Programs & Examples On #Treemaps

Http Get using Android HttpURLConnection

A more contemporary way of doing it on a separate thread using Tasks and Kotlin

private val mExecutor: Executor = Executors.newSingleThreadExecutor()

private fun createHttpTask(u:String): Task<String> {
    return Tasks.call(mExecutor, Callable<String>{
        val url = URL(u)
        val conn: HttpURLConnection = url.openConnection() as HttpURLConnection
        conn.requestMethod = "GET"
        conn.connectTimeout = 3000
        conn.readTimeout = 3000
        val rc = conn.responseCode
        if ( rc != HttpURLConnection.HTTP_OK) {
            throw java.lang.Exception("Error: ${rc}")
        }
        val inp: InputStream = BufferedInputStream(conn.inputStream)
        val resp: String = inp.bufferedReader(UTF_8).use{ it.readText() }
        return@Callable resp
    })
}

and now you can use it like below in many places:

            createHttpTask("https://google.com")
                    .addOnSuccessListener {
                        Log.d("HTTP", "Response: ${it}") // 'it' is a response string here
                    }
                    .addOnFailureListener {
                        Log.d("HTTP", "Error: ${it.message}") // 'it' is an Exception object here
                    }

Java generics - get class?

I'm not 100% sure if this works in all cases (needs at least Java 1.5):

import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;

public class Main 
{
    public class A
    {   
    }

    public class B extends A
    {       
    }


    public Map<A, B> map = new HashMap<Main.A, Main.B>();

    public static void main(String[] args) 
    {

        try
        {
            Field field = Main.class.getField("map");           
            System.out.println("Field " + field.getName() + " is of type " + field.getType().getSimpleName());

            Type genericType = field.getGenericType();

            if(genericType instanceof ParameterizedType)
            {
                ParameterizedType type = (ParameterizedType) genericType;               
                Type[] typeArguments = type.getActualTypeArguments();

                for(Type typeArgument : typeArguments) 
                {   
                    Class<?> classType = ((Class<?>)typeArgument);                  
                    System.out.println("Field " + field.getName() + " has a parameterized type of " + classType.getSimpleName());
                }
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }    
}

This will output:

Field map is of type Map
Field map has a parameterized type of A
Field map has a parameterized type of B

laravel compact() and ->with()

Route::get('/', function () {
    return view('greeting', ['name' => 'James']);
});
<html>
    <body>
        <h1>Hello, {{ $name }}</h1>
    </body>
</html>

or

public function index($id)
{
    $category = Category::find($id);
    $topics = $category->getTopicPaginator();
    $message = Message::find(1);

    // here I would just use "->with([$category, $topics, $message])"
    return View::make('category.index')->with(compact('category', 'topics', 'message'));
}

Download files from server php

If the folder is accessible from the browser (not outside the document root of your web server), then you just need to output links to the locations of those files. If they are outside the document root, you will need to have links, buttons, whatever, that point to a PHP script that handles getting the files from their location and streaming to the response.

Google Maps API warning: NoApiKeys

Creating and using the key is the way to go. The usage is free until your application reaches 25.000 calls per day on 90 consecutive days.

BTW.: In the google Developer documentation it says you shall add the api key as option {key:yourKey} when calling the API to create new instances. This however doesn't shush the console warning. You have to add the key as a parameter when including the api.

<script src="https://maps.googleapis.com/maps/api/js?key=yourKEYhere"></script>

Get the key here: GoogleApiKey Generation site

dataframe: how to groupBy/count then filter on count in Scala

So, is that a behavior to expect, a bug

Truth be told I am not sure. It looks like parser is interpreting count not as a column name but a function and expects following parentheses. Looks like a bug or at least a serious limitation of the parser.

is there a canonical way to go around?

Some options have been already mentioned by Herman and mattinbits so here more SQLish approach from me:

import org.apache.spark.sql.functions.count

df.groupBy("x").agg(count("*").alias("cnt")).where($"cnt"  > 2)

What is the difference between PUT, POST and PATCH?

here is a simple description of all:

  • POST is always for creating a resource ( does not matter if it was duplicated )
  • PUT is for checking if resource is exists then update , else create new resource
  • PATCH is always for update a resource

What is the use of style="clear:both"?

Just to add to RichieHindle's answer, check out Floatutorial, which walks you through how CSS floating and clearing works.

CSS3 transition on click using pure CSS

Voila!

_x000D_
_x000D_
div {_x000D_
  background-color: red;_x000D_
  color: white;_x000D_
  font-weight: bold;_x000D_
  width: 48px;_x000D_
  height: 48px;  _x000D_
  transform: rotate(360deg);_x000D_
  transition: transform 0.5s;_x000D_
}_x000D_
_x000D_
div:active {_x000D_
  transform: rotate(0deg);_x000D_
  transition:  0s;_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

Tick symbol in HTML/XHTML

Coming very late to the party, I found that &check; (✓) worked in Opera. I haven't tested it on any other browsers, but it might be useful for some people.

Bootstrap Dropdown with Hover

The solution I am proposing detects if its not touch device and that the navbar-toggle (hamburger menu) is not visible and makes the parent menu item revealing submenu on hover and and follow its link on click.

Also makes tne margin-top 0 because the gap between the navbar and the menu in some browser will not let you hover to the subitems

_x000D_
_x000D_
$(function(){_x000D_
    function is_touch_device() {_x000D_
        return 'ontouchstart' in window        // works on most browsers _x000D_
        || navigator.maxTouchPoints;       // works on IE10/11 and Surface_x000D_
    };_x000D_
_x000D_
    if(!is_touch_device() && $('.navbar-toggle:hidden')){_x000D_
      $('.dropdown-menu', this).css('margin-top',0);_x000D_
      $('.dropdown').hover(function(){ _x000D_
          $('.dropdown-toggle', this).trigger('click').toggleClass("disabled"); _x000D_
      });   _x000D_
    }_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<ul id="nav" class="nav nav-pills clearfix right" role="tablist">_x000D_
    <li><a href="#">menuA</a></li>_x000D_
    <li><a href="#">menuB</a></li>_x000D_
    <li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown">menuC</a>_x000D_
        <ul id="products-menu" class="dropdown-menu clearfix" role="menu">_x000D_
            <li><a href="">A</a></li>_x000D_
            <li><a href="">B</a></li>_x000D_
            <li><a href="">C</a></li>_x000D_
            <li><a href="">D</a></li>_x000D_
        </ul>_x000D_
    </li>_x000D_
    <li><a href="#">menuD</a></li>_x000D_
    <li><a href="#">menuE</a></li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

_x000D_
_x000D_
$(function(){_x000D_
  $("#nav .dropdown").hover(_x000D_
    function() {_x000D_
      $('#products-menu.dropdown-menu', this).stop( true, true ).fadeIn("fast");_x000D_
      $(this).toggleClass('open');_x000D_
    },_x000D_
    function() {_x000D_
      $('#products-menu.dropdown-menu', this).stop( true, true ).fadeOut("fast");_x000D_
      $(this).toggleClass('open');_x000D_
    });_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<ul id="nav" class="nav nav-pills clearfix right" role="tablist">_x000D_
    <li><a href="#">menuA</a></li>_x000D_
    <li><a href="#">menuB</a></li>_x000D_
    <li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown">menuC</a>_x000D_
        <ul id="products-menu" class="dropdown-menu clearfix" role="menu">_x000D_
            <li><a href="">A</a></li>_x000D_
            <li><a href="">B</a></li>_x000D_
            <li><a href="">C</a></li>_x000D_
            <li><a href="">D</a></li>_x000D_
        </ul>_x000D_
    </li>_x000D_
    <li><a href="#">menuD</a></li>_x000D_
    <li><a href="#">menuE</a></li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

How to develop or migrate apps for iPhone 5 screen resolution?

I never faced such an issue with any device as I've had one codebase for all, without any hardcoded values. What I do is to have the maximum sized image as resource instead of one for each device. For example, I would have one for retina display and show it as aspect fit so it will be views as is on every device. Coming to deciding the frame of button, for instance, at run time. For this I use the % value of the patent view, example , if I want the width to be half of parent view take 50 % of parent and same applies for height and center.

With this I don't even need the xibs.

How do I move a table into a schema in T-SQL

Short answer:

ALTER SCHEMA new_schema TRANSFER old_schema.table_name

I can confirm that the data in the table remains intact, which is probably quite important :)

Long answer as per MSDN docs,

ALTER SCHEMA schema_name 
   TRANSFER [ Object | Type | XML Schema Collection ] securable_name [;]

If it's a table (or anything besides a Type or XML Schema collection), you can leave out the word Object since that's the default.

How to get a variable type in Typescript?

I'd like to add that TypeGuards only work on strings or numbers, if you want to compare an object use instanceof

if(task.id instanceof UUID) {
  //foo
}

How can I change the app display name build with Flutter?

There is a plugin, flutter_launcher_name.

Write file pubspec.yaml:

dev_dependencies:
  flutter_launcher_name: "^0.0.1"

flutter_launcher_name:
  name: "yourNewAppLauncherName"

And run:

flutter pub get
flutter pub run flutter_launcher_name:main

You can get the same result as editing AndroidManifes.xml and Info.plist.

Drop all the tables, stored procedures, triggers, constraints and all the dependencies in one sql statement

You have to disable all triggers and constraints first.

EXEC sp_MSforeachtable @command1="ALTER TABLE ? NOCHECK CONSTRAINT ALL"

EXEC sp_MSforeachtable @command1="ALTER TABLE ? DISABLE TRIGGER ALL"

After that you can generate the scripts for deleting the objects as

SELECT 'Drop Table '+name FROM sys.tables WHERE type='U';

SELECT 'Drop Procedure '+name FROM  sys.procedures WHERE type='P';

Execute the statements generated.

Expression must be a modifiable L-value

lvalue means "left value" -- it should be assignable. You cannot change the value of text since it is an array, not a pointer.

Either declare it as char pointer (in this case it's better to declare it as const char*):

const char *text;
if(number == 2) 
    text = "awesome"; 
else 
    text = "you fail";

Or use strcpy:

char text[60];
if(number == 2) 
    strcpy(text, "awesome"); 
else 
    strcpy(text, "you fail");

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;
        });

How to trim a string after a specific character in java

Try this:

String result = "34.1 -118.33\n<!--ABCDEFG-->";
result = result.substring(0, result.indexOf("\n"));

Linux: Which process is causing "device busy" when doing umount?

Open files

Processes with open files are the usual culprits. Display them:

lsof +f -- <mountpoint or device>

There is an advantage to using /dev/<device> rather than /mountpoint: a mountpoint will disappear after an umount -l, or it may be hidden by an overlaid mount.

fuser can also be used, but to my mind lsof has a more useful output. However fuser is useful when it comes to killing the processes causing your dramas so you can get on with your life.

List files on <mountpoint> (see caveat above):

fuser -vmM <mountpoint>

Interactively kill only processes with files open for writing:

fuser -vmMkiw <mountpoint>

After remounting read-only (mount -o remount,ro <mountpoint>), it is safe(r) to kill all remaining processes:

fuser -vmMk <mountpoint>

Mountpoints

The culprit can be the kernel itself. Another filesystem mounted on the filesystem you are trying to umount will cause grief. Check with:

mount | grep <mountpoint>/

For loopback mounts, also check the output of:

losetup -la

Anonymous inodes (Linux)

Anonymous inodes can be created by:

  • Temporary files (open with O_TMPFILE)
  • inotify watches
  • [eventfd]
  • [eventpoll]
  • [timerfd]

These are the most elusive type of pokemon, and appear in lsof's TYPE column as a_inode (which is undocumented in the lsof man page).

They won't appear in lsof +f -- /dev/<device>, so you'll need to:

lsof | grep a_inode

For killing processes holding anonymous inodes, see: List current inotify watches (pathname, PID).

Replace only text inside a div using jquery

Just in case if you can't change HTML. Very primitive but short & works. (It will empty the parent div hence the child divs will be removed)

_x000D_
_x000D_
$('#one').text('Hi I am replace');
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
<div id="one">_x000D_
  <div class="first"></div>_x000D_
  "Hi I am text"_x000D_
  <div class="second"></div>_x000D_
  <div class="third"></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Two dimensional array in python

You can first append elements to the initialized array and then for convenience, you can convert it into a numpy array.

import numpy as np
a = [] # declare null array
a.append(['aa1']) # append elements
a.append(['aa2'])
a.append(['aa3'])
print(a)
a_np = np.asarray(a) # convert to numpy array
print(a_np)

How to check if a table exists in MS Access for vb macros

Exists = IsObject(CurrentDb.TableDefs(tablename))

Confirm password validation in Angular 6

My answer is very simple>i have created password and confirm password validation using template driiven in angular 6

My html file

<div class="form-group">
  <label class="label-sm">Confirm Password</label>
  <input class="form-control" placeholder="Enter Password" type="password" #confirm_password="ngModel" [(ngModel)]="userModel.confirm_password" name="confirm_password" required (keyup)="checkPassword($event)" />
  <div *ngIf="confirm_password.errors && (confirm_password.dirty||confirm_password.touched||signup.submitted)">
  <div class="error" *ngIf="confirm_password.errors.required">Please confirm your password</div>
  </div>
  <div *ngIf="i" class='error'>Password does not match</div>
</div>

My typescript file

      public i: boolean;

      checkPassword(event) {
        const password = this.userModel.password;
        const confirm_new_password = event.target.value;

        if (password !== undefined) {
          if (confirm_new_password !== password) {
            this.i = true;
          } else {
            this.i = false;
          }
        }
      }

when clicking on submit button i check whether value of i is true or false

if true

if (this.i) {
      return false;
    }

else{
**form submitted code comes here**
}

Get first date of current month in java

try

    Calendar c = Calendar.getInstance();   // this takes current date
    c.set(Calendar.DAY_OF_MONTH, 1);
    System.out.println(c.getTime());       // this returns java.util.Date

Updated (Since Java 8):

import java.time.LocalDate;
LocalDate todaydate = LocalDate.now();
System.out.println("Months first date in yyyy-mm-dd: " +todaydate.withDayOfMonth(1));

Sequelize, convert entity to plain object

you can use the query options {raw: true} to return the raw result. Your query should like follows:

db.Sensors.findAll({
  where: {
    nodeid: node.nodeid
  },
  raw: true,
})

also if you have associations with include that gets flattened. So, we can use another parameter nest:true

db.Sensors.findAll({
  where: {
    nodeid: node.nodeid
  },
  raw: true,
  nest: true,
})

Convert a String to a byte array and then back to the original String

I would suggest using the members of string, but with an explicit encoding:

byte[] bytes = text.getBytes("UTF-8");
String text = new String(bytes, "UTF-8");

By using an explicit encoding (and one which supports all of Unicode) you avoid the problems of just calling text.getBytes() etc:

  • You're explicitly using a specific encoding, so you know which encoding to use later, rather than relying on the platform default.
  • You know it will support all of Unicode (as opposed to, say, ISO-Latin-1).

EDIT: Even though UTF-8 is the default encoding on Android, I'd definitely be explicit about this. For example, this question only says "in Java or Android" - so it's entirely possible that the code will end up being used on other platforms.

Basically given that the normal Java platform can have different default encodings, I think it's best to be absolutely explicit. I've seen way too many people using the default encoding and losing data to take that risk.

EDIT: In my haste I forgot to mention that you don't have to use the encoding's name - you can use a Charset instead. Using Guava I'd really use:

byte[] bytes = text.getBytes(Charsets.UTF_8);
String text = new String(bytes, Charsets.UTF_8);

Properly close mongoose's connection once you're done

Probably you have this:

const db = mongoose.connect('mongodb://localhost:27017/db');

// Do some stuff

db.disconnect();

but you can also have something like this:

mongoose.connect('mongodb://localhost:27017/db');

const model = mongoose.model('Model', ModelSchema);

model.find().then(doc => {
  console.log(doc);
}

you cannot call db.disconnect() but you can close the connection after you use it.

model.find().then(doc => {
  console.log(doc);
}).then(() => {
  mongoose.connection.close();
});

How to check if another instance of my shell script is running

An easier way to check for a process already executing is the pidof command.

if pidof -x "abc.sh" >/dev/null; then
    echo "Process already running"
fi

Alternatively, have your script create a PID file when it executes. It's then a simple exercise of checking for the presence of the PID file to determine if the process is already running.

#!/bin/bash
# abc.sh

mypidfile=/var/run/abc.sh.pid

# Could add check for existence of mypidfile here if interlock is
# needed in the shell script itself.

# Ensure PID file is removed on program exit.
trap "rm -f -- '$mypidfile'" EXIT

# Create a file with current PID to indicate that process is running.
echo $$ > "$mypidfile"

...

Update: The question has now changed to check from the script itself. In this case, we would expect to always see at least one abc.sh running. If there is more than one abc.sh, then we know that process is still running. I'd still suggest use of the pidof command which would return 2 PIDs if the process was already running. You could use grep to filter out the current PID, loop in the shell or even revert to just counting PIDs with wc to detect multiple processes.

Here's an example:

#!/bin/bash

for pid in $(pidof -x abc.sh); do
    if [ $pid != $$ ]; then
        echo "[$(date)] : abc.sh : Process is already running with PID $pid"
        exit 1
    fi
done

How to do multiple conditions for single If statement

As Hogan notes above, use an AND instead of &. See this tutorial for more info.

Using jQuery to programmatically click an <a> link

I tried few of the above solutions but they didn't worked for me. Here is a link to the page which worked for me automatically click a link

Above link has many solutions and here's the one which worked for me,

    <button onclick="fun();">Magic button</button>

    <!--The link you want to automatically click-->
    <a href='http://www.ercafe.com' id="myAnchor">My website</a>

Now within the <script> tags,

<script>

     function fun(){
          actuateLink(document.getElementById('myAnchor'));
     }

     function actuateLink(link)
     {
          var allowDefaultAction = true;

          if (link.click)
          {
              link.click();
              return;
          }
          else if (document.createEvent)
          {
              var e = document.createEvent('MouseEvents');
              e.initEvent(
                   'click'     // event type
                   ,true      // can bubble?
                   ,true      // cancelable?
              );
              allowDefaultAction = link.dispatchEvent(e);           
          }

          if (allowDefaultAction)       
          {
              var f = document.createElement('form');
              f.action = link.href;
              document.body.appendChild(f);
              f.submit();
          }
    }

</script>

Copy paste the above code and click on clicking the 'Magic button' button, you will be redirected to ErCafe.com.

nginx error connect to php5-fpm.sock failed (13: Permission denied)

Just see /etc/php5/php-fpm.conf pid = /var/run/php5-fpm.pid IS PID file

In file /etc/php5/fpm/pool.d/www.conf

listen = /var/run/php5-fpm.sock IS SOCKET file

if you pid equal listen (pid = /var/run/php5-fpm.sock and listen = /var/run/php5-fpm.sock) -> wrong settings and finish sett /etc/php5/fpm/pool.d/www.conf

user = nginx
group = nginx
listen.owner = nginx
listen.group = nginx
listen.mode = 0660

Fatal error: [] operator not supported for strings

I agree with Jeremy Young's comment on Phils answer:

I have found that this can be a problem associated with migrating from php 5 to php 7. php 5 was more tolerant of amibiguity in whether a variable was an array or not than php 7 is. In most cases the solution is to declare the array explicitly, as explained in this answer.

I was just trouble shooting a Wordpress plugin after the migration of php5 to php7. Since the plugin code was relying on user input, and it was intrinsically used in the code either as string, or as array, I added the following code in to prevent a fatal error:

if(is_array($variable_either_string_or_array)){
    // if it's an array, declaration is allowed:
    $variable_either_string_or_array[]=$additionalInfoData[$i];
}else{
    // if it's not an array, declaration it as follows:
    $variable_either_string_or_array=$additionalInfoData[$i];
}

This was the only modification I needed to add to make the plugin php7-proof. Obviously not "best practices", I'd rather read and understand the full code.. but a quick fix was needed.

super() in Java

The super keyword can be used to call the superclass constructor and to refer to a member of the superclass

When you call super() with the right arguments, we actually call the constructor Box, which initializes variables width, height and depth, referred to it by using the values of the corresponding parameters. You only remains to initialize its value added weight. If necessary, you can do now class variables Box as private. Put down in the fields of the Box class private modifier and make sure that you can access them without any problems.

At the superclass can be several overloaded versions constructors, so you can call the method super() with different parameters. The program will perform the constructor that matches the specified arguments.

public class Box {

    int width;
    int height;
    int depth;

    Box(int w, int h, int d) {
        width = w;
        height = h;
        depth = d;
    }

    public static void main(String[] args){
        HeavyBox heavy = new HeavyBox(12, 32, 23, 13);
    }

}

class HeavyBox extends Box {

    int weight;

    HeavyBox(int w, int h, int d, int m) {

        //call the superclass constructor
        super(w, h, d);
        weight = m;
    }

}

How do I get the HTTP status code with jQuery?

I have had major issues with ajax + jQuery v3 getting both the response status code and data from JSON APIs. jQuery.ajax only decodes JSON data if the status is a successful one, and it also swaps around the ordering of the callback parameters depending on the status code. Ugghhh.

The best way to combat this is to call the .always chain method and do a bit of cleaning up. Here is my code.

$.ajax({
        ...
    }).always(function(data, textStatus, xhr) {
        var responseCode = null;
        if (textStatus === "error") {
            // data variable is actually xhr
            responseCode = data.status;
            if (data.responseText) {
                try {
                    data = JSON.parse(data.responseText);
                } catch (e) {
                    // Ignore
                }
            }
        } else {
            responseCode = xhr.status;
        }

        console.log("Response code", responseCode);
        console.log("JSON Data", data);
    });

macro - open all files in a folder

Try the below code:

Sub opendfiles()

Dim myfile As Variant
Dim counter As Integer
Dim path As String

myfolder = "D:\temp\"
ChDir myfolder
myfile = Application.GetOpenFilename(, , , , True)
counter = 1
If IsNumeric(myfile) = True Then
    MsgBox "No files selected"
End If
While counter <= UBound(myfile)
    path = myfile(counter)
    Workbooks.Open path
    counter = counter + 1
Wend

End Sub

How to solve error: "Clock skew detected"?

please try to do

make clean

(instead of make), then

make

again.

Limit results in jQuery UI Autocomplete

You can set the minlength option to some big value or you can do it by css like this,

.ui-autocomplete { height: 200px; overflow-y: scroll; overflow-x: hidden;}

.NET HashTable Vs Dictionary - Can the Dictionary be as fast?

Dictionary is faster than hashtable as dictionary is a generic strong type. Hashtable is slower as it takes object as data type which leads to boxing and unboxing.

How do I dynamically change the content in an iframe using jquery?

var handle = setInterval(changeIframe, 30000);
var sites = ["google.com", "yahoo.com"];
var index = 0;

function changeIframe() {
  $('#frame')[0].src = sites[index++];
  index = index >= sites.length ? 0 : index;
}

Flask - Calling python function on button OnClick event

It sounds like you want to use this web application as a remote control for your robot, and a core issue is that you won't want a page reload every time you perform an action, in which case, the last link you posted answers your problem.

I think you may be misunderstanding a few things about Flask. For one, you can't nest multiple functions in a single route. You're not making a set of functions available for a particular route, you're defining the one specific thing the server will do when that route is called.

With that in mind, you would be able to solve your problem with a page reload by changing your app.py to look more like this:

from flask import Flask, render_template, Response, request, redirect, url_for
app = Flask(__name__)

@app.route("/")
def index():
    return render_template('index.html')

@app.route("/forward/", methods=['POST'])
def move_forward():
    #Moving forward code
    forward_message = "Moving Forward..."
    return render_template('index.html', forward_message=forward_message);

Then in your html, use this:

<form action="/forward/" method="post">
    <button name="forwardBtn" type="submit">Forward</button>
</form>

...To execute your moving forward code. And include this:

{{ forward_message }} 

... where you want the moving forward message to appear on your template.

This will cause your page to reload, which is inevitable without using AJAX and Javascript.

Java AES and using my own Key

Edit:

As written in the comments the old code is not "best practice". You should use a keygeneration algorithm like PBKDF2 with a high iteration count. You also should use at least partly a non static (meaning for each "identity" exclusive) salt. If possible randomly generated and stored together with the ciphertext.

    SecureRandom sr = SecureRandom.getInstanceStrong();
    byte[] salt = new byte[16];
    sr.nextBytes(salt);

    PBEKeySpec spec = new PBEKeySpec(password.toCharArray(), salt, 1000, 128 * 8);
    SecretKey key = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1").generateSecret(spec);
    Cipher aes = Cipher.getInstance("AES");
    aes.init(Cipher.ENCRYPT_MODE, key);

===========

Old Answer

You should use SHA-1 to generate a hash from your key and trim the result to 128 bit (16 bytes).

Additionally don't generate byte arrays from Strings through getBytes() it uses the platform default Charset. So the password "blaöä" results in different byte array on different platforms.

byte[] key = (SALT2 + username + password).getBytes("UTF-8");
MessageDigest sha = MessageDigest.getInstance("SHA-1");
key = sha.digest(key);
key = Arrays.copyOf(key, 16); // use only first 128 bit

SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");

Edit: If you need 256 bit as key sizes you need to download the "Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files" Oracle download link, use SHA-256 as hash and remove the Arrays.copyOf line. "ECB" is the default Cipher Mode and "PKCS5Padding" the default padding. You could use different Cipher Modes and Padding Modes through the Cipher.getInstance string using following format: "Cipher/Mode/Padding"

For AES using CTS and PKCS5Padding the string is: "AES/CTS/PKCS5Padding"

Regular Expression to find a string included between two characters while EXCLUDING the delimiters

You just need to 'capture' the bit between the brackets.

\[(.*?)\]

To capture you put it inside parentheses. You do not say which language this is using. In Perl for example, you would access this using the $1 variable.

my $string ='This is the match [more or less]';
$string =~ /\[(.*?)\]/;
print "match:$1\n";

Other languages will have different mechanisms. C#, for example, uses the Match collection class, I believe.

Pass entire form as data in jQuery Ajax function

In general use serialize() on the form element.

Please be mindful that multiple <select> options are serialized under the same key, e.g.

<select id="foo" name="foo" multiple="multiple">
    <option value="1">one</option>
    <option value="2">two</option>
    <option value="3">three</option>
</select>

will result in a query string that includes multiple occurences of the same query parameter:

[path]?foo=1&foo=2&foo=3&someotherparams...

which may not be what you want in the backend.

I use this JS code to reduce multiple parameters to a comma-separated single key (shamelessly copied from a commenter's response in a thread over at John Resig's place):

function compress(data) {
    data = data.replace(/([^&=]+=)([^&]*)(.*?)&\1([^&]*)/g, "$1$2,$4$3");
    return /([^&=]+=).*?&\1/.test(data) ? compress(data) : data;
}

which turns the above into:

[path]?foo=1,2,3&someotherparams...

In your JS code you'd call it like this:

var inputs = compress($("#your-form").serialize());

Hope that helps.

Case statement with multiple values in each 'when' block

Another nice way to put your logic in data is something like this:

# Initialization.
CAR_TYPES = {
  foo_type: ['honda', 'acura', 'mercedes'],
  bar_type: ['toyota', 'lexus']
  # More...
}
@type_for_name = {}
CAR_TYPES.each { |type, names| names.each { |name| @type_for_name[type] = name } }

case @type_for_name[car]
when :foo_type
  # do foo things
when :bar_type
  # do bar things
end

Pythonic way to find maximum value and its index in a list?

I would suggest a very simple way:

import numpy as np
l = [10, 22, 8, 8, 11]
print(np.argmax(l))
print(np.argmin(l))

Hope it helps.

How to pass multiple values through command argument in Asp.net?

You can try this:

CommandArgument='<%# "scrapid=" + Eval("ScrapId")+"&"+"UserId="+ Eval("UserId")%>'

Make file echo displaying "$PATH" string

The make uses the $ for its own variable expansions. E.g. single character variable $A or variable with a long name - ${VAR} and $(VAR).

To put the $ into a command, use the $$, for example:

all:
  @echo "Please execute next commands:"
  @echo 'setenv PATH /usr/local/greenhills/mips5/linux86:$$PATH'

Also note that to make the "" and '' (double and single quoting) do not play any role and they are passed verbatim to the shell. (Remove the @ sign to see what make sends to shell.) To prevent the shell from expanding $PATH, second line uses the ''.

How to disable scientific notation?

You can effectively remove scientific notation in printing with this code:

options(scipen=999)

How do I turn off the mysql password validation?

Here is what I do to remove the validate password plugin:

  1. Login to the mysql server as root mysql -h localhost -u root -p
  2. Run the following sql command: uninstall plugin validate_password;
  3. If last line doesn't work (new mysql release), you should execute UNINSTALL COMPONENT 'file://component_validate_password';

I would not recommend this solution for a production system. I used this solution on a local mysql instance for development purposes only.

How to pass multiple parameters in thread in VB

Just create a class or structure that has two members, one List(Of OneItem) and the other Integer and send in an instance of that class.

Edit: Sorry, missed that you had problems with one parameter as well. Just look at Thread Constructor (ParameterizedThreadStart) and that page includes a simple sample.

How to specify Memory & CPU limit in docker compose version 3

deploy:
  resources:
    limits:
      cpus: '0.001'
      memory: 50M
    reservations:
      cpus: '0.0001'
      memory: 20M

More: https://docs.docker.com/compose/compose-file/compose-file-v3/#resources

In you specific case:

version: "3"
services:
  node:
    image: USER/Your-Pre-Built-Image
    environment:
      - VIRTUAL_HOST=localhost
    volumes:
      - logs:/app/out/
    command: ["npm","start"]
    cap_drop:
      - NET_ADMIN
      - SYS_ADMIN
    deploy:
      resources:
        limits:
          cpus: '0.001'
          memory: 50M
        reservations:
          cpus: '0.0001'
          memory: 20M

volumes:
  - logs

networks:
  default:
    driver: overlay

Note:

  • Expose is not necessary, it will be exposed per default on your stack network.
  • Images have to be pre-built. Build within v3 is not possible
  • "Restart" is also deprecated. You can use restart under deploy with on-failure action
  • You can use a standalone one node "swarm", v3 most improvements (if not all) are for swarm

Also Note: Networks in Swarm mode do not bridge. If you would like to connect internally only, you have to attach to the network. You can 1) specify an external network within an other compose file, or have to create the network with --attachable parameter (docker network create -d overlay My-Network --attachable) Otherwise you have to publish the port like this:

ports:
  - 80:80

Return a "NULL" object if search result not found

You can easily create a static object that represents a NULL return.

class Attr;
extern Attr AttrNull;

class Node { 
.... 

Attr& getAttribute(const string& attribute_name) const { 
   //search collection 
   //if found at i 
        return attributes[i]; 
   //if not found 
        return AttrNull; 
} 

bool IsNull(const Attr& test) const {
    return &test == &AttrNull;
}

 private: 
   vector<Attr> attributes; 
};

And somewhere in a source file:

static Attr AttrNull;

Prevent line-break of span element

If you only need to prevent line-breaks on space characters, you can use &nbsp; entities between words:

No&nbsp;line&nbsp;break

instead of

<span style="white-space:nowrap">No line break</span>

Allow anonymous authentication for a single folder in web.config?

<location path="ForAll/Demo.aspx">
 <system.web>
  <authorization>
    <allow users="*" />
  </authorization>
 </system.web>
</location>

In Addition: If you want to write something on that folder through website , you have to give IIS_User permission to the folder

javac error: Class names are only accepted if annotation processing is explicitly requested

You at least need to add the .java extension to the file name in this line:

javac -cp /home/manish.yadav/Desktop/JCuda-All-0.3.2-bin-linux-x86_64 EnumDevices

From the official faq:

Class names, 'HelloWorldApp', are only accepted if annotation processing is explicitly requested

If you receive this error, you forgot to include the .java suffix when compiling the program. Remember, the command is javac HelloWorldApp.java not javac HelloWorldApp.

Also, in your second javac-example, (in which you actually included .java) you need to include the all required .jar-files needed for compilation.

VBA copy cells value and format

Following on from jpw it might be good to encapsulate his solution in a small subroutine to save on having lots of lines of code:

Private Sub CommandButton1_Click()
Dim i As Integer
Dim a As Integer
a = 15
For i = 11 To 32
  If Worksheets(1).Cells(i, 3) <> "" Then
    call copValuesAndFormat(i,3,a,15)        
    call copValuesAndFormat(i,5,a,17) 
    call copValuesAndFormat(i,6,a,18) 
    call copValuesAndFormat(i,7,a,19) 
    call copValuesAndFormat(i,8,a,20) 
    call copValuesAndFormat(i,9,a,21) 
    a = a + 1
  End If
Next i
end sub

sub copValuesAndFormat(x1 as integer, y1 as integer, x2 as integer, y2 as integer)
  Worksheets(1).Cells(x1, y1).Copy
  Worksheets(2).Cells(x2, y2).PasteSpecial Paste:=xlPasteFormats
  Worksheets(2).Cells(x2, y2).PasteSpecial Paste:=xlPasteValues
end sub

(I do not have Excel in current location so please excuse bugs as not tested)

How to remove &quot; from my Json in javascript?

The following works for me:

function decodeHtml(html) {
    let areaElement = document.createElement("textarea");
    areaElement.innerHTML = html;

    return areaElement.value;
}

Reading specific columns from a text file in python

f=open(file,"r")
lines=f.readlines()
result=[]
for x in lines:
    result.append(x.split(' ')[1])
f.close()

You can do the same using a list comprehension

print([x.split(' ')[1] for x in open(file).readlines()])

Docs on split()

string.split(s[, sep[, maxsplit]])

Return a list of the words of the string s. If the optional second argument sep is absent or None, the words are separated by arbitrary strings of whitespace characters (space, tab, newline, return, formfeed). If the second argument sep is present and not None, it specifies a string to be used as the word separator. The returned list will then have one more item than the number of non-overlapping occurrences of the separator in the string.

So, you can omit the space I used and do just x.split() but this will also remove tabs and newlines, be aware of that.

How would you make two <div>s overlap?

Using CSS, you set the logo div to position absolute, and set the z-order to be above the second div.

#logo
{
    position: absolute:
    z-index: 2000;
    left: 100px;
    width: 100px;
    height: 50px;
}

Bad File Descriptor with Linux Socket write() Bad File Descriptor C

I had this error too, my problem was in some part of code I didn't close file descriptor and in other part, I tried to open that file!! use close(fd) system call after you finished working on a file.

jQuery find file extension (from string)

var fileName = 'file.txt';

// Getting Extension

var ext = fileName.split('.')[1];

// OR

var ext = fileName.split('.').pop();

How to check if a string in Python is in ASCII?

How about doing this?

import string

def isAscii(s):
    for c in s:
        if c not in string.ascii_letters:
            return False
    return True

ArrayAdapter in android to create simple listview

But again main doubt why TextView resource id it needs?

Look at the constructor and the params.

public ArrayAdapter (Context context, int resource, int textViewResourceId, T[] objects)

Added in API level 1 Constructor

Parameters

context The current context.

resource The resource ID for a layout file containing a layout to use when instantiating views.

textViewResourceId The id of the TextView within the layout resource to be populated objects The objects to represent in the ListView.

android.R.id.text1 refers to the id of text in android resource. So you need not have the one in your activity.

Here's the full list

http://developer.android.com/reference/android/R.id.html

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
        android.R.layout.simple_list_item_1, android.R.id.text1, values);

this refers to activity context

android.R.layout.simple_list_item_1 simple_list_item_1 is the layout in android.R.layout.

android.R.id.text1 refers to the android resource id.

values is a string array from the link you provided

http://developer.android.com/reference/android/R.layout.html

Where is the IIS Express configuration / metabase file found?

To come full circle and include all versions of Visual Studio, @Myster originally stated that;

Pre Visual Studio 2015 the paths to applicationhost.config were:

%userprofile%\documents\iisexpress\config\applicationhost.config
%userprofile%\my documents\iisexpress\config\applicationhost.config

Visual Studio 2015/2017 path can be found at: (credit: @Talon)

$(solutionDir)\.vs\config\applicationhost.config

Visual Studio 2019 path can be found at: (credit: @Talon)

$(solutionDir)\.vs\config\$(ProjectName)\applicationhost.config

But the part that might get some people is that the project settings in the .sln file can repopulate the applicationhost.config for Visual Studio 2015+. (credit: @Lex Li)

So, if you make a change in the applicationhost.config you also have to make sure your changes match here:

$(solutionDir)\ProjectName.sln

The two important settings should look like:

Project("{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}") = "ProjectName", "ProjectPath\", "{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}"

and

VWDPort = "Port#"

What is important here is that the two settings in the .sln must match the name and bindingInformation respectively in the applicationhost.config file if you plan on making changes. There may be more places that link these two files and I will update as I find more links either by comments or more experience.

How to select clear table contents without destroying the table?

I use this code to remove my data but leave the formulas in the top row. It also removes all rows except for the top row and scrolls the page up to the top.

Sub CleanTheTable()
    Application.ScreenUpdating = False
    Sheets("Data").Select
    ActiveSheet.ListObjects("TestTable").HeaderRowRange.Select
    'Remove the filters if one exists.
    If ActiveSheet.FilterMode Then
    Selection.AutoFilter
    End If
    'Clear all lines but the first one in the table leaving formulas for the next go round.
    With Worksheets("Data").ListObjects("TestTable")
    .Range.AutoFilter
    On Error Resume Next
    .DataBodyRange.Offset(1).Resize(.DataBodyRange.Rows.Count - 1, .DataBodyRange.Columns.Count).Rows.Delete
    .DataBodyRange.Rows(1).SpecialCells(xlCellTypeConstants).ClearContents
    ActiveWindow.SmallScroll Down:=-10000

    End With
Application.ScreenUpdating = True
End Sub

How to write a test which expects an Error to be thrown in Jasmine?

For coffeescript lovers

expect( => someMethodCall(arg1, arg2)).toThrow()

How do you create a remote Git branch?

As stated in the previous answers,

git push <remote-name> <local-branch-name>:<remote-branch-name>

is enough for pushing a local branch.

Your colleagues, can pull all remote branches (including new ones) with this command:

git remote update

Then, to make changes on the branch, the usual flow:

git checkout -b <local-branch-name> <remote-name>/<remote-branch-name>

How to avoid 'cannot read property of undefined' errors?

If you have lodash you can use its .get method

_.get(a, 'b.c.d.e')

or give it a default value

_.get(a, 'b.c.d.e', default)

How to call Oracle MD5 hash function?

In Oracle 12c you can use the function STANDARD_HASH. It does not require any additional privileges.

select standard_hash('foo', 'MD5') from dual;

The dbms_obfuscation_toolkit is deprecated (see Note here). You can use DBMS_CRYPTO directly:

select rawtohex(
    DBMS_CRYPTO.Hash (
        UTL_I18N.STRING_TO_RAW ('foo', 'AL32UTF8'),
        2)
    ) from dual;

Output:

ACBD18DB4CC2F85CEDEF654FCCC4A4D8

Add a lower function call if needed. More on DBMS_CRYPTO.

String concatenation in MySQL

Use concat() function instead of + like this:

select concat(firstname, lastname) as "Name" from test.student

How to print HTML content on click of a button, but not the page?

Below Code May Be Help You :

<html>
<head>
<script>
function printPage(id)
{
   var html="<html>";
   html+= document.getElementById(id).innerHTML;

   html+="</html>";

   var printWin = window.open('','','left=0,top=0,width=1,height=1,toolbar=0,scrollbars=0,status  =0');
   printWin.document.write(html);
   printWin.document.close();
   printWin.focus();
   printWin.print();
   printWin.close();
}
</script>
</head>
<body>
<div id="block1">
<table border="1" >
</tr>
<th colspan="3">Block 1</th>
</tr>
<tr>
<th>1</th><th>XYZ</th><th>athock</th>
</tr>
</table>

</div>

<div id="block2">
    This is Block 2 content
</div>

<input type="button" value="Print Block 1" onclick="printPage('block1');"></input>
<input type="button" value="Print Block 2" onclick="printPage('block2');"></input>
</body>
</html>

How do I get the month and day with leading 0's in SQL? (e.g. 9 => 09)

For SQL Server 2012 and up , with leading zeroes:

 SELECT FORMAT(GETDATE(),'MM') 

without:

SELECT    MONTH(GETDATE())

What's the proper way to compare a String to an enum value?

Doing an static import of the GestureTypes and then using the valuesOf() method could make it look much cleaner:

enum GestureTypes{ROCK,PAPER,SCISSORS};

and

import static com.example.GestureTypes.*;
public class GestureFactory {

    public static Gesture getInstance(final String gesture) {
        if (ROCK == valueOf(gesture))
            //do somthing
        if (PAPER == valueOf(gesture))
            //do somthing
    }
}

Parser Error when deploy ASP.NET application

In my case, There were new code branch and old code branch was deployed locally in IIS. So it was pointing to old branch code that was not available. So i had deployed my code to IIS with new branch and it is working now.

Transition of background-color

To me, it is better to put the transition codes with the original/minimum selectors than with the :hover or any other additional selectors:

_x000D_
_x000D_
#content #nav a {_x000D_
    background-color: #FF0;_x000D_
    _x000D_
    -webkit-transition: background-color 1000ms linear;_x000D_
    -moz-transition: background-color 1000ms linear;_x000D_
    -o-transition: background-color 1000ms linear;_x000D_
    -ms-transition: background-color 1000ms linear;_x000D_
    transition: background-color 1000ms linear;_x000D_
}_x000D_
_x000D_
#content #nav a:hover {_x000D_
    background-color: #AD310B;_x000D_
}
_x000D_
<div id="content">_x000D_
    <div id="nav">_x000D_
        <a href="#link1">Link 1</a>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Dump a NumPy array into a csv file

numpy.savetxt saves an array to a text file.

import numpy
a = numpy.asarray([ [1,2,3], [4,5,6], [7,8,9] ])
numpy.savetxt("foo.csv", a, delimiter=",")

Paritition array into N chunks with Numpy

Try numpy.array_split.

From the documentation:

>>> x = np.arange(8.0)
>>> np.array_split(x, 3)
    [array([ 0.,  1.,  2.]), array([ 3.,  4.,  5.]), array([ 6.,  7.])]

Identical to numpy.split, but won't raise an exception if the groups aren't equal length.

If number of chunks > len(array) you get blank arrays nested inside, to address that - if your split array is saved in a, then you can remove empty arrays by:

[x for x in a if x.size > 0]

Just save that back in a if you wish.

C-like structures in Python

I wrote a decorator which you can use on any method to make it so that all of the arguments passed in, or any defaults, are assigned to the instance.

def argumentsToAttributes(method):
    argumentNames = method.func_code.co_varnames[1:]

    # Generate a dictionary of default values:
    defaultsDict = {}
    defaults = method.func_defaults if method.func_defaults else ()
    for i, default in enumerate(defaults, start = len(argumentNames) - len(defaults)):
        defaultsDict[argumentNames[i]] = default

    def newMethod(self, *args, **kwargs):
        # Use the positional arguments.
        for name, value in zip(argumentNames, args):
            setattr(self, name, value)

        # Add the key word arguments. If anything is missing, use the default.
        for name in argumentNames[len(args):]:
            setattr(self, name, kwargs.get(name, defaultsDict[name]))

        # Run whatever else the method needs to do.
        method(self, *args, **kwargs)

    return newMethod

A quick demonstration. Note that I use a positional argument a, use the default value for b, and a named argument c. I then print all 3 referencing self, to show that they've been properly assigned before the method is entered.

class A(object):
    @argumentsToAttributes
    def __init__(self, a, b = 'Invisible', c = 'Hello'):
        print(self.a)
        print(self.b)
        print(self.c)

A('Why', c = 'Nothing')

Note that my decorator should work with any method, not just __init__.

Using headers with the Python requests library's get method

According to the API, the headers can all be passed in using requests.get:

import requests
r=requests.get("http://www.example.com/", headers={"content-type":"text"})

How to search in a List of Java object

You can give a try to Apache Commons Collections.

There is a class CollectionUtils that allows you to select or filter items by custom Predicate.

Your code would be like this:

Predicate condition = new Predicate() {
   boolean evaluate(Object sample) {
        return ((Sample)sample).value3.equals("three");
   }
};
List result = CollectionUtils.select( list, condition );

Update:

In java8, using Lambdas and StreamAPI this should be:

List<Sample> result = list.stream()
     .filter(item -> item.value3.equals("three"))
     .collect(Collectors.toList());

much nicer!

Split value from one field to two

If your plan is to do this as part of a query, please don't do that (a). Seriously, it's a performance killer. There may be situations where you don't care about performance (such as one-off migration jobs to split the fields allowing better performance in future) but, if you're doing this regularly for anything other than a mickey-mouse database, you're wasting resources.

If you ever find yourself having to process only part of a column in some way, your DB design is flawed. It may well work okay on a home address book or recipe application or any of myriad other small databases but it will not be scalable to "real" systems.

Store the components of the name in separate columns. It's almost invariably a lot faster to join columns together with a simple concatenation (when you need the full name) than it is to split them apart with a character search.

If, for some reason you cannot split the field, at least put in the extra columns and use an insert/update trigger to populate them. While not 3NF, this will guarantee that the data is still consistent and will massively speed up your queries. You could also ensure that the extra columns are lower-cased (and indexed if you're searching on them) at the same time so as to not have to fiddle around with case issues.

And, if you cannot even add the columns and triggers, be aware (and make your client aware, if it's for a client) that it is not scalable.


(a) Of course, if your intent is to use this query to fix the schema so that the names are placed into separate columns in the table rather than the query, I'd consider that to be a valid use. But I reiterate, doing it in the query is not really a good idea.

Stretch and scale CSS background

This is what I've made of it. In the stretch class, I simply changed the height to auto. This way your background picture has always got the same size as the width of the screen and the height will allways have the right size.

#background {
    width: 100%;
    height: 100%;
    position: absolute;
    margin-left: 0px;
    margin-top: 0px;
    z-index: 0;
}

.stretch {
    width:100%;
    height:auto;
}

What is the pythonic way to unpack tuples?

Generally, you can use the func(*tuple) syntax. You can even pass a part of the tuple, which seems like what you're trying to do here:

t = (2010, 10, 2, 11, 4, 0, 2, 41, 0)
dt = datetime.datetime(*t[0:7])

This is called unpacking a tuple, and can be used for other iterables (such as lists) too. Here's another example (from the Python tutorial):

>>> range(3, 6)             # normal call with separate arguments
[3, 4, 5]
>>> args = [3, 6]
>>> range(*args)            # call with arguments unpacked from a list
[3, 4, 5]

How to check if a string starts with a specified string?

PHP 8 or newer:

Use the str_starts_with function:

str_starts_with('http://www.google.com', 'http')

PHP 7 or older:

Use the substr function to return a part of a string.

substr( $string_n, 0, 4 ) === "http"

If you're trying to make sure it's not another protocol. I'd use http:// instead, since https would also match, and other things such as http-protocol.com.

substr( $string_n, 0, 7 ) === "http://"

And in general:

substr($string, 0, strlen($query)) === $query

How to close form

You need the actual instance of the WindowSettings that's open, not a new one.

Currently, you are creating a new instance of WindowSettings and calling Close on that. That doesn't do anything because that new instance never has been shown.

Instead, when showing DialogSettingsCancel set the current instance of WindowSettings as the parent.

Something like this:

In WindowSettings:

private void showDialogSettings_Click(object sender, EventArgs e)
{
    var dialogSettingsCancel = new DialogSettingsCancel();
    dialogSettingsCancel.OwningWindowSettings = this;
    dialogSettingsCancel.Show();
}

In DialogSettingsCancel:

public WindowSettings OwningWindowSettings { get; set; }

private void button1_Click(object sender, EventArgs e)
{
    this.Close();
    if(OwningWindowSettings != null)
        OwningWindowSettings.Close();
}

This approach takes into account, that a DialogSettingsCancel could potentially be opened without a WindowsSettings as parent.

If the two are always connected, you should instead use a constructor parameter:

In WindowSettings:

private void showDialogSettings_Click(object sender, EventArgs e)
{
    var dialogSettingsCancel = new DialogSettingsCancel(this);
    dialogSettingsCancel.Show();
}

In DialogSettingsCancel:

WindowSettings _owningWindowSettings;

public DialogSettingsCancel(WindowSettings owningWindowSettings)
{
    if(owningWindowSettings == null)
        throw new ArgumentNullException("owningWindowSettings");

    _owningWindowSettings = owningWindowSettings;
}

private void button1_Click(object sender, EventArgs e)
{
    this.Close();
    _owningWindowSettings.Close();
}

Maven: best way of linking custom external JAR to my project?

You can create an In Project Repository, so you don't have to run mvn install:install-file every time you work on a new computer

<repository>
    <id>in-project</id>
    <name>In Project Repo</name>
    <url>file://${project.basedir}/libs</url>
</repository>

<dependency>
    <groupId>dropbox</groupId>
    <artifactId>dropbox-sdk</artifactId>
    <version>1.3.1</version>
</dependency>

/groupId/artifactId/version/artifactId-verion.jar

detail read this blog post

https://web.archive.org/web/20121026021311/charlie.cu.cc/2012/06/how-add-external-libraries-maven

how to access iFrame parent page using jquery?

in parent window put :

<script>
function ifDoneChildFrame(val)
{
   $('#parentPrice').html(val);
}
</script>

and in iframe src file put :

<script>window.parent.ifDoneChildFrame('Your value here');</script>

How to force reloading php.ini file?

To force a reload of the php.ini you should restart apache.

Try sudo service apache2 restart from the command line. Or sudo /etc/init.d/apache2 restart

GSON - Date format

You can specify you format Gson gson = builder.setDateFormat("yyyy-MM-dd").create(); in this method instead of yyyy-MM-dd you can use anyother formats

 GsonBuilder builder = new GsonBuilder();
                        builder.registerTypeAdapter(Date.class, new JsonDeserializer<Date>() {
                            public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
                                return new Date(json.getAsJsonPrimitive().getAsLong());
                            }
                        });

                        Gson gson = builder.setDateFormat("yyyy-MM-dd").create();

PHP server on local machine?

Install XAMPP. If you're running MS Windows, WAMP is also an option.

How to remove duplicate objects in a List<MyObject> without equals/hashcode?

Create a new class that wraps your Blog object and provides the equality/hashcode method you need. For maximum efficiency I would add two static methods on the wrapper, one to convert Blogs list -> Blog Wrapper list and the other to convert Blog Wrapper list -> Blog list. Then you would:

  1. Convert your blog list to blog wrapper list
  2. Add your blog wrapper list to a Hash Set
  3. Get the condensed blog wrapper list back out of the Hash Set
  4. Convert the blog wrapper list to a blog list

Code for Blog Wrapper would be something like this:

import java.util.ArrayList;
import java.util.List;

public class BlogWrapper {
    public static List<Blog> unwrappedList(List<BlogWrapper> blogWrapperList) {
        if (blogWrapperList == null)
            return new ArrayList<Blog>(0);

        List<Blog> blogList = new ArrayList<Blog>(blogWrapperList.size());
        for (BlogWrapper bW : blogWrapperList) {
            blogList.add(bW.getBlog());
        }

        return blogList;
    }

    public static List<BlogWrapper> wrappedList(List<Blog> blogList) {
        if (blogList == null)
            return new ArrayList<BlogWrapper>(0);

        List<BlogWrapper> blogWrapperList = new ArrayList<BlogWrapper>(blogList
                .size());
        for (Blog b : blogList) {
            blogWrapperList.add(new BlogWrapper(b));
        }

        return blogWrapperList;
    }

    private Blog blog = null;

    public BlogWrapper() {
        super();
    }

    public BlogWrapper(Blog aBlog) {
        super();
        setBlog(aBlog);
    }

    public boolean equals(Object other) {
        // Your equality logic here
        return super.equals(other);
    }

    public Blog getBlog() {
        return blog;
    }

    public int hashCode() {
        // Your hashcode logic here
        return super.hashCode();
    }

    public void setBlog(Blog blog) {
        this.blog = blog;
    }
}

And you could use this like so:

List<BlogWrapper> myBlogWrappers = BlogWrapper.wrappedList(your blog list here);
Set<BlogWrapper> noDupWrapSet = new HashSet<BlogWrapper>(myBlogWrappers);
List<BlogWrapper> noDupWrapList = new ArrayList<BlogWrapper>(noDupSet);
List<Blog> noDupList = BlogWrapper.unwrappedList(noDupWrapList);

Quite obviously you can make the above code more efficient, particularly by making the wrap and unwrap methods on Blog Wrapper take collections instead of Lists.

An alternative route to wrapping the Blog class would be to use a byte code manipulation library like BCEL to actually change the equals and hashcode method for Blog. But of course, that could have unintended consequences to the rest of your code if they require the original equals/hashcode behaviour.

How to stop/terminate a python script from running?

Windows solution: Control + C.

Macbook solution: Control (^) + C.

Another way is to open a terminal, type top, write down the PID of the process that you would like to kill and then type on the terminal: kill -9 <pid>

Intercept and override HTTP requests from WebView

You don't mention the API version, but since API 11 there's the method WebViewClient.shouldInterceptRequest

Maybe this could help?

Set date input field's max date to today

Yes, and no. There are min and max attributes in HTML 5, but

The max attribute will not work for dates and time in Internet Explorer 10+ or Firefox, since IE 10+ and Firefox does not support these input types.

EDIT: Firefox now does support it

So if you are confused by the documentation of that attributes, yet it doesn't work, that's why.
See the W3 page for the versions.

I find it easiest to use Javascript, s the other answers say, since you can just use a pre-made module. Also, many Javascript date picker libraries have a min/max setting and have that nice calendar look.

How to trim a string in SQL Server before 2017?

SELECT LTRIM(RTRIM(Names)) AS Names FROM Customer

What is the best way to dump entire objects to a log in C#?

I'm certain there are better ways of doing this, but I have in the past used a method something like the following to serialize an object into a string that I can log:

  private string ObjectToXml(object output)
  {
     string objectAsXmlString;

     System.Xml.Serialization.XmlSerializer xs = new System.Xml.Serialization.XmlSerializer(output.GetType());
     using (System.IO.StringWriter sw = new System.IO.StringWriter())
     {
        try
        {
           xs.Serialize(sw, output);
           objectAsXmlString = sw.ToString();
        }
        catch (Exception ex)
        {
           objectAsXmlString = ex.ToString();
        }
     }

     return objectAsXmlString;
  }

You'll see that the method might also return the exception rather than the serialized object, so you'll want to ensure that the objects you want to log are serializable.

Correct way to synchronize ArrayList in java

You're synchronizing twice, which is pointless and possibly slows down the code: changes while iterating over the list need a synchronnization over the entire operation, which you are doing with synchronized (in_queue_list) Using Collections.synchronizedList() is superfluous in that case (it creates a wrapper that synchronizes individual operations).

However, since you are emptying the list completely, the iterated removal of the first element is the worst possible way to do it, sice for each element all following elements have to be copied, making this an O(n^2) operation - horribly slow for larger lists.

Instead, simply call clear() - no iteration needed.

Edit: If you need the single-method synchronization of Collections.synchronizedList() later on, then this is the correct way:

List<Record> in_queue_list = Collections.synchronizedList(in_queue);
in_queue_list.clear(); // synchronized implicitly, 

But in many cases, the single-method synchronization is insufficient (e.g. for all iteration, or when you get a value, do computations based on it, and replace it with the result). In that case, you have to use manual synchronization anyway, so Collections.synchronizedList() is just useless additional overhead.

Curl error: Operation timed out

Some time this error in Joomla appear because some thing incorrect with SESSION or coockie. That may because incorrect HTTPd server setting or because some before CURL or Server http requests

so PHP code like:

  curl_setopt($ch, CURLOPT_URL, $url_page);
  curl_setopt($ch, CURLOPT_HEADER, 1);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
  curl_setopt($ch, CURLOPT_TIMEOUT, 30); 
  curl_setopt($ch, CURLOPT_COOKIESESSION, TRUE);
  curl_setopt($ch, CURLOPT_REFERER, $url_page);
  curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
  curl_setopt($ch, CURLOPT_COOKIEFILE, dirname(__FILE__) . "./cookie.txt");
  curl_setopt($ch, CURLOPT_COOKIEJAR, dirname(__FILE__) . "./cookie.txt");
  curl_setopt($ch, CURLOPT_COOKIE, session_name() . '=' . session_id());

  curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
  if( $sc != "" ) curl_setopt($ch, CURLOPT_COOKIE, $sc);

will need replace to PHP code

  curl_setopt($ch, CURLOPT_URL, $url_page);
  curl_setopt($ch, CURLOPT_HEADER, 1);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
  curl_setopt($ch, CURLOPT_TIMEOUT, 30); 
//curl_setopt($ch, CURLOPT_COOKIESESSION, TRUE);
  curl_setopt($ch, CURLOPT_REFERER, $url_page);
  curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
//curl_setopt($ch, CURLOPT_COOKIEFILE, dirname(__FILE__) . "./cookie.txt");
//curl_setopt($ch, CURLOPT_COOKIEJAR, dirname(__FILE__) . "./cookie.txt");
//curl_setopt($ch, CURLOPT_COOKIE, session_name() . '=' . session_id());

    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false); // !!!!!!!!!!!!!
  //if( $sc != "" ) curl_setopt($ch, CURLOPT_COOKIE, $sc);

May be some body reply how this options connected with "Curl error: Operation timed out after .."

What is the best way to compare floats for almost-equality in Python?

For some of the cases where you can affect the source number representation, you can represent them as fractions instead of floats, using integer numerator and denominator. That way you can have exact comparisons.

See Fraction from fractions module for details.

Angularjs dynamic ng-pattern validation

I just ran into this the other day.

What I did, which seems easier than the above, is to set the pattern on a variable on the scope and refer to it in ng-pattern in the view.

When "the checkbox is unchecked" I simply set the regex value to /.*/ on the onChanged callback (if going to unchecked). ng-pattern picks that change up and says "OK, your value is fine". Form is now valid. I would also remove the bad data from the field so you don't have an apparent bad phone # sitting there.

I had additional issues around ng-required, and did the same thing. Worked like a charm.

How to check if ZooKeeper is running or up from command prompt?

echo stat | nc localhost 2181 | grep Mode
echo srvr | nc localhost 2181 | grep Mode #(From 3.3.0 onwards)

Above will work in whichever modes Zookeeper is running (standalone or embedded).

Another way

If zookeeper is running in standalone mode, its a JVM process. so -

jps | grep Quorum

will display list of jvm processes; something like this for zookeeper with process ID

HQuorumPeer

How to create a MySQL hierarchical recursive query?

From the blog Managing Hierarchical Data in MySQL

Table structure

+-------------+----------------------+--------+
| category_id | name                 | parent |
+-------------+----------------------+--------+
|           1 | ELECTRONICS          |   NULL |
|           2 | TELEVISIONS          |      1 |
|           3 | TUBE                 |      2 |
|           4 | LCD                  |      2 |
|           5 | PLASMA               |      2 |
|           6 | PORTABLE ELECTRONICS |      1 |
|           7 | MP3 PLAYERS          |      6 |
|           8 | FLASH                |      7 |
|           9 | CD PLAYERS           |      6 |
|          10 | 2 WAY RADIOS         |      6 |
+-------------+----------------------+--------+

Query:

SELECT t1.name AS lev1, t2.name as lev2, t3.name as lev3, t4.name as lev4
FROM category AS t1
LEFT JOIN category AS t2 ON t2.parent = t1.category_id
LEFT JOIN category AS t3 ON t3.parent = t2.category_id
LEFT JOIN category AS t4 ON t4.parent = t3.category_id
WHERE t1.name = 'ELECTRONICS';

Output

+-------------+----------------------+--------------+-------+
| lev1        | lev2                 | lev3         | lev4  |
+-------------+----------------------+--------------+-------+
| ELECTRONICS | TELEVISIONS          | TUBE         | NULL  |
| ELECTRONICS | TELEVISIONS          | LCD          | NULL  |
| ELECTRONICS | TELEVISIONS          | PLASMA       | NULL  |
| ELECTRONICS | PORTABLE ELECTRONICS | MP3 PLAYERS  | FLASH |
| ELECTRONICS | PORTABLE ELECTRONICS | CD PLAYERS   | NULL  |
| ELECTRONICS | PORTABLE ELECTRONICS | 2 WAY RADIOS | NULL  |
+-------------+----------------------+--------------+-------+

Most users at one time or another have dealt with hierarchical data in a SQL database and no doubt learned that the management of hierarchical data is not what a relational database is intended for. The tables of a relational database are not hierarchical (like XML), but are simply a flat list. Hierarchical data has a parent-child relationship that is not naturally represented in a relational database table. Read more

Refer the blog for more details.

EDIT:

select @pv:=category_id as category_id, name, parent from category
join
(select @pv:=19)tmp
where parent=@pv

Output:

category_id name    parent
19  category1   0
20  category2   19
21  category3   20
22  category4   21

Reference: How to do the Recursive SELECT query in Mysql?

Converting from Integer, to BigInteger

The method you want is BigInteger#valueOf(long val).

E.g.,

BigInteger bi = BigInteger.valueOf(myInteger.intValue());

Making a String first is unnecessary and undesired.

SQLSTATE[28000] [1045] Access denied for user 'root'@'localhost' (using password: YES) Symfony2

I dont know what is the exact reason but I solved the problem running:

   app/console cache:clear --env=prod

Netbeans how to set command line arguments in Java

import java.io.*;
class Main
{
public static void main(String args[]) throws IOException
{
    int n1,n2,n3,l;
    n1=Integer.parseInt(args[0]);
    n2=Integer.parseInt(args[1]);
    n3=Integer.parseInt(args[2]);
    
    if(n1>n2)
    {
        l=n1;
    }
    else
    {
        l=n2;
    }
    
    if(l<n3)
    {
        System.out.println("largest no is "+n3);
    }
    else
    {
        System.out.println("largest no is "+l);
    }
    
}}

Consider above program, in this program I want to pass 3 no's from Command Line, to do so.

Step 1 : Right Click on Cup and Saucer icon, u'll see this window

1

Step 2: Click on Properties

Step 3: Click Run _> Arguments _> type three no's eg. 32 98 16 then click OK. Plz add space between two arguments. See here

2

Step 4: Run the Program by using F6.

Switch case on type c#

Update C# 7

Yes: Source

switch(shape)
{
    case Circle c:
        WriteLine($"circle with radius {c.Radius}");
        break;
    case Rectangle s when (s.Length == s.Height):
        WriteLine($"{s.Length} x {s.Height} square");
        break;
    case Rectangle r:
        WriteLine($"{r.Length} x {r.Height} rectangle");
        break;
    default:
        WriteLine("<unknown shape>");
        break;
    case null:
        throw new ArgumentNullException(nameof(shape));
}

Prior to C# 7

No.

http://blogs.msdn.com/b/peterhal/archive/2005/07/05/435760.aspx

We get a lot of requests for addditions to the C# language and today I'm going to talk about one of the more common ones - switch on type. Switch on type looks like a pretty useful and straightforward feature: Add a switch-like construct which switches on the type of the expression, rather than the value. This might look something like this:

switch typeof(e) { 
        case int:    ... break; 
        case string: ... break; 
        case double: ... break; 
        default:     ... break; 
}

This kind of statement would be extremely useful for adding virtual method like dispatch over a disjoint type hierarchy, or over a type hierarchy containing types that you don't own. Seeing an example like this, you could easily conclude that the feature would be straightforward and useful. It might even get you thinking "Why don't those #*&%$ lazy C# language designers just make my life easier and add this simple, timesaving language feature?"

Unfortunately, like many 'simple' language features, type switch is not as simple as it first appears. The troubles start when you look at a more significant, and no less important, example like this:

class C {}
interface I {}
class D : C, I {}

switch typeof(e) {
case C: … break;
case I: … break;
default: … break;
}

Link: https://blogs.msdn.microsoft.com/peterhal/2005/07/05/many-questions-switch-on-type/

Pretty-Print JSON in Java

My situation is my project uses a legacy (non-JSR) JSON parser that does not support pretty printing. However, I needed to produce pretty-printed JSON samples; this is possible without having to add any extra libraries as long as you are using Java 7 and above:

ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine scriptEngine = manager.getEngineByName("JavaScript");
scriptEngine.put("jsonString", jsonStringNoWhitespace);
scriptEngine.eval("result = JSON.stringify(JSON.parse(jsonString), null, 2)");
String prettyPrintedJson = (String) scriptEngine.get("result");

How to place a JButton at a desired location in a JFrame using Java

Following line should be called before you add your component

pnlButton.setLayout(null);

Above will set your content panel to use absolute layout. This means you'd always have to set your component's bounds explicitly by using setBounds method.

In general I wouldn't recommend using absolute layout.

How to open select file dialog via js?

For the sake of completeness, Ron van der Heijden's solution in pure JavaScript:

<button onclick="document.querySelector('.inputFile').click();">Select File ...</button>
<input class="inputFile" type="file" style="display: none;">

Is it possible to use the SELECT INTO clause with UNION [ALL]?

I would do it like this:

SELECT top(100)* into #tmpFerdeen
FROM Customers

Insert into #tmpFerdeen
SELECT top(100)* 
FROM CustomerEurope

Insert into #tmpFerdeen
SELECT top(100)* 
FROM CustomerAsia

Insert into #tmpFerdeen
SELECT top(100)* 
FROM CustomerAmericas

How to get table list in database, using MS SQL 2008?

This should give you a list of all the tables in your database

SELECT Distinct TABLE_NAME FROM information_schema.TABLES

So you can use it similar to your database check.

If NOT EXISTS(SELECT Distinct TABLE_NAME FROM information_schema.TABLES Where TABLE_NAME = 'Your_Table')
BEGIN
    --CREATE TABLE Your_Table
END
GO

How to remove a key from Hash and get the remaining hash in Ruby/Rails?

Oneliner plain ruby, it works only with ruby > 1.9.x:

1.9.3p0 :002 > h = {:a => 1, :b => 2}
 => {:a=>1, :b=>2} 
1.9.3p0 :003 > h.tap { |hs| hs.delete(:a) }
 => {:b=>2} 

Tap method always return the object on which is invoked...

Otherwise if you have required active_support/core_ext/hash (which is automatically required in every Rails application) you can use one of the following methods depending on your needs:

?  ~  irb
1.9.3p125 :001 > require 'active_support/core_ext/hash' => true 
1.9.3p125 :002 > h = {:a => 1, :b => 2, :c => 3}
 => {:a=>1, :b=>2, :c=>3} 
1.9.3p125 :003 > h.except(:a)
 => {:b=>2, :c=>3} 
1.9.3p125 :004 > h.slice(:a)
 => {:a=>1} 

except uses a blacklist approach, so it removes all the keys listed as args, while slice uses a whitelist approach, so it removes all keys that aren't listed as arguments. There also exist the bang version of those method (except! and slice!) which modify the given hash but their return value is different both of them return an hash. It represents the removed keys for slice! and the keys that are kept for the except!:

1.9.3p125 :011 > {:a => 1, :b => 2, :c => 3}.except!(:a)
 => {:b=>2, :c=>3} 
1.9.3p125 :012 > {:a => 1, :b => 2, :c => 3}.slice!(:a)
 => {:b=>2, :c=>3} 

CSS text-align: center; is not centering things

I don't Know you use any Bootstrap version but the useful helper class for centering and block an element in center it is .center-block because this class contain margin and display CSS properties but the .text-center class only contain the text-align property

Bootstrap Helper Class center-block

Win32Exception (0x80004005): The wait operation timed out

My Table didn't have primary key then I had time out error. after set key sloved.

Comparing strings in Java

Using the == operator will compare the references to the strings not the string themselves.

Ok, you have to toString() the Editable. I loaded up some of the code I had before that dealt with this situation.

String passwd1Text = passw1.getText().toString();
String passwd2Text = passw2.getText().toString();

if (passwd1Text.equals(passwd2Text))
{
}

How do I set Tomcat Manager Application User Name and Password for NetBeans?

Netbeans Problem: For apache Tomcat server Authentication required dialog box requesting user name and password

This dialog box appear If a user role and his credentials are not set or is incorrect for Tomcat startup via NetBeans IDE,

OR when user/pass set in IDE is not matches with user/pass in "canf/tomcat-user.xml" file

1..Need to check user name and password set in IDE tools-->server

2..Check \CATALINA_BASE\conf\tomcat-users.xml. whether user and his role is defined or not. If not add these lines

<user username="ide" password="EiWnNlBG" roles="manager-script,admin"/>
</tomcat-users>

3.. set the same user/pass in IDE tools->server

  1. restart your server to get effect of changes

Source: http://ohmjavaclasses.blogspot.com/2011/12/netbeans-problem-for-apache-tomcat.html

Binding value to style

Try [attr.style]="changeBackground()"

Renaming branches remotely in Git

TL;DR

"Renaming" a remote branch is actually a 2 step process (not necessarily ordered):

  • deletion of the old remote branch (git push [space]:<old_name> as ksrb explained);
  • push into a new remote branch (difference between a couple of answers commands below).

Deleting

I use TortoiseGit and when I first tried to delete the branch through the command line, I got this:

$ git push origin :in
  • fatal: 'origin' does not appear to be a git repository

  • fatal: Could not read from remote repository.

Please make sure you have the correct access rights and the repository exists.

This was likely due to pageant not having the private key loaded (which TortoiseGit loads automatically into pageant). Moreover, I noticed that TortoiseGit commands do not have the origin ref in them (e.g. git.exe push --progress "my_project" interesting_local:interesting).

I am also using Bitbucket and, as others web-based online git managers of the sort (GitHub, GitLab), I was able to delete the remote branch directly through their interface (branches page):

Delete branch Bitbucket

However, in TortoiseGit you may also delete remote branches through Browse References:

Browse References menu

By right-clicking on a remote branch (remotes list) the Delete remote branch option shows up:

TortoiseGit remote branch delete

Pushing

After deleting the old remote branch I pushed directly into a new remote branch through TortoiseGit just by typing the new name in the Remote: field of the Push window and this branch was automatically created and visible in Bitbucket.

However, if you still prefer to do it manually, a point that has not been mentioned yet in this thread is that -u = --set-upstream.

From git push docs, -u is just an alias of --set-upstream, so the commands in the answers of Sylvain (-set-upstream new-branch) and Shashank (-u origin new_branch) are equivalent, since the remote ref defaults to origin if no other ref was previously defined:

  • git push origin -u new_branch = git push -u new_branch from the docs description:

    If the configuration is missing, it defaults to origin.

In the end, I did not manually type in or used any of the commands suggested by the other answers in here, so perhaps this might be useful to others in a similar situation.

MySQL Server has gone away when importing large sql file

If it takes a long time to fail, then enlarge the wait_timeout variable.

If it fails right away, enlarge the max_allowed_packet variable; it it still doesn't work, make sure the command is valid SQL. Mine had unescaped quotes which screwed everything up.

Also, if feasible, consider limiting the number of inserts of a single SQL command to, say, 1000. You can create a script that creates multiple statements out of a single one by reintroducing the INSERT... part every n inserts.

Setting default value in select drop-down using Angularjs

$scope.item = {
    "id": "3",
    "name": "ALL",
};

$scope.CategoryLst = [
    { id: '1', name: 'MD' },
    { id: '2', name: 'CRNA' },
    { id: '3', name: 'ALL' }];

<select ng-model="item.id" ng-selected="3" ng-options="i.id as i.name for i in CategoryLst"></select>

Is it possible to specify the schema when connecting to postgres with JDBC?

DataSourcesetCurrentSchema

When instantiating a DataSource implementation, look for a method to set the current/default schema.

For example, on the PGSimpleDataSource class call setCurrentSchema.

org.postgresql.ds.PGSimpleDataSource dataSource = new org.postgresql.ds.PGSimpleDataSource ( );
dataSource.setServerName ( "localhost" );
dataSource.setDatabaseName ( "your_db_here_" );
dataSource.setPortNumber ( 5432 );
dataSource.setUser ( "postgres" );
dataSource.setPassword ( "your_password_here" );
dataSource.setCurrentSchema ( "your_schema_name_here_" );  // <----------

If you leave the schema unspecified, Postgres defaults to a schema named public within the database. See the manual, section 5.9.2 The Public Schema. To quote hat manual:

In the previous sections we created tables without specifying any schema names. By default such tables (and other objects) are automatically put into a schema named “public”. Every new database contains such a schema.

Get key from a HashMap using the value

You mixed the keys and the values.

Hashmap <Integer,String> hashmap = new HashMap<Integer, String>();

hashmap.put(100, "one");
hashmap.put(200, "two");

Afterwards a

hashmap.get(100);

will give you "one"

Apply CSS style attribute dynamically in Angular JS

On a generic note, you can use a combination of ng-if and ng-style incorporate conditional changes with change in background image.

<span ng-if="selectedItem==item.id"
      ng-style="{'background-image':'url(../images/'+'{{item.id}}'+'_active.png)',
                'background-size':'52px 57px',
                'padding-top':'70px',
                'background-repeat':'no-repeat',
                'background-position': 'center'}">
 </span>
 <span ng-if="selectedItem!=item.id"
       ng-style="{'background-image':'url(../images/'+'{{item.id}}'+'_deactivated.png)',
                'background-size':'52px 57px',
                'padding-top':'70px',
                'background-repeat':'no-repeat',
                'background-position': 'center'}">
 </span>

Argument Exception "Item with Same Key has already been added"

That Exception is thrown if there is already a key in the dictionary when you try to add the new one.

There must be more than one line in rct3Lines with the same first word. You can't have 2 entries in the same dictionary with the same key.

You need to decide what you want to happen if the key already exists - if you want to just update the value where the key exists you can simply

rct3Features[items[0]]=items[1]

but, if not you may want to test if the key already exists with:

if(rect3Features.ContainsKey(items[0]))
{
    //Do something
} 
else 
{
    //Do something else
}

Is it possible to access to google translate api for free?

Yes, you can use GT for free. See the post with explanation. And look at repo on GitHub.

UPD 19.03.2019 Here is a version for browser on GitHub.

Pass array to mvc Action via AJAX

I work with asp.net core 2.2 and jquery and have to submit a complex object ('main class') from a view to a controller with simple data fields and some array's.
As soon as I have added the array in the c# 'main class' definition (see below) and submitted the (correct filled) array over ajax (post), the whole object was null in the controller.
First, I thought, the missing "traditional: true," to my ajax call was the reason, but this is not the case.
In my case the reason was the definition in the c# 'main class'.
In the 'main class', I had:

public List<EreignisTagNeu> oEreignistageNeu { get; set; }

and EreignisTagNeu was defined as:

public class EreignisTagNeu
{
 public int iHME_Key { get; set; } 
}

I had to change the definition in the 'main class' to:

 public List<int> oEreignistageNeu { get; set; }

Now it works.
So... for me it seems as asp.net core has a problem (with post), if the list for an array is not defined completely in the 'main class'.
Note: In my case this works with or without "traditional: true," to the ajax call

How to copy files from host to Docker container?

  1. Get container name or short container id:

    $ docker ps
    
  2. Get full container id:

    $ docker inspect -f   '{{.Id}}'  SHORT_CONTAINER_ID-or-CONTAINER_NAME
    
  3. Copy file:

    $ sudo cp path-file-host /var/lib/docker/aufs/mnt/FULL_CONTAINER_ID/PATH-NEW-FILE
    

EXAMPLE:

$ docker ps

CONTAINER ID      IMAGE    COMMAND       CREATED      STATUS       PORTS        NAMES

d8e703d7e303   solidleon/ssh:latest      /usr/sbin/sshd -D                      cranky_pare

$ docker inspect -f   '{{.Id}}' cranky_pare

or

$ docker inspect -f   '{{.Id}}' d8e703d7e303

d8e703d7e3039a6df6d01bd7fb58d1882e592a85059eb16c4b83cf91847f88e5

$ sudo cp file.txt /var/lib/docker/aufs/mnt/**d8e703d7e3039a6df6d01bd7fb58d1882e592a85059eb16c4b83cf91847f88e5**/root/file.txt

macOS on VMware doesn't recognize iOS device

I met the same problem. I found the solution in the solution from kb.vmware.com.
It works for me by adding

usb.quirks.device0 = "0xvid:0xpid skip-refresh"

Detail as below:


To add quirks:
  1. Shut down the virtual machine and quit Workstation/Fusion.

    Caution: Do not skip this step.
     
  2. Open the vmware.log file within the virtual machine bundle. For more information, see Locating a virtual machine bundle in VMware Workstation/Fusion (1007599).
  3. In the Filter box at the top of the Console window, enter the name of the device manufacturer.

    For example, if you enter the name Apple, you see a line that looks similar to:

    vmx | USB: Found device [name:Apple\ IR\ Receiver vid:05ac pid:8240 path:13/7/2 speed:full family:hid]



    The line has the name of the USB device and its vid and pid information. Make a note of the vid and pid values.
     

  4. Open the .vmx file using a text editor. For more information, see Editing the .vmx file for your Workstation/Fusion virtual machine (1014782).
  5. Add this line to the .vmx file, replacing vid and pid with the values noted in Step 2, each prefixed by the number 0 and the letter x .

    usb.quirks.device0 = "0xvid:0xpid skip-reset"

    For example, for the Apple device found in step 2, this line is:

    usb.quirks.device0 = "0x05ac:0x8240 skip-reset"
     

  6. Save the .vmx file.
  7. Re-open Workstation/Fusion. The edited .vmx file is reloaded with the changes.
  8. Start the virtual machine, and connect the device.
  9. If the issue is not resolved, replace the quirks line added in Step 4 with one of these lines, in the order provided, and repeat Steps 5 to 8:
usb.quirks.device0 = "0xvid:0xpid skip-refresh"
usb.quirks.device0 = "0xvid:0xpid skip-setconfig"
usb.quirks.device0 = "0xvid:0xpid skip-reset, skip-refresh, skip-setconfig"

Notes:

  • Use one of these lines at a time. If one does not work, replace it with another one in the list. Do not add more than one of these in the .vmx file at a time.
  • The last line uses all three quirks in combination. Use this only if the other three lines do not work.

Refer this to see in detail.

How to set a timeout on a http.request() in Node?

Curious, what happens if you use straight net.sockets instead? Here's some sample code I put together for testing purposes:

var net = require('net');

function HttpRequest(host, port, path, method) {
  return {
    headers: [],
    port: 80,
    path: "/",
    method: "GET",
    socket: null,
    _setDefaultHeaders: function() {

      this.headers.push(this.method + " " + this.path + " HTTP/1.1");
      this.headers.push("Host: " + this.host);
    },
    SetHeaders: function(headers) {
      for (var i = 0; i < headers.length; i++) {
        this.headers.push(headers[i]);
      }
    },
    WriteHeaders: function() {
      if(this.socket) {
        this.socket.write(this.headers.join("\r\n"));
        this.socket.write("\r\n\r\n"); // to signal headers are complete
      }
    },
    MakeRequest: function(data) {
      if(data) {
        this.socket.write(data);
      }

      this.socket.end();
    },
    SetupRequest: function() {
      this.host = host;

      if(path) {
        this.path = path;
      }
      if(port) {
        this.port = port;
      }
      if(method) {
        this.method = method;
      }

      this._setDefaultHeaders();

      this.socket = net.createConnection(this.port, this.host);
    }
  }
};

var request = HttpRequest("www.somesite.com");
request.SetupRequest();

request.socket.setTimeout(30000, function(){
  console.error("Connection timed out.");
});

request.socket.on("data", function(data) {
  console.log(data.toString('utf8'));
});

request.WriteHeaders();
request.MakeRequest();

What's the maximum value for an int in PHP?

(a little bit late, but could be useful)

Only trust PHP_INT_MAX and PHP_INT_SIZE, this value vary on your arch (32/64 bits) and your OS...

Any other "guess" or "hint" can be false.

How to make an installer for my C# application?

Generally speaking, it's recommended to use MSI-based installations on Windows. Thus, if you're ready to invest a fair bit of time, WiX is the way to go.

If you want something which is much more simpler, go with InnoSetup.

Determine if Android app is being used for the first time

Why not use the Database Helper ? This will have a nice onCreate which is only called the first time the app is started. This will help those people who want to track this after there initial app has been installed without tracking.

How can I Remove .DS_Store files from a Git repository?

Remove existing files from the repository:

find . -name .DS_Store -print0 | xargs -0 git rm -f --ignore-unmatch

Add the line

.DS_Store

to the file .gitignore, which can be found at the top level of your repository (or created if it isn't there already). You can do this easily with this command in the top directory

echo .DS_Store >> .gitignore

Then

git add .gitignore
git commit -m '.DS_Store banished!'

Set a path variable with spaces in the path in a Windows .cmd file or batch file

I always place the path in double quotes when I am creating a .bat file. (I just added the PAUSE so it wont close the screen.)

For example:

"C:\Program Files\PageTech\PCLReader64_131\PCLReader64.exe"
PAUSE

Random character generator with a range of (A..Z, 0..9) and punctuation

You should first make a String that holds all of the letters/numbers that you want.
Then, make a Random. e. g. Random rnd = new Random;
Finally, make something that actually gets a random character from your String containing your alphabet.
For example,

import java.util.Random;

public class randomCharacter {
    public static void main(String[] args) {
        String alphabet = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ?/.,";
        Random rnd = new Random();
        char char = alphabet.charAt(rnd.nextInt(alphabet.length()));
        // do whatever you want with the character
    }
}

See this.
It's where I got this info from.

How do I unload (reload) a Python module?

reload(module), but only if it's completely stand-alone. If anything else has a reference to the module (or any object belonging to the module), then you'll get subtle and curious errors caused by the old code hanging around longer than you expected, and things like isinstance not working across different versions of the same code.

If you have one-way dependencies, you must also reload all modules that depend on the reloaded module to get rid of all the references to the old code. And then reload modules that depend on the reloaded modules, recursively.

If you have circular dependencies, which is very common for example when you are dealing with reloading a package, you must unload all the modules in the group in one go. You can't do this with reload() because it will re-import each module before its dependencies have been refreshed, allowing old references to creep into new modules.

The only way to do it in this case is to hack sys.modules, which is kind of unsupported. You'd have to go through and delete each sys.modules entry you wanted to be reloaded on next import, and also delete entries whose values are None to deal with an implementation issue to do with caching failed relative imports. It's not terribly nice but as long as you have a fully self-contained set of dependencies that doesn't leave references outside its codebase, it's workable.

It's probably best to restart the server. :-)

Android: How to open a specific folder via Intent and show its content in a file browser?

This should work:

Uri selectedUri = Uri.parse(Environment.getExternalStorageDirectory() + "/myFolder/");
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(selectedUri, "resource/folder");

if (intent.resolveActivityInfo(getPackageManager(), 0) != null)
{
    startActivity(intent);
}
else
{
    // if you reach this place, it means there is no any file 
    // explorer app installed on your device
}

Please, be sure that you have any file explorer app installed on your device.

EDIT: added a shantanu's recommendation from the comment.

LIBRARIES: You can also have a look at the following libraries https://android-arsenal.com/tag/35 if the current solution doesn't help you.

How to know Laravel version and where is it defined?

If you want to know the user version in your code, then you can use using app() helper function

app()->version();

It is defined in this file ../src/Illuminate/Foundation/Application.php

Hope it will help :)

Passing a String by Reference in Java?

You have three options:

  1. Use a StringBuilder:

    StringBuilder zText = new StringBuilder ();
    void fillString(StringBuilder zText) { zText.append ("foo"); }
    
  2. Create a container class and pass an instance of the container to your method:

    public class Container { public String data; }
    void fillString(Container c) { c.data += "foo"; }
    
  3. Create an array:

    new String[] zText = new String[1];
    zText[0] = "";
    
    void fillString(String[] zText) { zText[0] += "foo"; }
    

From a performance point of view, the StringBuilder is usually the best option.

How can I clone a private GitLab repository?

If you're trying this with GitHub, you can do this with your SSH entered:

git clone https://[email protected]/username/repository

Change navbar text color Bootstrap

.nav-link {
color: blue !important;
}

Worked for me. Bootstrap v4.3.1

PHP check if date between two dates

Based on luttken's answer. Thought I'd add my twist :)

function dateIsInBetween(\DateTime $from, \DateTime $to, \DateTime $subject)
{
    return $subject->getTimestamp() > $from->getTimestamp() && $subject->getTimestamp() < $to->getTimestamp() ? true : false;
}

$paymentDate       = new \DateTime('now');
$contractDateBegin = new \DateTime('01/01/2001');
$contractDateEnd   = new \DateTime('01/01/2016');

echo dateIsInBetween($contractDateBegin, $contractDateEnd, $paymentDate) ? "is between" : "NO GO!";

How to count items in JSON object using command line?

A simple solution is to install jshon library :

jshon -l < /tmp/test.json
2

How can I tell what edition of SQL Server runs on the machine?

You can get just the edition name by using the following steps.

  • Open "SQL Server Configuration Manager"
  • From the List of SQL Server Services, Right Click on "SQL Server (Instance_name)" and Select Properties.
  • Select "Advanced" Tab from the Properties window.
  • Verify Edition Name from the "Stock Keeping Unit Name"
  • Verify Edition Id from the "Stock Keeping Unit Id"
  • Verify Service Pack from the "Service Pack Level"
  • Verify Version from the "Version"

screen shot

Is Java a Compiled or an Interpreted programming language ?

Java implementations typically use a two-step compilation process. Java source code is compiled down to bytecode by the Java compiler. The bytecode is executed by a Java Virtual Machine (JVM). Modern JVMs use a technique called Just-in-Time (JIT) compilation to compile the bytecode to native instructions understood by hardware CPU on the fly at runtime.

Some implementations of JVM may choose to interpret the bytecode instead of JIT compiling it to machine code, and running it directly. While this is still considered an "interpreter," It's quite different from interpreters that read and execute the high level source code (i.e. in this case, Java source code is not interpreted directly, the bytecode, output of Java compiler, is.)

It is technically possible to compile Java down to native code ahead-of-time and run the resulting binary. It is also possible to interpret the Java code directly.

To summarize, depending on the execution environment, bytecode can be:

  • compiled ahead of time and executed as native code (similar to most C++ compilers)
  • compiled just-in-time and executed
  • interpreted
  • directly executed by a supported processor (bytecode is the native instruction set of some CPUs)

How to use log levels in java

Generally, you don't need all those levels, SEVERE, WARNING, INFO, FINE might be enough. We're using Log4J (not java.util.logging directly) and the following levels (which might differ in name from other logging frameworks):

  • ERROR: Any error/exception that is or might be critical. Our Logger automatically sends an email for each such message on our servers (usage: logger.error("message"); )

  • WARN: Any message that might warn us of potential problems, e.g. when a user tried to log in with wrong credentials - which might indicate an attack if that happens often or in short periods of time (usage: logger.warn("message"); )

  • INFO: Anything that we want to know when looking at the log files, e.g. when a scheduled job started/ended (usage: logger.info("message"); )

  • DEBUG: As the name says, debug messages that we only rarely turn on. (usage: logger.debug("message"); )

The beauty of this is that if you set the log level to WARN, info and debug messages have next to no performance impact. If you need to get additional information from a production system you just can lower the level to INFO or DEBUG for a short period of time (since you'd get much more log entries which make your log files bigger and harder to read). Adjusting log levels etc. can normally be done at runtime (our JBoss instance checks for changes in that config every minute or so).

Docker - a way to give access to a host USB or serial device?

It's hard for us to bind a specific USB device to a docker container which is also specific. As you can see, the recommended way to achieve is:

docker run -t -i --privileged -v /dev/bus/usb:/dev/bus/usb ubuntu bash

It will bind all the devices to this container. It's unsafe. Every containers were granted to operate all of them.

Another way is binding devices by devpath. It may looks like:

docker run -t -i --privileged -v /dev/bus/usb/001/002:/dev/bus/usb/001/002 ubuntu bash

or --device (better, no privileged):

docker run -t -i --device /dev/bus/usb/001/002 ubuntu bash

Much safer. But actually it is hard to know what the devpath of a specific device is.

I have wrote this repo to solve this problem.

https://github.com/williamfzc/usb2container

After deploying this server, you can easily get all the connected devices' information via HTTP request:

curl 127.0.0.1:9410/api/device

and get:

{
    "/devices/pci0000:00/0000:00:14.0/usb1/1-13": {
        "ACTION": "add",
        "DEVPATH": "/devices/pci0000:00/0000:00:14.0/usb1/1-13",
        "DEVTYPE": "usb_device",
        "DRIVER": "usb",
        "ID_BUS": "usb",
        "ID_FOR_SEAT": "xxxxx",
        "ID_MODEL": "xxxxx",
        "ID_MODEL_ID": "xxxxx",
        "ID_PATH": "xxxxx",
        "ID_PATH_TAG": "xxxxx",
        "ID_REVISION": "xxxxx",
        "ID_SERIAL": "xxxxx",
        "ID_SERIAL_SHORT": "xxxxx",
        "ID_USB_INTERFACES": "xxxxx",
        "ID_VENDOR": "xxxxx",
        "ID_VENDOR_ENC": "xxxxx",
        "ID_VENDOR_FROM_DATABASE": "",
        "ID_VENDOR_ID": "xxxxx",
        "INTERFACE": "",
        "MAJOR": "189",
        "MINOR": "119",
        "MODALIAS": "",
        "PRODUCT": "xxxxx",
        "SEQNUM": "xxxxx",
        "SUBSYSTEM": "usb",
        "TAGS": "",
        "TYPE": "0/0/0",
        "USEC_INITIALIZED": "xxxxx",
        "adb_user": "",
        "_empty": false,
        "DEVNAME": "/dev/bus/usb/001/120",
        "BUSNUM": "001",
        "DEVNUM": "120",
        "ID_MODEL_ENC": "xxxxx"
    },
    ...
}

and bind them to your containers. For example, you can see the DEVNAME of this device is /dev/bus/usb/001/120:

docker run -t -i --device /dev/bus/usb/001/120 ubuntu bash

Maybe it will help.

React.js: onChange event for contentEditable

This probably isn't exactly the answer you're looking for, but having struggled with this myself and having issues with suggested answers, I decided to make it uncontrolled instead.

When editable prop is false, I use text prop as is, but when it is true, I switch to editing mode in which text has no effect (but at least browser doesn't freak out). During this time onChange are fired by the control. Finally, when I change editable back to false, it fills HTML with whatever was passed in text:

/** @jsx React.DOM */
'use strict';

var React = require('react'),
    escapeTextForBrowser = require('react/lib/escapeTextForBrowser'),
    { PropTypes } = React;

var UncontrolledContentEditable = React.createClass({
  propTypes: {
    component: PropTypes.func,
    onChange: PropTypes.func.isRequired,
    text: PropTypes.string,
    placeholder: PropTypes.string,
    editable: PropTypes.bool
  },

  getDefaultProps() {
    return {
      component: React.DOM.div,
      editable: false
    };
  },

  getInitialState() {
    return {
      initialText: this.props.text
    };
  },

  componentWillReceiveProps(nextProps) {
    if (nextProps.editable && !this.props.editable) {
      this.setState({
        initialText: nextProps.text
      });
    }
  },

  componentWillUpdate(nextProps) {
    if (!nextProps.editable && this.props.editable) {
      this.getDOMNode().innerHTML = escapeTextForBrowser(this.state.initialText);
    }
  },

  render() {
    var html = escapeTextForBrowser(this.props.editable ?
      this.state.initialText :
      this.props.text
    );

    return (
      <this.props.component onInput={this.handleChange}
                            onBlur={this.handleChange}
                            contentEditable={this.props.editable}
                            dangerouslySetInnerHTML={{__html: html}} />
    );
  },

  handleChange(e) {
    if (!e.target.textContent.trim().length) {
      e.target.innerHTML = '';
    }

    this.props.onChange(e);
  }
});

module.exports = UncontrolledContentEditable;

Can an angular directive pass arguments to functions in expressions specified in the directive's attributes?

If you declare your callback as mentioned by @lex82 like

callback = "callback(item.id, arg2)"

You can call the callback method in the directive scope with object map and it would do the binding correctly. Like

scope.callback({arg2:"some value"});

without requiring for $parse. See my fiddle(console log) http://jsfiddle.net/k7czc/2/

Update: There is a small example of this in the documentation:

& or &attr - provides a way to execute an expression in the context of the parent scope. If no attr name is specified then the attribute name is assumed to be the same as the local name. Given and widget definition of scope: { localFn:'&myAttr' }, then isolate scope property localFn will point to a function wrapper for the count = count + value expression. Often it's desirable to pass data from the isolated scope via an expression and to the parent scope, this can be done by passing a map of local variable names and values into the expression wrapper fn. For example, if the expression is increment(amount) then we can specify the amount value by calling the localFn as localFn({amount: 22}).

Full path from file input using jQuery

You can't: It's a security feature in all modern browsers.

For IE8, it's off by default, but can be reactivated using a security setting:

When a file is selected by using the input type=file object, the value of the value property depends on the value of the "Include local directory path when uploading files to a server" security setting for the security zone used to display the Web page containing the input object.

The fully qualified filename of the selected file is returned only when this setting is enabled. When the setting is disabled, Internet Explorer 8 replaces the local drive and directory path with the string C:\fakepath\ in order to prevent inappropriate information disclosure.

In all other current mainstream browsers I know of, it is also turned off. The file name is the best you can get.

More detailed info and good links in this question. It refers to getting the value server-side, but the issue is the same in JavaScript before the form's submission.

Is the Scala 2.8 collections library a case of "the longest suicide note in history"?

One way that the Scala community can help ease the fear of programmers new to Scala is to focus on practice and to teach by example--a lot of examples that start small and grow gradually larger. Here are a few sites that take this approach:

After spending some time on these sites, one quickly realizes that Scala and its libraries, though perhaps difficult to design and implement, are not so difficult to use, especially in the common cases.

Using partial views in ASP.net MVC 4

You're passing the same model to the partial view as is being passed to the main view, and they are different types. The model is a DbSet of Notes, where you need to pass in a single Note.

You can do this by adding a parameter, which I'm guessing as it's the create form would be a new Note

@Html.Partial("_CreateNote", new QuickNotes.Models.Note())

Bootstrap change carousel height

From Bootstrap 4

.carousel-item{
    height: 200px;
} 
.carousel-item img{
    height: 200px;
}

How can I generate an apk that can run without server with react-native?

You should just use android studio for this process. It is just simpler. But first run this command in your react native app directory:

For Newer version of react-native(e.g. react native 0.49.0 & so on...)

react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res

For Older Version of react-native (0.49.0 & below)

react-native bundle --platform android --dev false --entry-file index.android.js   --bundle-output android/app/src/main/assets/index.android.bundle   --assets-dest android/app/src/main/res/

Then Use android studio to open the 'android' folder in you react native app directory, it will ask to upgrade gradle and some other stuff. go to build-> Generate signed APK and follow the instructions from there. It's really straight forward.

ClassNotFoundException com.mysql.jdbc.Driver

In NetBeans,

  1. right click on libraries, select properties
  2. select rub tab
  3. there you need to add the mysql-connector-java.jar and apply

Warning about SSL connection when connecting to MySQL database

I use this property for hibernate in config xml

<property name="hibernate.connection.url">
jdbc:mysql://localhost:3306/bookshop?serverTimezone=UTC&amp;useSSL=false
</property>

without - serverTimezone=UTC - it doesn't work

What does an exclamation mark mean in the Swift language?

Some big picture perspective to add to the other useful but more detail-centric answers:

In Swift, the exclamation point appears in several contexts:

  • Forced unwrapping: let name = nameLabel!.text
  • Implicitly unwrapped optionals: var logo: UIImageView!
  • Forced casting: logo.image = thing as! UIImage
  • Unhandled exceptions: try! NSJSONSerialization.JSONObjectWithData(data, [])

Every one of these is a different language construct with a different meaning, but they all have three important things in common:

1. Exclamation points circumvent Swift’s compile-time safety checks.

When you use ! in Swift, you are essentially saying, “Hey, compiler, I know you think an error could happen here, but I know with total certainty that it never will.”

Not all valid code fits into the box of Swift’s compile-time type system — or any language’s static type checking, for that matter. There are situations where you can logically prove that an error will never happen, but you can’t prove it to the compiler. That’s why Swift’s designers added these features in the first place.

However, whenever you use !, you’re ruling out having a recovery path for an error, which means that…

2. Exclamation points are potential crashes.

An exclamation point also says, “Hey Swift, I am so certain that this error can never happen that it’s better for you to crash my whole app than it is for me to code a recovery path for it.”

That’s a dangerous assertion. It can be the correct one: in mission-critical code where you have thought hard about your code’s invariants, it may be that bogus output is worse than a crash.

However, when I see ! in the wild, it's rarely used so mindfully. Instead, it too often means, “this value was optional and I didn’t really think too hard about why it could be nil or how to properly handle that situation, but adding ! made it compile … so my code is correct, right?”

Beware the arrogance of the exclamation point. Instead…

3. Exclamation points are best used sparingly.

Every one of these ! constructs has a ? counterpart that forces you to deal with the error/nil case:

  • Conditional unwrapping: if let name = nameLabel?.text { ... }
  • Optionals: var logo: UIImageView?
  • Conditional casts: logo.image = thing as? UIImage
  • Nil-on-failure exceptions: try? NSJSONSerialization.JSONObjectWithData(data, [])

If you are tempted to use !, it is always good to consider carefully why you are not using ? instead. Is crashing your program really the best option if the ! operation fails? Why is that value optional/failable?

Is there a reasonable recovery path your code could take in the nil/error case? If so, code it.

If it can’t possibly be nil, if the error can never happen, then is there a reasonable way to rework your logic so that the compiler knows that? If so, do it; your code will be less error-prone.

There are times when there is no reasonable way to handle an error, and simply ignoring the error — and thus proceeding with wrong data — would be worse than crashing. Those are the times to use force unwrapping.

I periodically search my entire codebase for ! and audit every use of it. Very few usages stand up to scrutiny. (As of this writing, the entire Siesta framework has exactly two instances of it.)

That’s not to say you should never use ! in your code — just that you should use it mindfully, and never make it the default option.

Android Writing Logs to text File

In general, you must have a file handle before opening the stream. You have a fileOutputStream handle before createNewFile() in the else block. The stream does not create the file if it doesn't exist.

Not really android specific, but that's a lot IO for this purpose. What if you do many "write" operations one after another? You will be reading the entire contents and writing the entire contents, taking time, and more importantly, battery life.

I suggest using java.io.RandomAccessFile, seek()'ing to the end, then writeChars() to append. It will be much cleaner code and likely much faster.

Real world use of JMS/message queues?

Use them all the time to process long-running operations asynchronously. A web user won't want to wait for more than 5 seconds for a request to process. If you have one that runs longer than that, one design is to submit the request to a queue and immediately send back a URL that the user can check to see when the job is finished.

Publish/subscribe is another good technique for decoupling senders from many receivers. It's a flexible architecture, because subscribers can come and go as needed.

Can you autoplay HTML5 videos on the iPad?

iOS 10 update

The ban on autoplay has been lifted as of iOS 10 - but with some restrictions (e.g. A can be autoplayed if there is no audio track).

To see a full list of these restrictions, see the official docs: https://webkit.org/blog/6784/new-video-policies-for-ios/

iOS 9 and before

As of iOS 6.1, it is no longer possible to auto-play videos on the iPad.

My assumption as to why they've disabled the auto-play feature?

Well, as many device owners have data usage/bandwidth limits on their devices, I think Apple felt that the user themselves should decide when they initiate bandwidth usage.


After a bit of research I found the following extract in the Apple documentation in regard to auto-play on iOS devices to confirm my assumption:

"Apple has made the decision to disable the automatic playing of video on iOS devices, through both script and attribute implementations.

In Safari, on iOS (for all devices, including iPad), where the user may be on a cellular network and be charged per data unit, preload and auto-play are disabled. No data is loaded until the user initiates it." - Apple documentation.

Here is a separate warning featured on the Safari HTML5 Reference page about why embedded media cannot be played in Safari on iOS:

Warning: To prevent unsolicited downloads over cellular networks at the user’s expense, embedded media cannot be played automatically in Safari on iOS—the user always initiates playback. A controller is automatically supplied on iPhone or iPod touch once playback in initiated, but for iPad you must either set the controls attribute or provide a controller using JavaScript.


What this means (in terms of code) is that Javascript's play() and load() methods are inactive until the user initiates playback, unless the play() or load() method is triggered by user action (e.g. a click event).

Basically, a user-initiated play button works, but an onLoad="play()" event does not.

For example, this would play the movie:

<input type="button" value="Play" onclick="document.myMovie.play()">

Whereas the following would do nothing on iOS:

<body onload="document.myMovie.play()">

Bootstrap select dropdown list placeholder

Bootstrap select has an noneSelectedText option. You can set it via data-none-selected-text attribute. Documentation.

Remove/ truncate leading zeros by javascript/jquery

Simply try to multiply by one as following:

"00123" * 1;              // Get as number
"00123" * 1 + "";       // Get as string

How to config Tomcat to serve images from an external folder outside webapps?

You could have a redirect servlet. In you web.xml you'd have:

<servlet>
    <servlet-name>images</servlet-name>
    <servlet-class>com.example.images.ImageServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>images</servlet-name>
    <url-pattern>/images/*</url-pattern>
</servlet-mapping>

All your images would be in "/images", which would be intercepted by the servlet. It would then read in the relevant file in whatever folder and serve it right back out. For example, say you have a gif in your images folder, c:\Server_Images\smilie.gif. In the web page would be <img src="http:/example.com/app/images/smilie.gif".... In the servlet, HttpServletRequest.getPathInfo() would yield "/smilie.gif". Which the servlet would find in the folder.

ASP.NET Core Get Json Array using IConfiguration

public class MyArray : List<string> { }

services.Configure<ShipmentDetailsDisplayGidRoles>(Configuration.GetSection("MyArray"));

public SomeController(IOptions<MyArray> myArrayOptions)
{
    myArray = myArrayOptions.Value;
}

Permission denied error on Github Push

  • click fork button on original github project page
  • clone your forked repository instead original
  • push to it
  • press Pull Requests button on your repository
  • create it
  • wait for original author to accept it

What does the term "canonical form" or "canonical representation" in Java mean?

Wikipedia points to the term Canonicalization.

A process for converting data that has more than one possible representation into a "standard" canonical representation. This can be done to compare different representations for equivalence, to count the number of distinct data structures, to improve the efficiency of various algorithms by eliminating repeated calculations, or to make it possible to impose a meaningful sorting order.

The Unicode example made the most sense to me:

Variable-length encodings in the Unicode standard, in particular UTF-8, have more than one possible encoding for most common characters. This makes string validation more complicated, since every possible encoding of each string character must be considered. A software implementation which does not consider all character encodings runs the risk of accepting strings considered invalid in the application design, which could cause bugs or allow attacks. The solution is to allow a single encoding for each character. Canonicalization is then the process of translating every string character to its single allowed encoding. An alternative is for software to determine whether a string is canonicalized, and then reject it if it is not. In this case, in a client/server context, the canonicalization would be the responsibility of the client.

In summary, a standard form of representation for data. From this form you can then convert to any representation you may need.

What is the difference between MySQL, MySQLi and PDO?

Specifically, the MySQLi extension provides the following extremely useful benefits over the old MySQL extension..

OOP Interface (in addition to procedural) Prepared Statement Support Transaction + Stored Procedure Support Nicer Syntax Speed Improvements Enhanced Debugging

PDO Extension

PHP Data Objects extension is a Database Abstraction Layer. Specifically, this is not a MySQL interface, as it provides drivers for many database engines (of course including MYSQL).

PDO aims to provide a consistent API that means when a database engine is changed, the code changes to reflect this should be minimal. When using PDO, your code will normally "just work" across many database engines, simply by changing the driver you're using.

In addition to being cross-database compatible, PDO also supports prepared statements, stored procedures and more, whilst using the MySQL Driver.

Set database from SINGLE USER mode to MULTI USER

The “user is currently connected to it” might be SQL Server Management Studio window itself. Try selecting the master database and running the ALTER query again.

Clear and reset form input fields

This one works best to reset the form.

import React, { Component } from 'react'
class MyComponent extends Component {
  constructor(props){
    super(props)
    this.state = {
      inputVal: props.inputValue
    }
    // preserve the initial state in a new object
    this.baseState = this.state ///>>>>>>>>> note this one.
  }
  resetForm = () => {
    this.setState(this.baseState) ///>>>>>>>>> note this one.
  }
  submitForm = () => {
    // submit the form logic
  }
  updateInput = val => this.setState({ inputVal: val })
  render() {
    return (
      <form>
        <input
          onChange={this.updateInput}
          type="text
          value={this.state.inputVal} />
        <button
          onClick={this.resetForm}
          type="button">Cancel</button>
        <button
          onClick={this.submitForm}
          type="submit">Submit</button>
      </form>
    )
  }
}

Set a default parameter value for a JavaScript function

def read_file(file, delete_after = false)
  # code
end

Following code may work in this situation including ECMAScript 6 (ES6) as well as earlier versions.

_x000D_
_x000D_
function read_file(file, delete_after) {_x000D_
    if(delete_after == undefined)_x000D_
        delete_after = false;//default value_x000D_
_x000D_
    console.log('delete_after =',delete_after);_x000D_
}_x000D_
read_file('text1.txt',true);_x000D_
read_file('text2.txt');
_x000D_
_x000D_
_x000D_

as default value in languages works when the function's parameter value is skipped when calling, in JavaScript it is assigned to undefined. This approach doesn't look attractive programmatically but have backward compatibility.

Can I use an image from my local file system as background in HTML?

background: url(../images/backgroundImage.jpg) no-repeat center center fixed;

this should help

.aspx vs .ashx MAIN difference

.aspx is a rendered page. If you need a view, use an .aspx page. If all you need is backend functionality but will be staying on the same view, use an .ashx page.

When do you use map vs flatMap in RxJava?

The way I think about it is that you use flatMap when the function you wanted to put inside of map() returns an Observable. In which case you might still try to use map() but it would be unpractical. Let me try to explain why.

If in such case you decided to stick with map, you would get an Observable<Observable<Something>>. For example in your case, if we used an imaginary RxGson library, that returned an Observable<String> from it's toJson() method (instead of simply returning a String) it would look like this:

Observable.from(jsonFile).map(new Func1<File, Observable<String>>() {
    @Override public Observable<String>> call(File file) {
        return new RxGson().toJson(new FileReader(file), Object.class);
    }
}); // you get Observable<Observable<String>> here

At this point it would be pretty tricky to subscribe() to such an observable. Inside of it you would get an Observable<String> to which you would again need to subscribe() to get the value. Which is not practical or nice to look at.

So to make it useful one idea is to "flatten" this observable of observables (you might start to see where the name _flat_Map comes from). RxJava provides a few ways to flatten observables and for sake of simplicity lets assume merge is what we want. Merge basically takes a bunch of observables and emits whenever any of them emits. (Lots of people would argue switch would be a better default. But if you're emitting just one value, it doesn't matter anyway.)

So amending our previous snippet we would get:

Observable.from(jsonFile).map(new Func1<File, Observable<String>>() {
    @Override public Observable<String>> call(File file) {
        return new RxGson().toJson(new FileReader(file), Object.class);
    }
}).merge(); // you get Observable<String> here

This is a lot more useful, because subscribing to that (or mapping, or filtering, or...) you just get the String value. (Also, mind you, such variant of merge() does not exist in RxJava, but if you understand the idea of merge then I hope you also understand how that would work.)

So basically because such merge() should probably only ever be useful when it succeeds a map() returning an observable and so you don't have to type this over and over again, flatMap() was created as a shorthand. It applies the mapping function just as a normal map() would, but later instead of emitting the returned values it also "flattens" (or merges) them.

That's the general use case. It is most useful in a codebase that uses Rx allover the place and you've got many methods returning observables, which you want to chain with other methods returning observables.

In your use case it happens to be useful as well, because map() can only transform one value emitted in onNext() into another value emitted in onNext(). But it cannot transform it into multiple values, no value at all or an error. And as akarnokd wrote in his answer (and mind you he's much smarter than me, probably in general, but at least when it comes to RxJava) you shouldn't throw exceptions from your map(). So instead you can use flatMap() and

return Observable.just(value);

when all goes well, but

return Observable.error(exception);

when something fails.
See his answer for a complete snippet: https://stackoverflow.com/a/30330772/1402641

php variable in html no other way than: <?php echo $var; ?>

In a php section before the HTML section, use sprinf() to create a constant string from the variables:

$mystuff = sprinf("My name is %s and my mother's name is %s","Suzy","Caroline");

Then in the HTML section you can do whatever you like, such as:

<p>$mystuff</p> 

In C#, should I use string.Empty or String.Empty or "" to intitialize a string?

The compiler should make them all the same in the long run. Pick a standard so that your code will be easy to read, and stick with it.

Python Anaconda - How to Safely Uninstall

I simply:

rm -rf ~/anaconda3

...this removed conda also.

Then:

mousepad ~/.bashrc

...and removed the path line added at the very bottom (clearly identified by Anaconda as 'added by Anaconda'.

Worth noting that anaconda3 created a backup of my .bashrc file before modification, and named it as:

./bashrc-anaconda3.bak

...so I could always have just renamed this and deleted my modified .bashrc

onclick="javascript:history.go(-1)" not working in Chrome

Why not get rid of the inline javascript and do something like this instead?

Inline javascript is considered bad practice as it is outdated.

Notes

Why use addEventListener?

addEventListener is the way to register an event listener as specified in W3C DOM. Its benefits are as follows:

It allows adding more than a single handler for an event. This is particularly useful for DHTML libraries or Mozilla extensions that need to work well even if other libraries/extensions are used. It gives you finer-grained control of the phase when the listener gets activated (capturing vs. bubbling) It works on any DOM element, not just HTML elements.

<a id="back" href="www.mypage.com"> Link </a>

document.getElementById("back").addEventListener("click", window.history.back, false);

On jsfiddle

How to implement one-to-one, one-to-many and many-to-many relationships while designing tables?

One to one (1-1) relationship: This is relationship between primary & foreign key (primary key relating to foreign key only one record). this is one to one relationship.

One to Many (1-M) relationship: This is also relationship between primary & foreign keys relationships but here primary key relating to multiple records (i.e. Table A have book info and Table B have multiple publishers of one book).

Many to Many (M-M): Many to many includes two dimensions, explained fully as below with sample.

-- This table will hold our phone calls.
CREATE TABLE dbo.PhoneCalls
(
   ID INT IDENTITY(1, 1) NOT NULL,
   CallTime DATETIME NOT NULL DEFAULT GETDATE(),
   CallerPhoneNumber CHAR(10) NOT NULL
)
-- This table will hold our "tickets" (or cases).
CREATE TABLE dbo.Tickets
(
   ID INT IDENTITY(1, 1) NOT NULL,
   CreatedTime DATETIME NOT NULL DEFAULT GETDATE(),
   Subject VARCHAR(250) NOT NULL,
   Notes VARCHAR(8000) NOT NULL,
   Completed BIT NOT NULL DEFAULT 0
)
-- This table will link a phone call with a ticket.
CREATE TABLE dbo.PhoneCalls_Tickets
(
   PhoneCallID INT NOT NULL,
   TicketID INT NOT NULL
)

Hash Table/Associative Array in VBA

I think you are looking for the Dictionary object, found in the Microsoft Scripting Runtime library. (Add a reference to your project from the Tools...References menu in the VBE.)

It pretty much works with any simple value that can fit in a variant (Keys can't be arrays, and trying to make them objects doesn't make much sense. See comment from @Nile below.):

Dim d As dictionary
Set d = New dictionary

d("x") = 42
d(42) = "forty-two"
d(CVErr(xlErrValue)) = "Excel #VALUE!"
Set d(101) = New Collection

You can also use the VBA Collection object if your needs are simpler and you just want string keys.

I don't know if either actually hashes on anything, so you might want to dig further if you need hashtable-like performance. (EDIT: Scripting.Dictionary does use a hash table internally.)

How to acces external json file objects in vue.js app

I have recently started working on a project using Vue JS, JSON Schema. I am trying to access nested JSON Objects from a JSON Schema file in the Vue app. I tried the below code and now I can load different JSON objects inside different Vue template tags. In the script tag add the below code

import  {JsonObject1name, JsonObject2name} from 'your Json file path';

Now you can access JsonObject1,2 names in data section of export default part as below:

data: () => ({ 
  
  schema: JsonObject1name,
  schema1: JsonObject2name,   
  
  model: {} 
}),

Now you can load the schema, schema1 data inside Vue template according to your requirement. See below code for example :

      <SchemaForm id="unique name representing your Json object1" class="form"  v-model="model" :schema="schema" :components="components">
      </SchemaForm>  

      <SchemaForm id="unique name representing your Json object2" class="form" v-model="model" :schema="schema1" :components="components">
      </SchemaForm>

SchemaForm is the local variable name for @formSchema/native library. I have implemented the data of different JSON objects through forms in different CSS tabs.

I hope this answer helps someone. I can help if there are any questions.

How to use Oracle ORDER BY and ROWNUM correctly?

An alternate I would suggest in this use case is to use the MAX(t_stamp) to get the latest row ... e.g.

select t.* from raceway_input_labo t
where t.t_stamp = (select max(t_stamp) from raceway_input_labo) 
limit 1

My coding pattern preference (perhaps) - reliable, generally performs at or better than trying to select the 1st row from a sorted list - also the intent is more explicitly readable.
Hope this helps ...

SQLer

How to solve java.lang.NullPointerException error?

Just a shot in the dark(since you did not share the compiler initialization code with us): the way you retrieve the compiler causes the issue. Point your JRE to be inside the JDK as unlike jdk, jre does not provide any tools hence, results in NPE.

how to query child objects in mongodb

Assuming your "states" collection is like:

{"name" : "Spain", "cities" : [ { "name" : "Madrid" }, { "name" : null } ] }
{"name" : "France" }

The query to find states with null cities would be:

db.states.find({"cities.name" : {"$eq" : null, "$exists" : true}});

It is a common mistake to query for nulls as:

db.states.find({"cities.name" : null});

because this query will return all documents lacking the key (in our example it will return Spain and France). So, unless you are sure the key is always present you must check that the key exists as in the first query.

Run jQuery function onclick

You can bind the mouseenter and mouseleave events and jQuery will emulate those where they are not native.

$("div.system_box").on('mouseenter', function(){
    //enter
})
.on('mouseleave', function(){
    //leave
});

fiddle

note: do not use hover as that is deprecated

Is it possible to import a whole directory in sass using @import?

I create a file named __partials__.scss in the same directory of partials

|- __partials__.scss
|- /partials
   |- __header__.scss
   |- __viewport__.scss
   |- ....

In __partials__.scss, I wrote these:

@import "partials/header";
@import "partials/viewport";
@import "partials/footer";
@import "partials/forms";
....

So, when I want import the whole partials, just write @import "partials". If I want import any of them, I can also write @import "partials/header".

Copy a table from one database to another in Postgres

To move a table from database A to database B at your local setup, use the following command:

pg_dump -h localhost -U owner-name -p 5432 -C -t table-name database1 | psql -U owner-name -h localhost -p 5432 database2

How to set a hidden value in Razor

While I would have gone with Piotr's answer (because it's all in one line), I was surprised that your sample is closer to your solution than you think. From what you have, you simply assign the model value before you use the Html helper method.

@{Model.RequiredProperty = "default";}
@Html.HiddenFor(model => model.RequiredProperty)

Prevent row names to be written to file when using write.csv

For completeness, write_csv() from the readr package is faster and never writes row names

# install.packages('readr', dependencies = TRUE)
library(readr)
write_csv(t, "t.csv")

If you need to write big data out, use fwrite() from the data.table package. It's much faster than both write.csv and write_csv

# install.packages('data.table')
library(data.table)
fwrite(t, "t.csv")

Below is a benchmark that Edouard published on his site

microbenchmark(write.csv(data, "baseR_file.csv", row.names = F),
               write_csv(data, "readr_file.csv"),
               fwrite(data, "datatable_file.csv"),
               times = 10, unit = "s")

## Unit: seconds
##                                              expr        min         lq       mean     median         uq        max neval
##  write.csv(data, "baseR_file.csv", row.names = F) 13.8066424 13.8248250 13.9118324 13.8776993 13.9269675 14.3241311    10
##                 write_csv(data, "readr_file.csv")  3.6742610  3.7999409  3.8572456  3.8690681  3.8991995  4.0637453    10
##                fwrite(data, "datatable_file.csv")  0.3976728  0.4014872  0.4097876  0.4061506  0.4159007  0.4355469    10

How to correctly close a feature branch in Mercurial?

EDIT ouch, too late... I know read your comment stating that you want to keep the feature-x changeset around, so the cloning approach here doesn't work.

I'll still let the answer here for it may help others.

If you want to completely get rid of "feature X", because, for example, it didn't work, you can clone. This is one of the method explained in the article and it does work, and it talks specifically about heads.

As far as I understand you have this and want to get rid of the "feature-x" head once and for all:

@    changeset:   7:00a7f69c8335
|\   tag:         tip
| |  parent:      4:31b6f976956b
| |  parent:      2:0a834fa43688
| |  summary:     merge
| |
| | o  changeset:   5:013a3e954cfd
| |/   summary:     Closed branch feature-x
| |
| o  changeset:   4:31b6f976956b
| |  summary:     Changeset2
| |
| o  changeset:   3:5cb34be9e777
| |  parent:      1:1cc843e7f4b5
| |  summary:     Changeset 1
| |
o |  changeset:   2:0a834fa43688
|/   summary:     Changeset C
|
o  changeset:   1:1cc843e7f4b5
|  summary:     Changeset B
|
o  changeset:   0:a9afb25eaede
   summary:     Changeset A

So you do this:

hg clone . ../cleanedrepo --rev 7

And you'll have the following, and you'll see that feature-x is indeed gone:

@    changeset:   5:00a7f69c8335
|\   tag:         tip
| |  parent:      4:31b6f976956b
| |  parent:      2:0a834fa43688
| |  summary:     merge
| |
| o  changeset:   4:31b6f976956b
| |  summary:     Changeset2
| |
| o  changeset:   3:5cb34be9e777
| |  parent:      1:1cc843e7f4b5
| |  summary:     Changeset 1
| |
o |  changeset:   2:0a834fa43688
|/   summary:     Changeset C
|
o  changeset:   1:1cc843e7f4b5
|  summary:     Changeset B
|
o  changeset:   0:a9afb25eaede
   summary:     Changeset A

I may have misunderstood what you wanted but please don't mod down, I took time reproducing your use case : )

Jenkins pipeline how to change to another folder

Use WORKSPACE environment variable to change workspace directory.

If doing using Jenkinsfile, use following code :

dir("${env.WORKSPACE}/aQA"){
    sh "pwd"
}

How can you create multiple cursors in Visual Studio Code

In Visual Studio without mouse: Alt+Shift+{ Arrow }.