null;
    }

    public void updateSomething() {//etc... }
}

I left out bits for thread safety, which is essential. Make sure to use locks or something like that when checking and using or changing the fragment references on the service.

Iterate over array of objects in Typescript

You can use the built-in forEach function for arrays.

Like this:

//this sets all product descriptions to a max length of 10 characters
data.products.forEach( (element) => {
    element.product_desc = element.product_desc.substring(0,10);
});

Your version wasn't wrong though. It should look more like this:

for(let i=0; i<data.products.length; i++){
    console.log(data.products[i].product_desc); //use i instead of 0
}

How do you attach and detach from Docker's process?

In the same shell, hold ctrl key and press keys p then q