Programs & Examples On #Response.filter

How to render an ASP.NET MVC view as a string?

To repeat from a more unknown question, take a look at MvcIntegrationTestFramework.

It makes saves you writing your own helpers to stream result and is proven to work well enough. I'd assume this would be in a test project and as a bonus you would have the other testing capabilities once you've got this setup. Main bother would probably be sorting out the dependency chain.

 private static readonly string mvcAppPath = 
     Path.GetFullPath(AppDomain.CurrentDomain.BaseDirectory 
     + "\\..\\..\\..\\MyMvcApplication");
 private readonly AppHost appHost = new AppHost(mvcAppPath);

    [Test]
    public void Root_Url_Renders_Index_View()
    {
        appHost.SimulateBrowsingSession(browsingSession => {
            RequestResult result = browsingSession.ProcessRequest("");
            Assert.IsTrue(result.ResponseText.Contains("<!DOCTYPE html"));
        });
}

How do you do block comments in YAML?

In Azure Devops browser(pipeline yaml editor),

Ctrl + K + C Comment Block

Ctrl + K + U Uncomment Block

There also a 'Toggle Block Comment' option but this did not work for me. enter image description here

There are other 'wierd' ways too: right click to see 'Command Palette' or F1

enter image description here

Then choose a cursor option. enter image description here

Now it is just a matter of #

or even smarter [Ctrl + k] + [Ctrl + c]

Detach (move) subdirectory into separate Git repository

Check out git_split project at https://github.com/vangorra/git_split

Turn git directories into their very own repositories in their own location. No subtree funny business. This script will take an existing directory in your git repository and turn that directory into an independent repository of its own. Along the way, it will copy over the entire change history for the directory you provided.

./git_split.sh <src_repo> <src_branch> <relative_dir_path> <dest_repo>
        src_repo  - The source repo to pull from.
        src_branch - The branch of the source repo to pull from. (usually master)
        relative_dir_path   - Relative path of the directory in the source repo to split.
        dest_repo - The repo to push to.

Best way to specify whitespace in a String.Split operation

Why dont you use?:

string[] ssizes = myStr.Split(' ', '\t');

Node.js throws "btoa is not defined" error

The 'btoa-atob' module does not export a programmatic interface, it only provides command line utilities.

If you need to convert to Base64 you could do so using Buffer:

console.log(Buffer.from('Hello World!').toString('base64'));

Reverse (assuming the content you're decoding is a utf8 string):

console.log(Buffer.from(b64Encoded, 'base64').toString());

Note: prior to Node v4, use new Buffer rather than Buffer.from.

JSON Structure for List of Objects

The first one is invalid syntax. You cannot have object properties inside a plain array. The second one is right although it is not strict JSON. It's a relaxed form of JSON wherein quotes in string keys are omitted.

This tutorial by Patrick Hunlock, may help to learn about JSON and this site may help to validate JSON.

How can you profile a Python script?

There's a lot of great answers but they either use command line or some external program for profiling and/or sorting the results.

I really missed some way I could use in my IDE (eclipse-PyDev) without touching the command line or installing anything. So here it is.

Profiling without command line

def count():
    from math import sqrt
    for x in range(10**5):
        sqrt(x)

if __name__ == '__main__':
    import cProfile, pstats
    cProfile.run("count()", "{}.profile".format(__file__))
    s = pstats.Stats("{}.profile".format(__file__))
    s.strip_dirs()
    s.sort_stats("time").print_stats(10)

See docs or other answers for more info.

Appending an element to the end of a list in Scala

Lists in Scala are not designed to be modified. In fact, you can't add elements to a Scala List; it's an immutable data structure, like a Java String. What you actually do when you "add an element to a list" in Scala is to create a new List from an existing List. (Source)

Instead of using lists for such use cases, I suggest to either use an ArrayBuffer or a ListBuffer. Those datastructures are designed to have new elements added.

Finally, after all your operations are done, the buffer then can be converted into a list. See the following REPL example:

scala> import scala.collection.mutable.ListBuffer
import scala.collection.mutable.ListBuffer

scala> var fruits = new ListBuffer[String]()
fruits: scala.collection.mutable.ListBuffer[String] = ListBuffer()

scala> fruits += "Apple"
res0: scala.collection.mutable.ListBuffer[String] = ListBuffer(Apple)

scala> fruits += "Banana"
res1: scala.collection.mutable.ListBuffer[String] = ListBuffer(Apple, Banana)

scala> fruits += "Orange"
res2: scala.collection.mutable.ListBuffer[String] = ListBuffer(Apple, Banana, Orange)

scala> val fruitsList = fruits.toList
fruitsList: List[String] = List(Apple, Banana, Orange)

Using SELECT result in another SELECT

You are missing table NewScores, so it can't be found. Just join this table.

If you really want to avoid joining it directly you can replace NewScores.NetScore with SELECT NetScore FROM NewScores WHERE {conditions on which they should be matched}

Dependent DLL is not getting copied to the build output folder in Visual Studio

This is a slight tweak on nvirth's example

internal class DummyClass
{
    private static void Dummy()
    {
        Noop(typeof(AbcDll.AnyClass));
    }
    private static void Noop(Type _) { }
}

How to disable gradle 'offline mode' in android studio?

Gradle is in offline mode, which means that it won't go to the network to resolve dependencies.

Go to Preferences > Gradle and uncheck "Offline work".

How to convert an xml string to a dictionary?

This is a great module that someone created. I've used it several times. http://code.activestate.com/recipes/410469-xml-as-dictionary/

Here is the code from the website just in case the link goes bad.

from xml.etree import cElementTree as ElementTree

class XmlListConfig(list):
    def __init__(self, aList):
        for element in aList:
            if element:
                # treat like dict
                if len(element) == 1 or element[0].tag != element[1].tag:
                    self.append(XmlDictConfig(element))
                # treat like list
                elif element[0].tag == element[1].tag:
                    self.append(XmlListConfig(element))
            elif element.text:
                text = element.text.strip()
                if text:
                    self.append(text)


class XmlDictConfig(dict):
    '''
    Example usage:

    >>> tree = ElementTree.parse('your_file.xml')
    >>> root = tree.getroot()
    >>> xmldict = XmlDictConfig(root)

    Or, if you want to use an XML string:

    >>> root = ElementTree.XML(xml_string)
    >>> xmldict = XmlDictConfig(root)

    And then use xmldict for what it is... a dict.
    '''
    def __init__(self, parent_element):
        if parent_element.items():
            self.update(dict(parent_element.items()))
        for element in parent_element:
            if element:
                # treat like dict - we assume that if the first two tags
                # in a series are different, then they are all different.
                if len(element) == 1 or element[0].tag != element[1].tag:
                    aDict = XmlDictConfig(element)
                # treat like list - we assume that if the first two tags
                # in a series are the same, then the rest are the same.
                else:
                    # here, we put the list in dictionary; the key is the
                    # tag name the list elements all share in common, and
                    # the value is the list itself 
                    aDict = {element[0].tag: XmlListConfig(element)}
                # if the tag has attributes, add those to the dict
                if element.items():
                    aDict.update(dict(element.items()))
                self.update({element.tag: aDict})
            # this assumes that if you've got an attribute in a tag,
            # you won't be having any text. This may or may not be a 
            # good idea -- time will tell. It works for the way we are
            # currently doing XML configuration files...
            elif element.items():
                self.update({element.tag: dict(element.items())})
            # finally, if there are no child tags and no attributes, extract
            # the text
            else:
                self.update({element.tag: element.text})

Example usage:

tree = ElementTree.parse('your_file.xml')
root = tree.getroot()
xmldict = XmlDictConfig(root)

//Or, if you want to use an XML string:

root = ElementTree.XML(xml_string)
xmldict = XmlDictConfig(root)

How do I filter an array with TypeScript in Angular 2?

You need to put your code into ngOnInit and use the this keyword:

ngOnInit() {
  this.booksByStoreID = this.books.filter(
          book => book.store_id === this.store.id);
}

You need ngOnInit because the input store wouldn't be set into the constructor:

ngOnInit is called right after the directive's data-bound properties have been checked for the first time, and before any of its children have been checked. It is invoked only once when the directive is instantiated.

(https://angular.io/docs/ts/latest/api/core/index/OnInit-interface.html)

In your code, the books filtering is directly defined into the class content...

Django DoesNotExist

Nice way to handle not found error in Django.

https://docs.djangoproject.com/en/3.1/topics/http/shortcuts/#get-object-or-404

from django.shortcuts import get_object_or_404

def get_data(request):
    obj = get_object_or_404(Model, pk=1)

Spring MVC - Why not able to use @RequestBody and @RequestParam together

The @RequestBody javadoc states

Annotation indicating a method parameter should be bound to the body of the web request.

It uses registered instances of HttpMessageConverter to deserialize the request body into an object of the annotated parameter type.

And the @RequestParam javadoc states

Annotation which indicates that a method parameter should be bound to a web request parameter.

  1. Spring binds the body of the request to the parameter annotated with @RequestBody.

  2. Spring binds request parameters from the request body (url-encoded parameters) to your method parameter. Spring will use the name of the parameter, ie. name, to map the parameter.

  3. Parameters are resolved in order. The @RequestBody is processed first. Spring will consume all the HttpServletRequest InputStream. When it then tries to resolve the @RequestParam, which is by default required, there is no request parameter in the query string or what remains of the request body, ie. nothing. So it fails with 400 because the request can't be correctly handled by the handler method.

  4. The handler for @RequestParam acts first, reading what it can of the HttpServletRequest InputStream to map the request parameter, ie. the whole query string/url-encoded parameters. It does so and gets the value abc mapped to the parameter name. When the handler for @RequestBody runs, there's nothing left in the request body, so the argument used is the empty string.

  5. The handler for @RequestBody reads the body and binds it to the parameter. The handler for @RequestParam can then get the request parameter from the URL query string.

  6. The handler for @RequestParam reads from both the body and the URL query String. It would usually put them in a Map, but since the parameter is of type String, Spring will serialize the Map as comma separated values. The handler for @RequestBody then, again, has nothing left to read from the body.

GenyMotion Unable to start the Genymotion virtual device

Firewall might be the cause, just try disabling it In my case it was due to the firewall. I tried all these suggestions in the answers and none of them worked for me. Finally I disabled the firewall It worked for me.

How to convert wstring into string?

Here is a worked-out solution based on the other suggestions:

#include <string>
#include <iostream>
#include <clocale>
#include <locale>
#include <vector>

int main() {
  std::setlocale(LC_ALL, "");
  const std::wstring ws = L"hëllö";
  const std::locale locale("");
  typedef std::codecvt<wchar_t, char, std::mbstate_t> converter_type;
  const converter_type& converter = std::use_facet<converter_type>(locale);
  std::vector<char> to(ws.length() * converter.max_length());
  std::mbstate_t state;
  const wchar_t* from_next;
  char* to_next;
  const converter_type::result result = converter.out(state, ws.data(), ws.data() + ws.length(), from_next, &to[0], &to[0] + to.size(), to_next);
  if (result == converter_type::ok or result == converter_type::noconv) {
    const std::string s(&to[0], to_next);
    std::cout <<"std::string =     "<<s<<std::endl;
  }
}

This will usually work for Linux, but will create problems on Windows.

Angular 2: Get Values of Multiple Checked Checkboxes

Since I spent a long time solving a similar problem, I'm answering to share my experience. My problem was the same, to know, getting many checkboxes value after a specified event has been triggered. I tried a lot of solutions but for me the sexiest is using ViewChildren.

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

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

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

Found here: https://stackoverflow.com/a/40165639/4775727

Potential other solutions for ref, there are a lot of similar topic, none of them purpose this solution...:

Center image horizontally within a div

you can align your content using flex box with minimum code

HTML

<div class="image-container">
<img src="https://image.freepik.com/free-vector/modern-abstract-background_1048-1003.jpg" width="100px"> 
</div>

CSS

.image-container{
  width:100%;
  background:green;
  display:flex;

_x000D_
_x000D_
.image-container{_x000D_
  width:100%;_x000D_
  background:green;_x000D_
  display:flex;_x000D_
  justify-content: center;_x000D_
  align-items:center;_x000D_
}
_x000D_
<div class="image-container">_x000D_
<img src="https://image.freepik.com/free-vector/modern-abstract-background_1048-1003.jpg" width="100px"> _x000D_
</div>
_x000D_
_x000D_
_x000D_

js fiddle link https://jsfiddle.net/7un6ku2m/

127 Return code from $?

A shell convention is that a successful executable should exit with the value 0. Anything else can be interpreted as a failure of some sort, on part of bash or the executable you that just ran. See also $PIPESTATUS and the EXIT STATUS section of the bash man page:

   For  the shell’s purposes, a command which exits with a zero exit status has succeeded.  An exit status
   of zero indicates success.  A non-zero exit status indicates failure.  When a command terminates  on  a
   fatal signal N, bash uses the value of 128+N as the exit status.
   If  a command is not found, the child process created to execute it returns a status of 127.  If a com-
   mand is found but is not executable, the return status is 126.

   If a command fails because of an error during expansion or redirection, the exit status is greater than
   zero.

   Shell  builtin  commands  return  a  status of 0 (true) if successful, and non-zero (false) if an error
   occurs while they execute.  All builtins return an exit status of 2 to indicate incorrect usage.

   Bash itself returns the exit status of the last command executed, unless  a  syntax  error  occurs,  in
   which case it exits with a non-zero value.  See also the exit builtin command below.

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

I know the topic is a bit old and seems stale, but anyway I was able to use these options:

    deploy:
      resources:
        limits:
          cpus: '0.001'
          memory: 50M

when using 3.7 version of docker-compose

What helped in my case, was using this command:

docker-compose --compatibility up

--compatibility flag stands for (taken from the documentation):

If set, Compose will attempt to convert deploy keys in v3 files to their non-Swarm equivalent

Think it's great, that I don't have to revert my docker-compose file back to v2.

Best way to add Gradle support to IntelliJ Project

  1. Add build.gradle in your project's root directory.

  2. Then just File -> Invalidate Caches / Restart

Here is a basic build.gradle for Java projects:

plugins {
    id 'java'
}

sourceCompatibility = '1.8'
targetCompatibility = '1.8'
version = '1.2.1'

Using Python, how can I access a shared folder on windows network?

Use forward slashes to specify the UNC Path:

open('//HOST/share/path/to/file')

(if your Python client code is also running under Windows)

Deep copy vs Shallow Copy

Deep copy literally performs a deep copy. It means, that if your class has some fields that are references, their values will be copied, not references themselves. If, for example you have two instances of a class, A & B with fields of reference type, and perform a deep copy, changing a value of that field in A won't affect a value in B. And vise-versa. Things are different with shallow copy, because only references are copied, therefore, changing this field in a copied object would affect the original object.

What type of a copy does a copy constructor does?

It is implementation - dependent. This means that there are no strict rules about that, you can implement it like a deep copy or shallow copy, however as far as i know it is a common practice to implement a deep copy in a copy constructor. A default copy constructor performs a shallow copy though.

Set a border around a StackPanel.

What about this one :

<DockPanel Margin="8">
    <Border CornerRadius="6" BorderBrush="Gray" Background="LightGray" BorderThickness="2" DockPanel.Dock="Top">
        <StackPanel Orientation="Horizontal">
            <TextBlock FontSize="14" Padding="0 0 8 0" HorizontalAlignment="Center" VerticalAlignment="Center">Search:</TextBlock>
            <TextBox x:Name="txtSearchTerm" HorizontalAlignment="Center" VerticalAlignment="Center" />
            <Image Source="lock.png" Width="32" Height="32" HorizontalAlignment="Center" VerticalAlignment="Center" />            
        </StackPanel>
    </Border>
    <StackPanel Orientation="Horizontal" DockPanel.Dock="Bottom" Height="25" />
</DockPanel>

Full-screen iframe with a height of 100%

Additional to the answer of Akshit Soota: it is importand to explicitly set the height of each parent element, also of the table and column if any:

<body style="margin: 0px; padding:0px; height: 100%; overflow:hidden; ">
<form id="form1" runat="server" style=" height: 100%">
<div style=" height: 100%">


    <table style="width: 100%; height: 100%" cellspacing="0"  cellpadding="0">
        <tr>
            <td valign="top" align="left" height="100%">
                <iframe style="overflow:hidden;height:100%;width:100%;margin: 0px; padding:0px;" 
                        width="100%" height="100%" frameborder="0" scrolling="no"
                        src="http://www.youraddress.com" ></iframe> 
            </td>

Add a CSS class to <%= f.submit %>

<%= f.submit 'name of button here', :class => 'submit_class_name_here' %>

This should do. If you're getting an error, chances are that you're not supplying the name.

Alternatively, you can style the button without a class:

form#form_id_here input[type=submit]

Try that, as well.

How to change default Anaconda python environment

Create a shortcut of anaconda prompt onto desktop or taskbar, and then in the properties of that shortcut make sure u modify the last path in "Target:" to the path of ur environment:

C:\Users\BenBouali\Anaconda3\ WILL CHANGE INTO C:\Users\BenBouali\Anaconda3\envs\tensorflow-gpu

preview

and this way u can use that shortcut to open a certain environment when clicking it, you can add it to ur path too and now you'll be able to run it from windows run box by just typing in the name of the shortcut.

How to unbind a listener that is calling event.preventDefault() (using jQuery)?

In my case:

$('#some_link').click(function(event){
    event.preventDefault();
});

$('#some_link').unbind('click'); worked as the only method to restore the default action.

As seen over here: https://stackoverflow.com/a/1673570/211514

Fastest way to copy a file in Node.js

Well, usually it is good to avoid asynchronous file operations. Here is the short (i.e. no error handling) sync example:

var fs = require('fs');
fs.writeFileSync(targetFile, fs.readFileSync(sourceFile));

Reading a JSP variable from JavaScript

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <script 
src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"> 

    <title>JSP Page</title>
    <script>
       $(document).ready(function(){
          <% String name = "phuongmychi.github.io" ;%> // jsp vari
         var name = "<%=name %>" // call var to js
         $("#id").html(name); //output to html

       });
    </script>
</head>
<body>
    <h1 id='id'>!</h1>
</body>

Simple search MySQL database using php

You need to use $_POST not $_post.

"pip install json" fails on Ubuntu

While it's true that json is a built-in module, I also found that on an Ubuntu system with python-minimal installed, you DO have python but you can't do import json. And then I understand that you would try to install the module using pip!

If you have python-minimal you'll get a version of python with less modules than when you'd typically compile python yourself, and one of the modules you'll be missing is the json module. The solution is to install an additional package, called libpython2.7-stdlib, to install all 'default' python libraries.

sudo apt install libpython2.7-stdlib

And then you can do import json in python and it would work!

Why does writeObject throw java.io.NotSerializableException and how do I fix it?

java.io.NotSerializableException can occur when you serialize an inner class instance because:

serializing such an inner class instance will result in serialization of its associated outer class instance as well

Serialization of inner classes (i.e., nested classes that are not static member classes), including local and anonymous classes, is strongly discouraged

Ref: The Serializable Interface

Print a file's last modified date in Bash

On OS X, I like my date to be in the format of YYYY-MM-DD HH:MM in the output for the file.

So to specify a file I would use:

stat -f "%Sm" -t "%Y-%m-%d %H:%M" [filename]

If I want to run it on a range of files, I can do something like this:

#!/usr/bin/env bash
for i in /var/log/*.out; do
  stat -f "%Sm" -t "%Y-%m-%d %H:%M" "$i"
done

This example will print out the last time I ran the sudo periodic daily weekly monthly command as it references the log files.


To add the filenames under each date, I would run the following instead:

#!/usr/bin/env bash
for i in /var/log/*.out; do
  stat -f "%Sm" -t "%Y-%m-%d %H:%M" "$i"
  echo "$i"
done

The output would was the following:

2016-40-01 16:40
/var/log/daily.out
2016-40-01 16:40
/var/log/monthly.out
2016-40-01 16:40
/var/log/weekly.out

Unfortunately I'm not sure how to prevent the line break and keep the file name appended to the end of the date without adding more lines to the script.


PS - I use #!/usr/bin/env bash as I'm a Python user by day, and have different versions of bash installed on my system instead of #!/bin/bash

How to 'grep' a continuous stream?

This one command workes for me (Suse):

mail-srv:/var/log # tail -f /var/log/mail.info |grep --line-buffered LOGIN  >> logins_to_mail

collecting logins to mail service

How to get the employees with their managers

This is a classic self-join, try the following:

SELECT e.ename, e.empno, m.ename as manager, e.mgr
FROM
    emp e, emp m
WHERE e.mgr = m.empno

And if you want to include the president which has no manager then instead of an inner join use an outer join in Oracle syntax:

SELECT e.ename, e.empno, m.ename as manager, e.mgr
FROM
    emp e, emp m
WHERE e.mgr = m.empno(+)

Or in ANSI SQL syntax:

SELECT e.ename, e.empno, m.ename as manager, e.mgr
FROM
    emp e
    LEFT OUTER JOIN emp m
        ON e.mgr = m.empno

Bash: infinite sleep (infinite blocking)

This approach will not consume any resources for keeping process alive.

while :; do sleep 1; done & kill -STOP $! && wait $!

Breakdown

  • while :; do sleep 1; done & Creates a dummy process in background
  • kill -STOP $! Stops the background process
  • wait $! Wait for the background process, this will be blocking forever, cause background process was stopped before

What does upstream mean in nginx?

It's used for proxying requests to other servers.

An example from http://wiki.nginx.org/LoadBalanceExample is:

http {
  upstream myproject {
    server 127.0.0.1:8000 weight=3;
    server 127.0.0.1:8001;
    server 127.0.0.1:8002;    
    server 127.0.0.1:8003;
  }

  server {
    listen 80;
    server_name www.domain.com;
    location / {
      proxy_pass http://myproject;
    }
  }
}

This means all requests for / go to the any of the servers listed under upstream XXX, with a preference for port 8000.

Best way to check for IE less than 9 in JavaScript without library

I liked Mike Lewis' answer but the code did not pass jslint and I could not understand the funky while loop. My use case is to put up a browser not supported message if less than or equal to IE8.

Here is a jslint free version based on Mike Lewis':

/*jslint browser: true */
/*global jQuery */
(function () {
    "use strict";
    var browserNotSupported = (function () {
        var div = document.createElement('DIV');
        // http://msdn.microsoft.com/en-us/library/ms537512(v=vs.85).aspx
        div.innerHTML = '<!--[if lte IE 8]><I></I><![endif]-->';
        return div.getElementsByTagName('I').length > 0;
    }());
    if (browserNotSupported) {
        jQuery("html").addClass("browserNotSupported").data("browserNotSupported", browserNotSupported);
    }
}());

Java JTextField with input hint

Here is a simple way that looks good in any L&F:

public class HintTextField extends JTextField {
    public HintTextField(String hint) {
        _hint = hint;
    }
    @Override
    public void paint(Graphics g) {
        super.paint(g);
        if (getText().length() == 0) {
            int h = getHeight();
            ((Graphics2D)g).setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
            Insets ins = getInsets();
            FontMetrics fm = g.getFontMetrics();
            int c0 = getBackground().getRGB();
            int c1 = getForeground().getRGB();
            int m = 0xfefefefe;
            int c2 = ((c0 & m) >>> 1) + ((c1 & m) >>> 1);
            g.setColor(new Color(c2, true));
            g.drawString(_hint, ins.left, h / 2 + fm.getAscent() / 2 - 2);
        }
    }
    private final String _hint;
}

What is for Python what 'explode' is for PHP?

The alternative for explode in php is split.

The first parameter is the delimiter, the second parameter the maximum number splits. The parts are returned without the delimiter present (except possibly the last part). When the delimiter is None, all whitespace is matched. This is the default.

>>> "Rajasekar SP".split()
['Rajasekar', 'SP']

>>> "Rajasekar SP".split('a',2)
['R','j','sekar SP']

presenting ViewController with NavigationViewController swift

The accepted answer is great. This is not answer, but just an illustration of the issue.

I present a viewController like this:

inside vc1:

func showVC2() {
    if let navController = self.navigationController{
        navController.present(vc2, animated: true)
    }
}

inside vc2:

func returnFromVC2() {
    if let navController = self.navigationController {
        navController.popViewController(animated: true)
    }else{
        print("navigationController is nil") <-- I was reaching here!
    }
}

As 'stefandouganhyde' has said: "it is not contained by your UINavigationController or any other"

new solution:

func returnFromVC2() {
    dismiss(animated: true, completion: nil)
}

How to set the maximum memory usage for JVM?

The answer above is kind of correct, you can't gracefully control how much native memory a java process allocates. It depends on what your application is doing.

That said, depending on platform, you may be able to do use some mechanism, ulimit for example, to limit the size of a java or any other process.

Just don't expect it to fail gracefully if it hits that limit. Native memory allocation failures are much harder to handle than allocation failures on the java heap. There's a fairly good chance the application will crash but depending on how critical it is to the system to keep the process size down that might still suit you.

Alter column, add default constraint

Try this

alter table TableName 
 add constraint df_ConstraintNAme 
 default getutcdate() for [Date]

example

create table bla (id int)

alter table bla add constraint dt_bla default 1 for id



insert bla default values

select * from bla

also make sure you name the default constraint..it will be a pain in the neck to drop it later because it will have one of those crazy system generated names...see also How To Name Default Constraints And How To Drop Default Constraint Without A Name In SQL Server

LINQ equivalent of foreach for IEnumerable<T>

So many answers, yet ALL fail to pinpoint one very significant problem with a custom generic ForEach extension: Performance! And more specifically, memory usage and GC.

Consider the sample below. Targeting .NET Framework 4.7.2 or .NET Core 3.1.401, configuration is Release and platform is Any CPU.

public static class Enumerables
{
    public static void ForEach<T>(this IEnumerable<T> @this, Action<T> action)
    {
        foreach (T item in @this)
        {
            action(item);
        }
    }
}

class Program
{
    private static void NoOp(int value) {}

    static void Main(string[] args)
    {
        var list = Enumerable.Range(0, 10).ToList();
        for (int i = 0; i < 1000000; i++)
        {
            // WithLinq(list);
            // WithoutLinqNoGood(list);
            WithoutLinq(list);
        }
    }

    private static void WithoutLinq(List<int> list)
    {
        foreach (var item in list)
        {
            NoOp(item);
        }
    }

    private static void WithLinq(IEnumerable<int> list) => list.ForEach(NoOp);

    private static void WithoutLinqNoGood(IEnumerable<int> enumerable)
    {
        foreach (var item in enumerable)
        {
            NoOp(item);
        }
    }
}

At a first glance, all three variants should perform equally well. However, when the ForEach extension method is called many, many times, you will end up with garbage that implies a costly GC. In fact, having this ForEach extension method on a hot path has been proven to totally kill performance in our loop-intensive application.

Similarly, the weekly typed foreach loop will also produce garbage, but it will still be faster and less memory-intensive than the ForEach extension (which also suffers from a delegate allocation).

Strongly typed foreach: Memory usage

No allocations. No GC

Weekly typed foreach: Memory usage

enter image description here

ForEach extension: Memory usage

Lots of allocations. Heavy GC.

Analysis

For a strongly typed foreach the compiler is able to use any optimized enumerator (e.g. value based) of a class, whereas a generic ForEach extension must fall back to a generic enumerator which will be allocated on each run. Furthermore, the actual delegate will also imply an additional allocation.

You would get similar bad results with the WithoutLinqNoGood method. There, the argument is of type IEnumerable<int> instead of List<int> implying the same type of enumerator allocation.

Below are the relevant differences in IL. A value based enumerator is certainly preferable!

IL_0001:  callvirt   instance class
          [mscorlib]System.Collections.Generic.IEnumerator`1<!0> 
          class [mscorlib]System.Collections.Generic.IEnumerable`1<!!T>::GetEnumerator()

vs

IL_0001:  callvirt   instance valuetype
          [mscorlib]System.Collections.Generic.List`1/Enumerator<!0>
          class [mscorlib]System.Collections.Generic.List`1<int32>::GetEnumerator()

Conclusion

The OP asked how to call ForEach() on an IEnumerable<T>. The original answer clearly shows how it can be done. Sure you can do it, but then again; my answer clearly shows that you shouldn't.

Verified the same behavior when targeting .NET Core 3.1.401 (compiling with Visual Studio 16.7.2).

Web API Put Request generates an Http 405 Method Not Allowed error

I'm running an ASP.NET MVC 5 application on IIS 8.5. I tried all the variations posted here, and this is what my web.config looks like:

<system.webServer>
    <modules runAllManagedModulesForAllRequests="true">
        <remove name="WebDAVModule"/> <!-- add this -->
    </modules>  
    <handlers>      
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" />
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" />
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="WebDAV" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers> 
</system.webServer>

I couldn't uninstall WebDav from my Server because I didn't have admin privileges. Also, sometimes I was getting the method not allowed on .css and .js files. In the end, with the configuration above set up everything started working again.

Maven skip tests

I have another approach for Intellij users, and it is working very fine for me:

  1. Click on the "Skip Test" button

enter image description here

  1. Hold the "CTRL" button
  2. Select "clean" and "install"

enter image description here

  1. Click on the "Run" button in the maven pannel

enter image description here

Capturing image from webcam in java?

I have used JMF on a videoconference application and it worked well on two laptops: one with integrated webcam and another with an old USB webcam. It requires JMF being installed and configured before-hand, but once you're done you can access the hardware via Java code fairly easily.

MySQL: How to set the Primary Key on phpMyAdmin?

MySQL can index the first x characters of a column,but a TEXT type is of variable length so mysql cant assure the uniqueness of the column.If you still want text column,use VARCHAR.

Catch a thread's exception in the caller thread in Python

Wrap Thread with exception storage.

import threading
import sys
class ExcThread(threading.Thread):

    def __init__(self, target, args = None):
        self.args = args if args else []
        self.target = target
        self.exc = None
        threading.Thread.__init__(self)

    def run(self):
        try:
            self.target(*self.args)
            raise Exception('An error occured here.')
        except Exception:
            self.exc=sys.exc_info()

def main():
    def hello(name):
        print(!"Hello, {name}!")
    thread_obj = ExcThread(target=hello, args=("Jack"))
    thread_obj.start()

    thread_obj.join()
    exc = thread_obj.exc
    if exc:
        exc_type, exc_obj, exc_trace = exc
        print(exc_type, ':',exc_obj, ":", exc_trace)

main()

CSS background image to fit height, width should auto-scale in proportion

I just had the same issue and this helped me:

html {
    height: auto;
    min-height: 100%;
    background-size:cover;
}

using lodash .groupBy. how to add your own keys for grouped output?

Thanks @thefourtheye, your code greatly helped. I created a generic function from your solution using the version 4.5.0 of Lodash.

function groupBy(dataToGroupOn, fieldNameToGroupOn, fieldNameForGroupName, fieldNameForChildren) {
            var result = _.chain(dataToGroupOn)
             .groupBy(fieldNameToGroupOn)
             .toPairs()
             .map(function (currentItem) {
                 return _.zipObject([fieldNameForGroupName, fieldNameForChildren], currentItem);
             })
             .value();
            return result;
        }

To use it:

var result = groupBy(data, 'color', 'colorId', 'users');

Here is the updated fiddler;

https://jsfiddle.net/sc2L9dby/

What is meant with "const" at end of function declaration?

I always find it conceptually easier to think of that you are making the this pointer const (which is pretty much what it does).

Make cross-domain ajax JSONP request with jQuery

You need to use the ajax-cross-origin plugin: http://www.ajax-cross-origin.com/

Just add the option crossOrigin: true

$.ajax({
    crossOrigin: true,
    url: url,
    success: function(data) {
        console.log(data);
    }
});

Combining two Series into a DataFrame in pandas

Example code:

a = pd.Series([1,2,3,4], index=[7,2,8,9])
b = pd.Series([5,6,7,8], index=[7,2,8,9])
data = pd.DataFrame({'a': a,'b':b, 'idx_col':a.index})

Pandas allows you to create a DataFrame from a dict with Series as the values and the column names as the keys. When it finds a Series as a value, it uses the Series index as part of the DataFrame index. This data alignment is one of the main perks of Pandas. Consequently, unless you have other needs, the freshly created DataFrame has duplicated value. In the above example, data['idx_col'] has the same data as data.index.

How to add element in Python to the end of list using list.insert?

list.insert with any index >= len(of_the_list) places the value at the end of list. It behaves like append

Python 3.7.4
>>>lst=[10,20,30]
>>>lst.insert(len(lst), 101)
>>>lst
[10, 20, 30, 101]
>>>lst.insert(len(lst)+50, 202)
>>>lst
[10, 20, 30, 101, 202]

Time complexity, append O(1), insert O(n)

Check if a String is in an ArrayList of Strings

temp = bankAccNos.contains(no) ? 1 : 2;

How do I use Join-Path to combine more than two strings into a file path?

You can use the .NET Path class:

[IO.Path]::Combine('C:\', 'Foo', 'Bar')

first-child and last-child with IE8

If your table is only 2 columns across, you can easily reach the second td with the adjacent sibling selector, which IE8 does support along with :first-child:

.editor td:first-child
{
    width: 150px; 
}

.editor td:first-child + td input,
.editor td:first-child + td textarea
{
    width: 500px;
    padding: 3px 5px 5px 5px;
    border: 1px solid #CCC; 
}

Otherwise, you'll have to use a JS selector library like jQuery, or manually add a class to the last td, as suggested by James Allardice.

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/CollegeWebsite]]

You have a version conflict, please verify whether compiled version and JVM of Tomcat version are same. you can do it by examining tomcat startup .bat , looking for JAVA_HOME

How to add an image to an svg container using D3.js

My team also wanted to add images inside d3-drawn circles, and came up with the following (fiddle):

index.html:

<!doctype html>
<html>
<head>
  <link rel="stylesheet" type="text/css" href="timeline.css">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.js"></script>
  <script src="https://code.jquery.com/jquery-2.2.4.js"
    integrity="sha256-iT6Q9iMJYuQiMWNd9lDyBUStIq/8PuOW33aOqmvFpqI="
    crossorigin="anonymous"></script>
  <script src="./timeline.js"></script>
</head>
  <body>
    <div class="timeline"></div>
  </body>
</html>

timeline.css:

.axis path,
.axis line,
.tick line,
.line {
  fill: none;
  stroke: #000000;
  stroke-width: 1px;
}

timeline.js:

// container target
var elem = ".timeline";

var props = {
  width: 1000,
  height: 600,
  class: "timeline-point",

  // margins
  marginTop: 100,
  marginRight: 40,
  marginBottom: 100,
  marginLeft: 60,

  // data inputs
  data: [
    {
      x: 10,
      y: 20,
      key: "a",
      image: "https://unsplash.it/300/300",
      id: "a"
    },
    {
      x: 20,
      y: 10,
      key: "a",
      image: "https://unsplash.it/300/300",
      id: "b"
    },
    {
      x: 60,
      y: 30,
      key: "a",
      image: "https://unsplash.it/300/300",
      id: "c"
    },
    {
      x: 40,
      y: 30,
      key: "a",
      image: "https://unsplash.it/300/300",
      id: "d"
    },
    {
      x: 50,
      y: 70,
      key: "a",
      image: "https://unsplash.it/300/300",
      id: "e"
    },
    {
      x: 30,
      y: 50,
      key: "a",
      image: "https://unsplash.it/300/300",
      id: "f"
    },
    {
      x: 50,
      y: 60,
      key: "a",
      image: "https://unsplash.it/300/300",
      id: "g"
    }
  ],

  // y label
  yLabel: "Y label",
  yLabelLength: 50,

  // axis ticks
  xTicks: 10,
  yTicks: 10

}

// component start
var Timeline = {};

/***
*
* Create the svg canvas on which the chart will be rendered
*
***/

Timeline.create = function(elem, props) {

  // build the chart foundation
  var svg = d3.select(elem).append('svg')
      .attr('width', props.width)
      .attr('height', props.height);

  var g = svg.append('g')
      .attr('class', 'point-container')
      .attr("transform",
              "translate(" + props.marginLeft + "," + props.marginTop + ")");

  var g = svg.append('g')
      .attr('class', 'line-container')
      .attr("transform", 
              "translate(" + props.marginLeft + "," + props.marginTop + ")");

  var xAxis = g.append('g')
    .attr("class", "x axis")
    .attr("transform", "translate(0," + (props.height - props.marginTop - props.marginBottom) + ")");

  var yAxis = g.append('g')
    .attr("class", "y axis");

  svg.append("text")
    .attr("class", "y label")
    .attr("text-anchor", "end")
    .attr("y", 1)
    .attr("x", 0 - ((props.height - props.yLabelLength)/2) )
    .attr("dy", ".75em")
    .attr("transform", "rotate(-90)")
    .text(props.yLabel);

  // add placeholders for the axes
  this.update(elem, props);
};

/***
*
* Update the svg scales and lines given new data
*
***/

Timeline.update = function(elem, props) {
  var self = this;
  var domain = self.getDomain(props);
  var scales = self.scales(elem, props, domain);

  self.drawPoints(elem, props, scales);
};


/***
*
* Use the range of values in the x,y attributes
* of the incoming data to identify the plot domain
*
***/

Timeline.getDomain = function(props) {
  var domain = {};
  domain.x = props.xDomain || d3.extent(props.data, function(d) { return d.x; });
  domain.y = props.yDomain || d3.extent(props.data, function(d) { return d.y; });
  return domain;
};


/***
*
* Compute the chart scales
*
***/

Timeline.scales = function(elem, props, domain) {

  if (!domain) {
    return null;
  }

  var width = props.width - props.marginRight - props.marginLeft;
  var height = props.height - props.marginTop - props.marginBottom;

  var x = d3.scale.linear()
    .range([0, width])
    .domain(domain.x);

  var y = d3.scale.linear()
    .range([height, 0])
    .domain(domain.y);

  return {x: x, y: y};
};


/***
*
* Create the chart axes
*
***/

Timeline.axes = function(props, scales) {

  var xAxis = d3.svg.axis()
    .scale(scales.x)
    .orient("bottom")
    .ticks(props.xTicks)
    .tickFormat(d3.format("d"));

  var yAxis = d3.svg.axis()
    .scale(scales.y)
    .orient("left")
    .ticks(props.yTicks);

  return {
    xAxis: xAxis,
    yAxis: yAxis
  }
};


/***
*
* Use the general update pattern to draw the points
*
***/

Timeline.drawPoints = function(elem, props, scales, prevScales, dispatcher) {
  var g = d3.select(elem).selectAll('.point-container');
  var color = d3.scale.category10();

  // add images
  var image = g.selectAll('.image')
    .data(props.data)

  image.enter()
    .append("pattern")
    .attr("id", function(d) {return d.id})
    .attr("class", "svg-image")
    .attr("x", "0")
    .attr("y", "0")
    .attr("height", "70px")
    .attr("width", "70px")
    .append("image")
      .attr("x", "0")
      .attr("y", "0")
      .attr("height", "70px")
      .attr("width", "70px")
      .attr("xlink:href", function(d) {return d.image})

  var point = g.selectAll('.point')
    .data(props.data);

  // enter
  point.enter()
    .append("circle")
      .attr("class", "point")
      .on('mouseover', function(d) {
        d3.select(elem).selectAll(".point").classed("active", false);
        d3.select(this).classed("active", true);
        if (props.onMouseover) {
          props.onMouseover(d)
        };
      })
      .on('mouseout', function(d) {
        if (props.onMouseout) {
          props.onMouseout(d)
        };
      })

  // enter and update
  point.transition()
    .duration(1000)
    .attr("cx", function(d) {
      return scales.x(d.x); 
    })
    .attr("cy", function(d) { 
      return scales.y(d.y); 
    })
    .attr("r", 30)
    .style("stroke", function(d) {
      if (props.pointStroke) {
        return d.color = props.pointStroke;
      } else {
        return d.color = color(d.key);
      }
    })
    .style("fill", function(d) {
      if (d.image) {
        return ("url(#" + d.id + ")");
      }

      if (props.pointFill) {
        return d.color = props.pointFill;
      } else {
        return d.color = color(d.key);
      }
    });

  // exit
  point.exit()
    .remove();

  // update the axes
  var axes = this.axes(props, scales);
  d3.select(elem).selectAll('g.x.axis')
    .transition()
    .duration(1000)
    .call(axes.xAxis);

  d3.select(elem).selectAll('g.y.axis')
    .transition()
    .duration(1000)
    .call(axes.yAxis);
};


$(document).ready(function() {
  Timeline.create(elem, props);
})

How to generate serial version UID in Intellij

Without any plugins:

You just need to enable highlight: (Idea v.2016, 2017 and 2018, previous versions may have same or similar settings)

File -> Settings -> Editor -> Inspections -> Java -> Serialization issues -> Serializable class without 'serialVersionUID' - set flag and click 'OK'. (For Macs, Settings is under IntelliJ IDEA -> Preferences...)

Now, if your class implements Serializable, you will see highlight and alt+Enter on class name will ask you to generate private static final long serialVersionUID.

UPD: a faster way to find this setting - you might use hotkey Ctrl+Shift+A (find action), type Serializable class without 'serialVersionUID' - the first is the one.

How to remove all leading zeroes in a string

you can add "+" in your variable,

example :

$numString = "0000001123000";
echo +$numString;

What is Robocopy's "restartable" option?

Restartable mode (/Z) has to do with a partially-copied file. With this option, should the copy be interrupted while any particular file is partially copied, the next execution of robocopy can pick up where it left off rather than re-copying the entire file.

That option could be useful when copying very large files over a potentially unstable connection.

Backup mode (/B) has to do with how robocopy reads files from the source system. It allows the copying of files on which you might otherwise get an access denied error on either the file itself or while trying to copy the file's attributes/permissions. You do need to be running in an Administrator context or otherwise have backup rights to use this flag.

How to implement a tree data-structure in Java?

What about this?

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;

/**
  * @author [email protected] (Yohann Coppel)
  * 
  * @param <T>
  *          Object's type in the tree.
*/
public class Tree<T> {

  private T head;

  private ArrayList<Tree<T>> leafs = new ArrayList<Tree<T>>();

  private Tree<T> parent = null;

  private HashMap<T, Tree<T>> locate = new HashMap<T, Tree<T>>();

  public Tree(T head) {
    this.head = head;
    locate.put(head, this);
  }

  public void addLeaf(T root, T leaf) {
    if (locate.containsKey(root)) {
      locate.get(root).addLeaf(leaf);
    } else {
      addLeaf(root).addLeaf(leaf);
    }
  }

  public Tree<T> addLeaf(T leaf) {
    Tree<T> t = new Tree<T>(leaf);
    leafs.add(t);
    t.parent = this;
    t.locate = this.locate;
    locate.put(leaf, t);
    return t;
  }

  public Tree<T> setAsParent(T parentRoot) {
    Tree<T> t = new Tree<T>(parentRoot);
    t.leafs.add(this);
    this.parent = t;
    t.locate = this.locate;
    t.locate.put(head, this);
    t.locate.put(parentRoot, t);
    return t;
  }

  public T getHead() {
    return head;
  }

  public Tree<T> getTree(T element) {
    return locate.get(element);
  }

  public Tree<T> getParent() {
    return parent;
  }

  public Collection<T> getSuccessors(T root) {
    Collection<T> successors = new ArrayList<T>();
    Tree<T> tree = getTree(root);
    if (null != tree) {
      for (Tree<T> leaf : tree.leafs) {
        successors.add(leaf.head);
      }
    }
    return successors;
  }

  public Collection<Tree<T>> getSubTrees() {
    return leafs;
  }

  public static <T> Collection<T> getSuccessors(T of, Collection<Tree<T>> in) {
    for (Tree<T> tree : in) {
      if (tree.locate.containsKey(of)) {
        return tree.getSuccessors(of);
      }
    }
    return new ArrayList<T>();
  }

  @Override
  public String toString() {
    return printTree(0);
  }

  private static final int indent = 2;

  private String printTree(int increment) {
    String s = "";
    String inc = "";
    for (int i = 0; i < increment; ++i) {
      inc = inc + " ";
    }
    s = inc + head;
    for (Tree<T> child : leafs) {
      s += "\n" + child.printTree(increment + indent);
    }
    return s;
  }
}

How to compare only Date without Time in DateTime types in Linq to SQL with Entity Framework?

If you're using Entity Framework < v6.0, then use EntityFunctions.TruncateTime If you're using Entity Framework >= v6.0, then use DbFunctions.TruncateTime

Use either (based on your EF version) around any DateTime class property you want to use inside your Linq query

Example

var list = db.Cars.Where(c=> DbFunctions.TruncateTime(c.CreatedDate) 
                                       >= DbFunctions.TruncateTime(DateTime.UtcNow));

Scala vs. Groovy vs. Clojure

Groovy is a dynamically typed language, whose syntax is very close to Java, with a number of syntax improvements that allow for lighter code and less boilerplate. It can run through an interpreter as well as being compiled, which makes it good for fast prototyping, scripts, and learning dynamic languages without having to learn a new syntax (assuming you know Java). As of Groovy 2.0, it also has growing support for static compilation. Groovy supports closures and has support for programming in a somewhat functional style, although it's still fairly far from the traditional definition of functional programming.

Clojure is a dialect of Lisp with a few advanced features like Software Transactional Memory. If you like Lisp and would like to use something like it under the JVM, Clojure is for you. It's possibly the most functional language running on the JVM, and certainly the most famous one. Also, it has a stronger emphasis on immutability than other Lisp dialects, which takes it closer to the heart of functional language enthusiasts.

Scala is a fully object oriented language, more so than Java, with one of the most advanced type systems available on non-research languages, and certainly the most advanced type system on the JVM. It also combines many concepts and features of functional languages, without compromising the object orientation, but its compromise on functional language characteristics put off some enthusiasts of the latter.

Groovy has good acceptance and a popular web framework in Grails. It also powers the Gradle build system, which is becoming a popular alternative to Maven. I personally think it is a language with limited utility, particularly as Jython and JRuby start making inroads on the JVM-land, compared to the others.

Clojure, even discounting some very interesting features, has a strong appeal just by being a Lisp dialect on JVM. It might limit its popularity, granted, but I expect it will have loyal community around it for a long time.

Scala can compete directly with Java, and give it a run for its money on almost all aspects. It can't compete in popularity at the moment, of course, and the lack of a strong corporate backing may hinder its acceptance on corporate environments. It's also a much more dynamic language than Java, in the sense of how the language evolves. From the perspective of the language, that's a good thing. From the perspective of users who plan on having thousands of lines of code written in it, not so.

As a final disclosure, I'm very familiar with Scala, and only acquainted with the other two.

How to sort an array of objects with jquery or javascript

data.sort(function(a,b) 
{
   return a.val - b.val;
});

Adding images or videos to iPhone Simulator

Method 1 (Easiest Way): If you have your image on Mac

You can drag an image from the Finder on your Mac to Simulator, and it is saved to the Saved Photos album.

Method 2: If its on any URL

To save an image from a webpage to the Photos app

  1. Place the pointer on the image you want to save, and hold down the mouse button or trackpad.
  2. When the menu appears, click Save Image to save the image to the Photos app in an iOS simulator.
  3. The image is saved to the Saved Photos album in the Photos app.

Incase someone looking for Apple Documentation regarding Copying and Pasting in Simulator. Save Image from Safari

Joining pandas dataframes by column names

you need to make county_ID as index for the right frame:

frame_2.join ( frame_1.set_index( [ 'county_ID' ], verify_integrity=True ),
               on=[ 'countyid' ], how='left' )

for your information, in pandas left join breaks when the right frame has non unique values on the joining column. see this bug.

so you need to verify integrity before joining by , verify_integrity=True

How to use Bootstrap 4 in ASP.NET Core

Use nmp configuration file (add it to your web project) then add the needed packages in the same way we did using bower.json and save. Visual studio will download and install it. You'll find the package the under the nmp node of your project.

Making an image act like a button

It sounds like you want an image button:

<input type="image" src="logg.png" name="saveForm" class="btTxt submit" id="saveForm" />

Alternatively, you can use CSS to make the existing submit button use your image as its background.

In any case, you don't want a separate <img /> element on the page.

A Java collection of value pairs? (tuples?)

The Pair class is one of those "gimme" generics examples that is easy enough to write on your own. For example, off the top of my head:

public class Pair<L,R> {

  private final L left;
  private final R right;

  public Pair(L left, R right) {
    assert left != null;
    assert right != null;

    this.left = left;
    this.right = right;
  }

  public L getLeft() { return left; }
  public R getRight() { return right; }

  @Override
  public int hashCode() { return left.hashCode() ^ right.hashCode(); }

  @Override
  public boolean equals(Object o) {
    if (!(o instanceof Pair)) return false;
    Pair pairo = (Pair) o;
    return this.left.equals(pairo.getLeft()) &&
           this.right.equals(pairo.getRight());
  }

}

And yes, this exists in multiple places on the Net, with varying degrees of completeness and feature. (My example above is intended to be immutable.)

How to detect scroll position of page using jQuery

$(window).scroll( function() { 
 var scrolled_val = $(document).scrollTop().valueOf();
 alert(scrolled_val+ ' = scroll value');
});

This is another way of getting the value of scroll.

JavaFX - create custom button with image

There are a few different ways to accomplish this, I'll outline my favourites.

Use a ToggleButton and apply a custom style to it. I suggest this because your required control is "like a toggle button" but just looks different from the default toggle button styling.

My preferred method is to define a graphic for the button in css:

.toggle-button {
  -fx-graphic: url('http://icons.iconarchive.com/icons/aha-soft/desktop-buffet/128/Pizza-icon.png');
}

.toggle-button:selected {
  -fx-graphic: url('http://icons.iconarchive.com/icons/aha-soft/desktop-buffet/128/Piece-of-cake-icon.png');
}

OR use the attached css to define a background image.

// file imagetogglebutton.css deployed in the same package as ToggleButtonImage.class
.toggle-button {
  -fx-background-image: url('http://icons.iconarchive.com/icons/aha-soft/desktop-buffet/128/Pizza-icon.png');
  -fx-background-repeat: no-repeat;
  -fx-background-position: center;
}

.toggle-button:selected {
  -fx-background-image: url('http://icons.iconarchive.com/icons/aha-soft/desktop-buffet/128/Piece-of-cake-icon.png');
}

I prefer the -fx-graphic specification over the -fx-background-* specifications as the rules for styling background images are tricky and setting the background does not automatically size the button to the image, whereas setting the graphic does.

And some sample code:

import javafx.application.Application;
import javafx.scene.*;
import javafx.scene.control.ToggleButton;
import javafx.scene.layout.StackPaneBuilder;
import javafx.stage.Stage;

public class ToggleButtonImage extends Application {
  public static void main(String[] args) throws Exception { launch(args); }
  @Override public void start(final Stage stage) throws Exception {
    final ToggleButton toggle = new ToggleButton();
    toggle.getStylesheets().add(this.getClass().getResource(
      "imagetogglebutton.css"
    ).toExternalForm());
    toggle.setMinSize(148, 148); toggle.setMaxSize(148, 148);
    stage.setScene(new Scene(
      StackPaneBuilder.create()
        .children(toggle)
        .style("-fx-padding:10; -fx-background-color: cornsilk;")
        .build()
    ));
    stage.show();
  }
}

Some advantages of doing this are:

  1. You get the default toggle button behavior and don't have to re-implement it yourself by adding your own focus styling, mouse and key handlers etc.
  2. If your app gets ported to different platform such as a mobile device, it will work out of the box responding to touch events rather than mouse events, etc.
  3. Your styling is separated from your application logic so it is easier to restyle your application.

An alternate is to not use css and still use a ToggleButton, but set the image graphic in code:

import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.scene.*;
import javafx.scene.control.ToggleButton;
import javafx.scene.image.*;
import javafx.scene.layout.StackPaneBuilder;
import javafx.stage.Stage;

public class ToggleButtonImageViaGraphic extends Application {
  public static void main(String[] args) throws Exception { launch(args); }
  @Override public void start(final Stage stage) throws Exception {
    final ToggleButton toggle      = new ToggleButton();
    final Image        unselected  = new Image(
      "http://icons.iconarchive.com/icons/aha-soft/desktop-buffet/128/Pizza-icon.png"
    );
    final Image        selected    = new Image(
      "http://icons.iconarchive.com/icons/aha-soft/desktop-buffet/128/Piece-of-cake-icon.png"
    );
    final ImageView    toggleImage = new ImageView();
    toggle.setGraphic(toggleImage);
    toggleImage.imageProperty().bind(Bindings
      .when(toggle.selectedProperty())
        .then(selected)
        .otherwise(unselected)
    );

    stage.setScene(new Scene(
      StackPaneBuilder.create()
        .children(toggle)
        .style("-fx-padding:10; -fx-background-color: cornsilk;")
        .build()
    ));
    stage.show();
  }
}

The code based approach has the advantage that you don't have to use css if you are unfamilar with it.

For best performance and ease of porting to unsigned applet and webstart sandboxes, bundle the images with your app and reference them by relative path urls rather than downloading them off the net.

Cannot create SSPI context

In my case it was a missing SPN, had to run these two commands:

setspn -a MSSQLSvc:SERVERNAME SERVERNAME setspn -a MSSQLSvc:SERVERNAME:1433 SERVERNAME

In other words in my case I had the FQDN in there already correctly but not just the NETBIOS name, after adding these it worked fine. Well initially it didn't but after waiting 2 minutes it did.

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

I just thought I should share how I actually solved the problem and why I think this is the right solution (provided you don't optimize for old browser).

Converting data to dataURL (data: ...)

var blob = new Blob(
              // I'm using page innerHTML as data
              // note that you can use the array
              // to concatenate many long strings EFFICIENTLY
              [document.body.innerHTML],
              // Mime type is important for data url
              {type : 'text/html'}
); 
// This FileReader works asynchronously, so it doesn't lag
// the web application
var a = new FileReader();
a.onload = function(e) {
     // Capture result here
     console.log(e.target.result);
};
a.readAsDataURL(blob);

Allowing user to save data

Apart from obvious solution - opening new window with your dataURL as URL you can do two other things.

1. Use fileSaver.js

File saver can create actual fileSave dialog with predefined filename. It can also fallback to normal dataURL approach.

2. Use (experimental) URL.createObjectURL

This is great for reusing base64 encoded data. It creates a short URL for your dataURL:

console.log(URL.createObjectURL(blob));
//Prints: blob:http://stackoverflow.com/7c18953f-f5f8-41d2-abf5-e9cbced9bc42

Don't forget to use the URL including the leading blob prefix. I used document.body again:

image description

You can use this short URL as AJAX target, <script> source or <a> href location. You're responsible for destroying the URL though:

URL.revokeObjectURL('blob:http://stackoverflow.com/7c18953f-f5f8-41d2-abf5-e9cbced9bc42')

css h1 - only as wide as the text

An easy fix for this is to float your H1 element left:

.centercol h1{
    background: #F2EFE9;
    border-left: 3px solid #C6C1B8;
    color: #006BB6;
    display: block;
    float: left;
    font-weight: normal;
    font-size: 18px;
    padding: 3px 3px 3px 6px;
}

I have put together a simple jsfiddle example that shows the effect of the "float: left" style on the width of your H1 element for anyone looking for a more generic answer:

http://jsfiddle.net/zmEBt/1/

read string from .resx file in C#

Once you add a resource (Name: ResourceName and Value: ResourceValue) to the solution/assembly, you could simply use "Properties.Resources.ResourceName" to get the required resource.

Add a common Legend for combined ggplots

I suggest using cowplot. From their R vignette:

# load cowplot
library(cowplot)

# down-sampled diamonds data set
dsamp <- diamonds[sample(nrow(diamonds), 1000), ]

# Make three plots.
# We set left and right margins to 0 to remove unnecessary spacing in the
# final plot arrangement.
p1 <- qplot(carat, price, data=dsamp, colour=clarity) +
   theme(plot.margin = unit(c(6,0,6,0), "pt"))
p2 <- qplot(depth, price, data=dsamp, colour=clarity) +
   theme(plot.margin = unit(c(6,0,6,0), "pt")) + ylab("")
p3 <- qplot(color, price, data=dsamp, colour=clarity) +
   theme(plot.margin = unit(c(6,0,6,0), "pt")) + ylab("")

# arrange the three plots in a single row
prow <- plot_grid( p1 + theme(legend.position="none"),
           p2 + theme(legend.position="none"),
           p3 + theme(legend.position="none"),
           align = 'vh',
           labels = c("A", "B", "C"),
           hjust = -1,
           nrow = 1
           )

# extract the legend from one of the plots
# (clearly the whole thing only makes sense if all plots
# have the same legend, so we can arbitrarily pick one.)
legend_b <- get_legend(p1 + theme(legend.position="bottom"))

# add the legend underneath the row we made earlier. Give it 10% of the height
# of one plot (via rel_heights).
p <- plot_grid( prow, legend_b, ncol = 1, rel_heights = c(1, .2))
p

combined plots with legend at bottom

How to loop through a plain JavaScript object with the objects as members?

I think it's worth pointing out that jQuery sorts this out nicely with $.each().

See: .each()

Example:

$('.foo').each(function() {
    console.log($(this));
});

$(this) being the single item inside the object. Swap $('.foo') to a variable if you don't want to use jQuery's selector engine.

How to remove pip package after deleting it manually

packages installed using pip can be uninstalled completely using

pip uninstall <package>

refrence link

pip uninstall is likely to fail if the package is installed using python setup.py install as they do not leave behind metadata to determine what files were installed.

packages still show up in pip list if their paths(.pth file) still exist in your site-packages or dist-packages folder. You'll need to remove them as well in case you're removing using rm -rf

jQuery - How to dynamically add a validation rule

As well as making sure that you have first called $("#myForm").validate();, make sure that your dynamic control has been added to the DOM before adding the validation rules.

What's the "Content-Length" field in HTTP header?

The Content-Length entity-header field indicates the size of the entity-body, in decimal number of OCTETs, sent to the recipient or, in the case of the HEAD method, the size of the entity-body that would have been sent had the request been a GET.

Content-Length = "Content-Length" ":" 1*DIGIT

An example is

Content-Length: 1024

Applications SHOULD use this field to indicate the transfer-length of the message-body.

In PHP you would use something like this.

header("Content-Length: ".filesize($filename));

In case of "Content-Type: application/x-www-form-urlencoded" the encoded data is sent to the processing agent designated so you can set the length or size of the data you are going to post.

Datetime in where clause

Use a convert function to get all entries for a particular day.

Select * from tblErrorLog where convert(date,errorDate,101) = '12/20/2008'

See CAST and CONVERT for more info

allowing only alphabets in text box using java script

You can use HTML5 pattern attribute to do this:

<form>
    <input type='text' pattern='[A-Za-z\\s]*'/>
</form>

If the user enters an input that conflicts with the pattern, it will show an error dialogue automatically.

When to use static keyword before global variables?

You should not define global variables in header files. You should define them in .c source file.

  • If global variable is to be visible within only one .c file, you should declare it static.

  • If global variable is to be used across multiple .c files, you should not declare it static. Instead you should declare it extern in header file included by all .c files that need it.

Example:

  • example.h

    extern int global_foo;
    
  • foo.c

    #include "example.h"
    
    int global_foo = 0;
    static int local_foo = 0;
    
    int foo_function()
    {
       /* sees: global_foo and local_foo
          cannot see: local_bar  */
       return 0;
    }
    
  • bar.c

    #include "example.h"
    
    static int local_bar = 0;
    static int local_foo = 0;
    
    int bar_function()
    {
        /* sees: global_foo, local_bar */
        /* sees also local_foo, but it's not the same local_foo as in foo.c
           it's another variable which happen to have the same name.
           this function cannot access local_foo defined in foo.c
        */
        return 0;
    }
    

How can I catch a ctrl-c event?

signal isn't the most reliable way as it differs in implementations. I would recommend using sigaction. Tom's code would now look like this :

#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

void my_handler(int s){
           printf("Caught signal %d\n",s);
           exit(1); 

}

int main(int argc,char** argv)
{

   struct sigaction sigIntHandler;

   sigIntHandler.sa_handler = my_handler;
   sigemptyset(&sigIntHandler.sa_mask);
   sigIntHandler.sa_flags = 0;

   sigaction(SIGINT, &sigIntHandler, NULL);

   pause();

   return 0;    
}

Remove file extension from a file name string

if you want to use String operation then you can use the function lastIndexOf( ) which Searches for the last occurrence of a character or substring. Java has numerous string functions.

How to load json into my angular.js ng-model?

Here's a simple example of how to load JSON data into an Angular model.

I have a JSON 'GET' web service which returns a list of Customer details, from an online copy of Microsoft's Northwind SQL Server database.

http://www.iNorthwind.com/Service1.svc/getAllCustomers

It returns some JSON data which looks like this:

{ 
    "GetAllCustomersResult" : 
        [
            {
              "CompanyName": "Alfreds Futterkiste",
              "CustomerID": "ALFKI"
            },
            {
              "CompanyName": "Ana Trujillo Emparedados y helados",
              "CustomerID": "ANATR"
            },
            {
              "CompanyName": "Antonio Moreno Taquería",
              "CustomerID": "ANTON"
            }
        ]
    }

..and I want to populate a drop down list with this data, to look like this...

Angular screenshot

I want the text of each item to come from the "CompanyName" field, and the ID to come from the "CustomerID" fields.

How would I do it ?

My Angular controller would look like this:

function MikesAngularController($scope, $http) {

    $scope.listOfCustomers = null;

    $http.get('http://www.iNorthwind.com/Service1.svc/getAllCustomers')
         .success(function (data) {
             $scope.listOfCustomers = data.GetAllCustomersResult;
         })
         .error(function (data, status, headers, config) {
             //  Do some error handling here
         });
}

... which fills a "listOfCustomers" variable with this set of JSON data.

Then, in my HTML page, I'd use this:

<div ng-controller='MikesAngularController'>
    <span>Please select a customer:</span>
    <select ng-model="selectedCustomer" ng-options="customer.CustomerID as customer.CompanyName for customer in listOfCustomers" style="width:350px;"></select>
</div>

And that's it. We can now see a list of our JSON data on a web page, ready to be used.

The key to this is in the "ng-options" tag:

customer.CustomerID as customer.CompanyName for customer in listOfCustomers

It's a strange syntax to get your head around !

When the user selects an item in this list, the "$scope.selectedCustomer" variable will be set to the ID (the CustomerID field) of that Customer record.

The full script for this example can be found here:

JSON data with Angular

Mike

linux script to kill java process

if there are multiple java processes and you wish to kill them with one command try the below command

kill -9 $(ps -ef | pgrep -f "java")

replace "java" with any process string identifier , to kill anything else.

possibly undefined macro: AC_MSG_ERROR

Using MacOS X

sudo port install pkgconfig

was the solution!

Database cluster and load balancing

From SQL Server point of view:

Clustering will give you an active - passive configuration. Meaning in a 2 node cluster, one of them will be the active (serving) and the other one will be passive (waiting to take over when the active node fails). It's a high availability from hardware point of view.

You can have an active-active cluster, but it will require multiple instances of SQL Server running on each node. (i.e. Instance 1 on Node A failing over to Instance 2 on Node B, and instance 1 on Node B failing over to instance 2 on Node A).

Load balancing (at least from SQL Server point of view) does not exists (at least in the same sense of web server load balancing). You can't balance load that way. However, you can split your application to run on some database on server 1 and also run on some database on server 2, etc. This is the primary mean of "load balancing" in SQL world.

TypeError: Cannot read property "0" from undefined

Check your array index to see if it's accessed out of bound.

Once I accessed categories[0]. Later I changed the array name from categories to category but forgot to change the access point--from categories[0] to category[0], thus I also get this error.

JavaScript does a poor debug message. In your case, I reckon probably the access gets out of bound.

Global variables in header file

Dont define varibale in header file , do declaration in header file(good practice ) .. in your case it is working because multiple weak symbols .. Read about weak and strong symbol ....link :http://csapp.cs.cmu.edu/public/ch7-preview.pdf

This type of code create problem while porting.

Django {% with %} tags within {% if %} {% else %} tags?

if you want to stay DRY, use an include.

{% if foo %}
  {% with a as b %}
    {% include "snipet.html" %}
  {% endwith %} 
{% else %}
  {% with bar as b %}
    {% include "snipet.html" %}
  {% endwith %} 
{% endif %}

or, even better would be to write a method on the model that encapsulates the core logic:

def Patient(models.Model):
    ....
    def get_legally_responsible_party(self):
       if self.age > 18:
          return self
       else:
          return self.parent

Then in the template:

{% with patient.get_legally_responsible_party as p %}
  Do html stuff
{% endwith %} 

Then in the future, if the logic for who is legally responsible changes you have a single place to change the logic -- far more DRY than having to change if statements in a dozen templates.

WPF: ItemsControl with scrollbar (ScrollViewer)

You have to modify the control template instead of ItemsPanelTemplate:

<ItemsControl >
    <ItemsControl.Template>
        <ControlTemplate>
            <ScrollViewer x:Name="ScrollViewer" Padding="{TemplateBinding Padding}">
                <ItemsPresenter />
            </ScrollViewer>
        </ControlTemplate>
    </ItemsControl.Template>
</ItemsControl>

Maybe, your code does not working because StackPanel has own scrolling functionality. Try to use StackPanel.CanVerticallyScroll property.

How do I loop through items in a list box and then remove those item?

You have to go through the collection from the last item to the first. this code is in vb

for i as integer= list.items.count-1 to 0 step -1
....
list.items.removeat(i)
next

Counting null and non-null values in a single query

Just to provide yet another alternative, Postgres 9.4+ allows applying a FILTER to aggregates:

SELECT
  COUNT(*) FILTER (WHERE a IS NULL) count_nulls,
  COUNT(*) FILTER (WHERE a IS NOT NULL) count_not_nulls
FROM us;

SQLFiddle: http://sqlfiddle.com/#!17/80a24/5

php refresh current page?

PHP refresh current page

With PHP code:

<?php
$secondsWait = 1;
header("Refresh:$secondsWait");
echo date('Y-m-d H:i:s');
?>

Note: Remember that header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from PHP.

if you send any output, you can use javascript:

<?php
echo date('Y-m-d H:i:s');
echo '<script type="text/javascript">location.reload(true);</script>';
?>

When this method receives a true value as argument, it will cause the page to always be reloaded from the server. If it is false or not specified, the browser may reload the page from its cache.

Or you can explicitly use "meta refresh" (with pure html):

<?php
$secondsWait = 1;
echo date('Y-m-d H:i:s');
echo '<meta http-equiv="refresh" content="'.$secondsWait.'">';
?>

Greetings and good code,

async await return Task

This is a Task that is returning a Task of type String (C# anonymous function or in other word a delegation is used 'Func')

    public static async Task<string> MyTask()
    {
        //C# anonymous AsyncTask
        return await Task.FromResult<string>(((Func<string>)(() =>
        {
            // your code here
            return  "string result here";

        }))());
    }

how to get the child node in div using javascript

var tds = document.getElementById("ctl00_ContentPlaceHolder1_Jobs_dlItems_ctl01_a").getElementsByTagName("td");
time = tds[0].firstChild.value;
address = tds[3].firstChild.value;

Mapping object to dictionary and vice versa

I'd highly recommend the Castle DictionaryAdapter, easily one of that project's best-kept secrets. You only need to define an interface with the properties you want, and in one line of code the adapter will generate an implementation, instantiate it, and synchronize its values with a dictionary you pass in. I use it to strongly-type my AppSettings in a web project:

var appSettings =
  new DictionaryAdapterFactory().GetAdapter<IAppSettings>(ConfigurationManager.AppSettings);

Note that I did not need to create a class that implements IAppSettings - the adapter does that on the fly. Also, although in this case I'm only reading, in theory if I were setting property values on appSettings, the adapter would keep the underlying dictionary in sync with those changes.

How to combine class and ID in CSS selector?

In your stylesheet:

div#content.myClass

Edit: These might help, too:

div#content.myClass.aSecondClass.aThirdClass /* Won't work in IE6, but valid */
div.firstClass.secondClass /* ditto */

and, per your example:

div#content.sectionA

Edit, 4 years later: Since this is super old and people keep finding it: don't use the tagNames in your selectors. #content.myClass is faster than div#content.myClass because the tagName adds a filtering step that you don't need. Use tagNames in selectors only where you must!

Form Submit Execute JavaScript Best Practice?

I know it's a little late for this. But I always thought that the best way to create event listeners is directly from JavaScript. Kind of like not applying inline CSS styles.

function validate(){
    //do stuff
}
function init(){
    document.getElementById('form').onsubmit = validate;
}
window.onload = init;

That way you don't have a bunch of event listeners throughout your HTML.

Transaction isolation levels relation with locks on table

I want to understand the lock each transaction isolation takes on the table

For example, you have 3 concurrent processes A, B and C. A starts a transaction, writes data and commit/rollback (depending on results). B just executes a SELECT statement to read data. C reads and updates data. All these process work on the same table T.

  • READ UNCOMMITTED - no lock on the table. You can read data in the table while writing on it. This means A writes data (uncommitted) and B can read this uncommitted data and use it (for any purpose). If A executes a rollback, B still has read the data and used it. This is the fastest but most insecure way to work with data since can lead to data holes in not physically related tables (yes, two tables can be logically but not physically related in real-world apps =\).
  • READ COMMITTED - lock on committed data. You can read the data that was only committed. This means A writes data and B can't read the data saved by A until A executes a commit. The problem here is that C can update data that was read and used on B and B client won't have the updated data.
  • REPEATABLE READ - lock on a block of SQL(which is selected by using select query). This means B reads the data under some condition i.e. WHERE aField > 10 AND aField < 20, A inserts data where aField value is between 10 and 20, then B reads the data again and get a different result.
  • SERIALIZABLE - lock on a full table(on which Select query is fired). This means, B reads the data and no other transaction can modify the data on the table. This is the most secure but slowest way to work with data. Also, since a simple read operation locks the table, this can lead to heavy problems on production: imagine that T table is an Invoice table, user X wants to know the invoices of the day and user Y wants to create a new invoice, so while X executes the read of the invoices, Y can't add a new invoice (and when it's about money, people get really mad, especially the bosses).

I want to understand where we define these isolation levels: only at JDBC/hibernate level or in DB also

Using JDBC, you define it using Connection#setTransactionIsolation.

Using Hibernate:

<property name="hibernate.connection.isolation">2</property>

Where

  • 1: READ UNCOMMITTED
  • 2: READ COMMITTED
  • 4: REPEATABLE READ
  • 8: SERIALIZABLE

Hibernate configuration is taken from here (sorry, it's in Spanish).

By the way, you can set the isolation level on RDBMS as well:

and on and on...

String escape into XML

Thanks to @sehe for the one-line escape:

var escaped = new System.Xml.Linq.XText(unescaped).ToString();

I add to it the one-line un-escape:

var unescapedAgain = System.Xml.XmlReader.Create(new StringReader("<r>" + escaped + "</r>")).ReadElementString();

How to use RANK() in SQL Server

Change:

RANK() OVER (PARTITION BY ContenderNum ORDER BY totals ASC) AS xRank

to:

RANK() OVER (ORDER BY totals DESC) AS xRank

Have a look at this example:

SQL Fiddle DEMO

You might also want to have a look at the difference between RANK (Transact-SQL) and DENSE_RANK (Transact-SQL):

RANK (Transact-SQL)

If two or more rows tie for a rank, each tied rows receives the same rank. For example, if the two top salespeople have the same SalesYTD value, they are both ranked one. The salesperson with the next highest SalesYTD is ranked number three, because there are two rows that are ranked higher. Therefore, the RANK function does not always return consecutive integers.

DENSE_RANK (Transact-SQL)

Returns the rank of rows within the partition of a result set, without any gaps in the ranking. The rank of a row is one plus the number of distinct ranks that come before the row in question.

Reflection generic get field value

I use the reflections in the toString() implementation of my preference class to see the class members and values (simple and quick debugging).

The simplified code I'm using:

@Override
public String toString() {
    StringBuilder sb = new StringBuilder();

    Class<?> thisClass = null;
    try {
        thisClass = Class.forName(this.getClass().getName());

        Field[] aClassFields = thisClass.getDeclaredFields();
        sb.append(this.getClass().getSimpleName() + " [ ");
        for(Field f : aClassFields){
            String fName = f.getName();
            sb.append("(" + f.getType() + ") " + fName + " = " + f.get(this) + ", ");
        }
        sb.append("]");
    } catch (Exception e) {
        e.printStackTrace();
    }

    return sb.toString();
}

I hope that it will help someone, because I also have searched.

How to use a keypress event in AngularJS?

you can use ng-keydown , ng-keyup , ng-press such as this .

to triger a function :

   <input type="text" ng-keypress="function()"/>

or if you have one condion such as when he press escape (27 is the key code for escape)

 <form ng-keydown=" event.which=== 27?cancelSplit():0">
....
</form>

Setting up foreign keys in phpMyAdmin?

Step 1: You have to add the line: default-storage-engine = InnoDB under the [mysqld] section of your mysql config file (my.cnf or my.ini depending on your OS) and restart the mysqld service. enter image description here

Step 2: Now when you create the table you will see the type of table is: InnoDB

enter image description here

Step 3: Create both Parent and Child table. Now open the Child table and select the column U like to have the Foreign Key: Select the Index Key from Action Label as shown below.

enter image description here

Step 4: Now open the Relation View in the same child table from bottom near the Print View as shown below.

enter image description here Step 5: Select the column U like to have the Foreign key as Select the Parent column from the drop down. dbName.TableName.ColumnName

Select appropriate Values for ON DELETE and ON UPDATE enter image description here

File path to resource in our war/WEB-INF folder?

Now with Java EE 7 you can find the resource more easily with

InputStream resource = getServletContext().getResourceAsStream("/WEB-INF/my.json");

https://docs.oracle.com/javaee/7/api/javax/servlet/GenericServlet.html#getServletContext--

How to disable text selection highlighting

With SASS (SCSS syntax)

You can do this with a mixin:

// Disable selection
@mixin disable-selection {
    -webkit-touch-callout: none; /* iOS Safari */
    -webkit-user-select: none;   /* Safari */
    -khtml-user-select: none;    /* Konqueror HTML */
    -moz-user-select: none;      /* Firefox */
    -ms-user-select: none;       /* Internet Explorer/Edge */
    user-select: none;           /* Non-prefixed version, currently supported by Chrome and Opera */
}

// No selectable element
.no-selectable {
    @include disable-selection;
}

In an HTML tag:

<div class="no-selectable">TRY TO HIGHLIGHT</div>

Try it in this CodePen.

If you are using an autoprefixer you can remove other prefixes.

Browser compatibility here.

How do I position a div relative to the mouse pointer using jQuery?

<script type="text/javascript" language="JavaScript">

  var cX = 0;
  var cY = 0;
  var rX = 0;
  var rY = 0;

  function UpdateCursorPosition(e) {
    cX = e.pageX;
    cY = e.pageY;
  }

  function UpdateCursorPositionDocAll(e) {
    cX = event.clientX;
    cY = event.clientY;
  }
  if (document.all) {
    document.onmousemove = UpdateCursorPositionDocAll;
  } else {
    document.onmousemove = UpdateCursorPosition;
  }

  function AssignPosition(d) {
    if (self.pageYOffset) {
      rX = self.pageXOffset;
      rY = self.pageYOffset;
    } else if (document.documentElement && document.documentElement.scrollTop) {
      rX = document.documentElement.scrollLeft;
      rY = document.documentElement.scrollTop;
    } else if (document.body) {
      rX = document.body.scrollLeft;
      rY = document.body.scrollTop;
    }
    if (document.all) {
      cX += rX;
      cY += rY;
    }
    d.style.left = (cX + 10) + "px";
    d.style.top = (cY + 10) + "px";
  }

  function HideContent(d) {
    if (d.length < 1) {
      return;
    }
    document.getElementById(d).style.display = "none";
  }

  function ShowContent(d) {
    if (d.length < 1) {
      return;
    }
    var dd = document.getElementById(d);
    AssignPosition(dd);
    dd.style.display = "block";
  }

  function ReverseContentDisplay(d) {
    if (d.length < 1) {
      return;
    }
    var dd = document.getElementById(d);
    AssignPosition(dd);
    if (dd.style.display == "none") {
      dd.style.display = "block";
    } else {
      dd.style.display = "none";
    }
  }
  //-->
</script>


<a onmouseover="ShowContent('uniquename3'); return true;" onmouseout="HideContent('uniquename3'); return true;" href="javascript:ShowContent('uniquename3')">
[show on mouseover, hide on mouseout]
</a>
<div id="uniquename3" style="display:none;
position:absolute;
border-style: solid;
background-color: white;
padding: 5px;">
  Content goes here.
</div>

How to programmatically set SelectedValue of Dropdownlist when it is bound to XmlDataSource

This seems to work for me.

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            DropDownList1.DataBind(); // get the data into the list you can set it
            DropDownList1.Items.FindByValue("SOMECREDITPROBLEMS").Selected = true;
        }
    }

Find closest previous element jQuery

I know this is old, but was hunting for the same thing and ended up coming up with another solution which is fairly concise andsimple. Here's my way of finding the next or previous element, taking into account traversal over elements that aren't of the type we're looking for:

var ClosestPrev = $( StartObject ).prevAll( '.selectorClass' ).first();
var ClosestNext = $( StartObject ).nextAll( '.selectorClass' ).first();

I'm not 100% sure of the order that the collection from the nextAll/prevAll functions return, but in my test case, it appears that the array is in the direction expected. Might be helpful if someone could clarify the internals of jquery for that for a strong guarantee of reliability.

How can I render inline JavaScript with Jade / Pug?

No use script tag only.

Solution with |:

script
  | if (10 == 10) {
  |   alert("working")
  | }

Or with a .:

script.
  if (10 == 10) {
    alert("working")
  }

Get Line Number of certain phrase in file Python

for n,line in enumerate(open("file")):
    if "pattern" in line: print n+1

How can I generate a tsconfig.json file?

I recommend to uninstall typescript first with the command:

npm uninstall -g typescript

then use the chocolatey package in order to run:

choco install typescript

in PowerShell.

How can I avoid ResultSet is closed exception in Java?

A ResultSetClosedException could be thrown for two reasons.

1.) You have opened another connection to the database without closing all other connections.

2.) Your ResultSet may be returning no values. So when you try to access data from the ResultSet java will throw a ResultSetClosedException.

Use ffmpeg to add text subtitles

ffmpeg -i infile.mp4 -i infile.srt -c copy -c:s mov_text outfile.mp4

-vf subtitles=infile.srt will not work with -c copy


The order of -c copy -c:s mov_text is important. You are telling FFmpeg:

  1. Video: copy, Audio: copy, Subtitle: copy
  2. Subtitle: mov_text

If you reverse them, you are telling FFmpeg:

  1. Subtitle: mov_text
  2. Video: copy, Audio: copy, Subtitle: copy

Alternatively you could just use -c:v copy -c:a copy -c:s mov_text in any order.

Kotlin Error : Could not find org.jetbrains.kotlin:kotlin-stdlib-jre7:1.0.7

After fixing the build.gradle version, It started working 4.0.0 to 3.5.0

Android- Error:Execution failed for task ':app:transformClassesWithDexForRelease'

i fixed it just this code.

local.properties

org.gradle.jvmargs=-XX\:MaxHeapSize\=512m -Xmx512m

and you should do this changing on gradle

defaultConfig {
    applicationId "yourProjectPackage"
    minSdkVersion 15
    versionCode 1
    versionName "1.0"
    targetSdkVersion 23

    multiDexEnabled true //important
}

How do I obtain a Query Execution Plan in SQL Server?

Explaining execution plan can be very detailed and takes up quite a reading time, but in summary if you use 'explain' before the query it should give you a lot of info including which parts were executed first and so. if you wanna read a bit more details about this, I compiled a small blog about this which points you as well to the right refs. https://medium.com/swlh/jetbrains-datagrip-explain-plan-ac406772c470

java howto ArrayList push, pop, shift, and unshift

Underscore-java library contains methods push(values), pop(), shift() and unshift(values).

Code example:

import com.github.underscore.U:

List<String> strings = Arrays.asList("one", "two", " three");
List<String> newStrings = U.push(strings, "four", "five");
// ["one", " two", "three", " four", "five"]
String newPopString = U.pop(strings).fst();
// " three"
String newShiftString = U.shift(strings).fst();
// "one"
List<String> newUnshiftStrings = U.unshift(strings, "four", "five");
// ["four", " five", "one", " two", "three"]

Insert some string into given string at given index in Python

line='Name Age Group Class Profession'
arr = line.split()
for i in range(3):
    arr.insert(2, arr[2])
print(' '.join(arr))

How to resolve symbolic links in a shell script

readlink -e [filepath]

seems to be exactly what you're asking for - it accepts an arbirary path, resolves all symlinks, and returns the "real" path - and it's "standard *nix" that likely all systems already have

Get jQuery version from inspecting the jQuery object

FYI, for the cases where your page is loading with other javascript libraries like mootools that are conflicting with the $ symbol, you can use jQuery instead.

For instance, jQuery.fn.jquery or jQuery().jquery would work just fine:

screen shot for checking jQuery version

What does #defining WIN32_LEAN_AND_MEAN exclude exactly?

According the to Windows Dev Center WIN32_LEAN_AND_MEAN excludes APIs such as Cryptography, DDE, RPC, Shell, and Windows Sockets.

How store a range from excel into a Range variable?

Declare your dim as a variant, and pull the data as you would from an array. i.e.

Dim y As Variant
y = Range("A1:B2")

Now your excel range is all 1 variable (array), y

To pull the data, call the array position in the range "A1:B2" or whatever you choose. e.g.:

Msgbox y(1, 1)

This will return the top left box in the "A1:B2" range.

How do I get Bin Path?

This is what I used to accomplish to this:

System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, System.AppDomain.CurrentDomain.RelativeSearchPath ?? "");

Best way to check if a drop down list contains a value?

If the function return Nothing, you can try this below

if (ddlCustomerNumber.Items.FindByText(
    GetCustomerNumberCookie().ToString()) != Nothing)
{
...
}

Cannot deserialize the current JSON array (e.g. [1,2,3]) into type

I ran into this exact same error message. I tried Aditi's example, and then I realized what the real issue was. (Because I had another apiEndpoint making a similar call that worked fine.) In this case The object in my list had not had an interface extracted from it yet. So because I apparently missed a step, when it went to do the bind to the

List<OfthisModelType>

It failed to deserialize.

If you see this issue, check to see if that could be the issue.

How to verify if $_GET exists?

Please try it:

if(isset($_GET['id']) && !empty($_GET['id'])){
   echo $_GET["id"];
 }

How do I select an element that has a certain class?

It should be this way:

h2.myClass looks for h2 with class myClass. But you actually want to apply style for h2 inside .myClass so you can use descendant selector .myClass h2.

h2 {
    color: red;
}

.myClass {
    color: green;
}

.myClass h2 {
    color: blue;
}

Demo

This ref will give you some basic idea about the selectors and have a look at descendant selectors

MatPlotLib: Multiple datasets on the same scatter plot

I don't know, it works fine for me. Exact commands:

import scipy, pylab
ax = pylab.subplot(111)
ax.scatter(scipy.randn(100), scipy.randn(100), c='b')
ax.scatter(scipy.randn(100), scipy.randn(100), c='r')
ax.figure.show()

python: unhashable type error

As Jim Garrison said in the comment, no obvious reason why you'd make a one-element list out of drug.upper() (which implies drug is a string).

But that's not your error, as your function medications_minimum3() doesn't even use the second argument (something you should fix).

TypeError: unhashable type: 'list' usually means that you are trying to use a list as a hash argument (like for accessing a dictionary). I'd look for the error in counter[row[11]]+=1 -- are you sure that row[11] is of the right type? Sounds to me it might be a list.

Multiple conditions in WHILE loop

Your condition is wrong. myChar != 'n' || myChar != 'N' will always be true.

Use myChar != 'n' && myChar != 'N' instead

setup android on eclipse but don't know SDK directory

You can search your hard drive for one of the programs that's installed with the SDK. For instance, if you search for aapt.exe or adb.exe, they will be in the platform-tools directory underneath the installation directory (which is what you're after).

In a Bash script, how can I exit the entire script if a certain condition occurs?

Use set -e

#!/bin/bash

set -e

/bin/command-that-fails
/bin/command-that-fails2

The script will terminate after the first line that fails (returns nonzero exit code). In this case, command-that-fails2 will not run.

If you were to check the return status of every single command, your script would look like this:

#!/bin/bash

# I'm assuming you're using make

cd /project-dir
make
if [[ $? -ne 0 ]] ; then
    exit 1
fi

cd /project-dir2
make
if [[ $? -ne 0 ]] ; then
    exit 1
fi

With set -e it would look like:

#!/bin/bash

set -e

cd /project-dir
make

cd /project-dir2
make

Any command that fails will cause the entire script to fail and return an exit status you can check with $?. If your script is very long or you're building a lot of stuff it's going to get pretty ugly if you add return status checks everywhere.

checking for typeof error in JS

You can use obj.constructor.name to check the "class" of an object https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/name#Function_names_in_classes

For Example

var error = new Error("ValidationError");
console.log(error.constructor.name);

The above line will log "Error" which is the class name of the object. This could be used with any classes in javascript, if the class is not using a property that goes by the name "name"

How do I find files that do not contain a given string pattern?

You will actually need:

find .  -not  -ipath '.*svn*' -exec  grep  -H -E -o -c  "foo"  {} \; | grep :0\$

MySQL - UPDATE query with LIMIT

In addition to the nested approach above, you can accomplish the application of theLIMIT using JOIN on the same table:

UPDATE `table_name`
INNER JOIN (SELECT `id` from `table_name` order by `id` limit 0,100) as t2 using (`id`)
SET `name` = 'test'

In my experience the mysql query optimizer is happier with this structure.

How do you dynamically allocate a matrix?

Here is the most clear & intuitive way i know to allocate a dynamic 2d array in C++. Templated in this example covers all cases.

template<typename T> T** matrixAllocate(int rows, int cols, T **M)
{
    M = new T*[rows];
    for (int i = 0; i < rows; i++){
        M[i] = new T[cols];
    }
    return M;
}

... 

int main()
{
    ...
    int** M1 = matrixAllocate<int>(rows, cols, M1);
    double** M2 = matrixAllocate(rows, cols, M2);
    ...
}

Insert current date/time using now() in a field using MySQL/PHP

Like Pekka said, it should work this way. I can't reproduce the problem with this self-contained example:

<?php
    $pdo = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'localonly', 'localonly');
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

    $pdo->exec('
        CREATE TEMPORARY TABLE soFoo (
            id int auto_increment,
            first int,
            last int,
            whenadded DATETIME,
            primary key(id)
        )
    ');
    $pdo->exec('INSERT INTO soFoo (first,last,whenadded) VALUES (0,1,Now())');
    $pdo->exec('INSERT INTO soFoo (first,last,whenadded) VALUES (0,2,Now())');
    $pdo->exec('INSERT INTO soFoo (first,last,whenadded) VALUES (0,3,Now())');

    foreach( $pdo->query('SELECT * FROM soFoo', PDO::FETCH_ASSOC) as $row ) {
        echo join(' | ', $row), "\n";
    }

Which (currently) prints

1 | 0 | 1 | 2012-03-23 16:00:18
2 | 0 | 2 | 2012-03-23 16:00:18
3 | 0 | 3 | 2012-03-23 16:00:18

And here's (almost) the same script using a TIMESTAMP field and DEFAULT CURRENT_TIMESTAMP:

<?php
    $pdo = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'localonly', 'localonly');
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

    $pdo->exec('
        CREATE TEMPORARY TABLE soFoo (
            id int auto_increment,
            first int,
            last int,
            whenadded TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            primary key(id)
        )
    ');
    $pdo->exec('INSERT INTO soFoo (first,last) VALUES (0,1)');
    $pdo->exec('INSERT INTO soFoo (first,last) VALUES (0,2)');
    sleep(1);
    $pdo->exec('INSERT INTO soFoo (first,last) VALUES (0,3)');

    foreach( $pdo->query('SELECT * FROM soFoo', PDO::FETCH_ASSOC) as $row ) {
        echo join(' | ', $row), "\n";
    }

Conveniently, the timestamp is converted to the same datetime string representation as in the first example - at least with my PHP/PDO/mysqlnd version.

Jquery-How to grey out the background while showing the loading icon over it

1) "container" is a class and not an ID 2) .container - set z-index and display: none in your CSS and not inline unless there is a really good reason to do so. Demo@fiddle

$("#button").click(function() {
    $(".container").css("opacity", 0.2);
   $("#loading-img").css({"display": "block"});
});

CSS:

#loading-img {
    background: url(http://web.bogdanteodoru.com/wp-content/uploads/2012/01/bouncy-css3-loading-animation.jpg) center center no-repeat;  /* different for testing purposes */
    display: none;
    height: 100px; /* for testing purposes */
    z-index: 12;
}

And a demo with animated image.

How to select specific form element in jQuery?

I prefer an id descendant selector of your #form2, like this:

$("#form2 #name").val("Hello World!");

http://api.jquery.com/descendant-selector/

How to select an item from a dropdown list using Selenium WebDriver with java?

Just wrap your WebElement into Select Object as shown below

Select dropdown = new Select(driver.findElement(By.id("identifier")));

Once this is done you can select the required value in 3 ways. Consider an HTML file like this

<html>
<body>
<select id = "designation">
<option value = "MD">MD</option>
<option value = "prog"> Programmer </option>
<option value = "CEO"> CEO </option>
</option>
</select>
<body>
</html>

Now to identify dropdown do

Select dropdown = new Select(driver.findElement(By.id("designation")));

To select its option say 'Programmer' you can do

dropdown.selectByVisibleText("Programmer ");

or

dropdown.selectByIndex(1);

or

dropdown.selectByValue("prog");

Happy Coding :)

Convert string with commas to array

Split (",") can convert Strings with commas into a String array, here is my code snippet.

    var input ='Hybrid App, Phone-Gap, Apache Cordova, HTML5, JavaScript, BootStrap, JQuery, CSS3, Android Wear API'
    var output = input.split(",");
    console.log(output);

["Hybrid App", " Phone-Gap", " Apache Cordova", " HTML5", " JavaScript", " BootStrap", " JQuery", " CSS3", " Android Wear API"]

How to import a bak file into SQL Server Express

I had the same error. What worked for me is when you go for the SMSS GUI option, look at General, Files in Options settings. After I did that (replace DB, set location) all went well.

Reverse the ordering of words in a string

By doing a rotation of the string you can reverse the order of the words without reversing the order of the letters.

As each word is rotated to the end of the string we reduce the amount of the string to be rotated by the length of the word. We then rotate any spaces to in front of the word we just placed at the end and shorten the rotating part of the string by 1 for each space. If the entire string is rotated with out seeing a space we are done.

Here is am implementation in C+. The l variable contains the length of the buf to rotate, and n counts the number of rotations made.

    #include <stdio.h>
    #include <string.h>
    
    int main(char *argv[], int argc)
    {
      char buf[20] = "My name is X Y Z";
      int l = strlen(buf);
      int n = 1;
    
      while (l >= n) {
        unsigned char c = buf[0];
        for (int i = 1; i < l; i++) {
          buf[i-1] = buf[i];
        }
        buf[l - 1] = c;
        if (buf[0] == ' ' || c == ' ') {
          l -= n;
          n = 1;
        } else {
          n++;
        }
      }
    
      printf("%s\n", buf);
    }

The rotation code was purposely left very simple.

Determine Pixel Length of String in Javascript/jQuery?

I don't believe you can do just a string, but if you put the string inside of a <span> with the correct attributes (size, font-weight, etc); you should then be able to use jQuery to get the width of the span.

<span id='string_span' style='font-weight: bold; font-size: 12'>Here is my string</span>
<script>
  $('#string_span').width();
</script>

Xcode error "Could not find Developer Disk Image"

Just my two cents for iOS 10 (under NDA, but for people that can use it legally...)

  • Copying full folder (as other people said) works
  • Symbolic link seems not.

This was tested using Xcode 7.3 (std from Store) AND iPhone 6Plus with 10.0 (14A5261v).

Is Ruby pass by reference or by value?

Ruby is pass-by-value in a strict sense, BUT the values are references.

This could be called "pass-reference-by-value". This article has the best explanation I have read: http://robertheaton.com/2014/07/22/is-ruby-pass-by-reference-or-pass-by-value/

Pass-reference-by-value could briefly be explained as follows:

A function receives a reference to (and will access) the same object in memory as used by the caller. However, it does not receive the box that the caller is storing this object in; as in pass-value-by-value, the function provides its own box and creates a new variable for itself.

The resulting behavior is actually a combination of the classical definitions of pass-by-reference and pass-by-value.

Jquery Hide table rows

this might work for you...

$('.trhideclass1').hide();

 

<tr class="trhideclass1">
  <td>Label</td>
  <td>InputFile</td>
</tr>

Create URL from a String

URL url = new URL(yourUrl, "/api/v1/status.xml");

According to the javadocs this constructor just appends whatever resource to the end of your domain, so you would want to create 2 urls:

URL domain = new URL("http://example.com");
URL url = new URL(domain + "/files/resource.xml");

Sources: http://docs.oracle.com/javase/6/docs/api/java/net/URL.html

Padding a table row

give the td padding

How can I print using JQuery

There is a jquery print area. I've been using it for some time now.

$(".printMe").click(function(){
   $("#outprint").printArea({ mode: 'popup', popClose: true });
});

Evaluate expression given as a string

You can use the parse() function to convert the characters into an expression. You need to specify that the input is text, because parse expects a file by default:

eval(parse(text="5+5"))

Does a "Find in project..." feature exist in Eclipse IDE?

Press Ctrl + H to bring up the search that includes options to search via project, directory, etc.

How to remove files that are listed in the .gitignore but still on the repository?

An easier way that works regardless of the OS is to do

git rm -r --cached .
git add .
git commit -m "Drop files from .gitignore"

You basically remove and re-add all files, but git add will ignore the ones in .gitignore.

Using the --cached option will keep files in your filesystem, so you won't be removing files from your disk.

Note: Some pointed out in the comments that you will lose the history of all your files. I tested this with git 2.27.0 on MacOS and it is not the case. If you want to check what is happening, check your git diff HEAD~1 before you push your commit.

Setting a div's height in HTML with CSS

I gave up on strictly CSS and used a little jquery:

var leftcol = $("#leftcolumn");
var rightcol = $("#rightcolumn");
var leftcol_height = leftcol.height();
var rightcol_height = rightcol.height();

if (leftcol_height > rightcol_height)
    rightcol.height(leftcol_height);
else
    leftcol.height(rightcol_height);

How to extract request http headers from a request using NodeJS connect

To see a list of HTTP request headers, you can use :

console.log(JSON.stringify(req.headers));

to return a list in JSON format.

{
"host":"localhost:8081",
"connection":"keep-alive",
"cache-control":"max-age=0",
"accept":"text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
"upgrade-insecure-requests":"1",
"user-agent":"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.107 Safari/537.36",
"accept-encoding":"gzip, deflate, sdch",
"accept-language":"en-US,en;q=0.8,et;q=0.6"
}

rename the columns name after cbind the data

It's easy just add the name which you want to use in quotes before adding vector

a_matrix <- cbind(b_matrix,'Name-Change'= c_vector)

HTML5 <video> element on Android

Here I include how a friend of mine solved the problem of displaying videos in HTML in Nexus One:

I never was able to make the video play inline. Actually many people on the internet mention explicitly that inline video play in HTML is supported since Honeycomb, and we were fighting with Froyo and Gingerbread... Also for smaller phones I think that playing full screen is very natural - otherwise not so much is visible. So the goal was to make the video open in full screen. However, the proposed solutions in this thread did not work for us - clicking on the element triggered nothing. Furthermore the video controls were shown, but no poster was displayed so the user experience was even weirder. So what he did was the following:

Expose native code to the HTML to be callable via javascript:

JavaScriptInterface jsInterface = new JavaScriptInterface(this);
webView.getSettings().setJavaScriptEnabled(true);
webView.addJavascriptInterface(jsInterface, "JSInterface");

The code itself, had a function that called native activity to play the video:

public class JavaScriptInterface {
    private Activity activity;

    public JavaScriptInterface(Activity activiy) {
        this.activity = activiy;
    }

    public void startVideo(String videoAddress){
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.parse(videoAddress), "video/3gpp"); // The Mime type can actually be determined from the file
        activity.startActivity(intent);
    }
}

Then in the HTML itself he kept on failing make the video tag work playing the video. Thus, finally he decided to overwrite the onclick event of the video, making it do the actual play. This almost worked for him - except for no poster was displayed. Here comes the most weird part - he kept on receiving ERROR/AndroidRuntime(7391): java.lang.RuntimeException: Null or empty value for header "Host" every time he set the poster attribute of the tag. Finally he found the issue, which was very weird - it turned out that he had kept the source subtag in the video tag, but never used it. And weird enough exactly this was causing the problem. Now see his definition of the video section:

<video width="320" height="240" controls="controls" poster='poster.gif'  onclick="playVideo('file:///sdcard/test.3gp');" >
   Your browser does not support the video tag.
</video>

Of course you need to also add the definition of the javascript function in the head of the page:

<script>
  function playVideo(video){
    window.JSInterface.startVideo(video);
  }
</script>

I realize this is not purely HTML solution, but is the best we were able to do for Nexus One type of phone. All credits for this solution go to Dimitar Zlatkov Dimitrov.

Global Events in Angular

I'm using a message service that wraps an rxjs Subject (TypeScript)

Plunker example: Message Service

import { Injectable } from '@angular/core';
import { Subject } from 'rxjs/Subject';
import { Subscription } from 'rxjs/Subscription';
import 'rxjs/add/operator/filter'
import 'rxjs/add/operator/map'

interface Message {
  type: string;
  payload: any;
}

type MessageCallback = (payload: any) => void;

@Injectable()
export class MessageService {
  private handler = new Subject<Message>();

  broadcast(type: string, payload: any) {
    this.handler.next({ type, payload });
  }

  subscribe(type: string, callback: MessageCallback): Subscription {
    return this.handler
      .filter(message => message.type === type)
      .map(message => message.payload)
      .subscribe(callback);
  }
}

Components can subscribe and broadcast events (sender):

import { Component, OnDestroy } from '@angular/core'
import { MessageService } from './message.service'
import { Subscription } from 'rxjs/Subscription'

@Component({
  selector: 'sender',
  template: ...
})
export class SenderComponent implements OnDestroy {
  private subscription: Subscription;
  private messages = [];
  private messageNum = 0;
  private name = 'sender'

  constructor(private messageService: MessageService) {
    this.subscription = messageService.subscribe(this.name, (payload) => {
      this.messages.push(payload);
    });
  }

  send() {
    let payload = {
      text: `Message ${++this.messageNum}`,
      respondEvent: this.name
    }
    this.messageService.broadcast('receiver', payload);
  }

  clear() {
    this.messages = [];
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}

(receiver)

import { Component, OnDestroy } from '@angular/core'
import { MessageService } from './message.service'
import { Subscription } from 'rxjs/Subscription'

@Component({
  selector: 'receiver',
  template: ...
})
export class ReceiverComponent implements OnDestroy {
  private subscription: Subscription;
  private messages = [];

  constructor(private messageService: MessageService) {
    this.subscription = messageService.subscribe('receiver', (payload) => {
      this.messages.push(payload);
    });
  }

  send(message: {text: string, respondEvent: string}) {
    this.messageService.broadcast(message.respondEvent, message.text);
  }

  clear() {
    this.messages = [];
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}

The subscribe method of MessageService returns an rxjs Subscription object, which can be unsubscribed from like so:

import { Subscription } from 'rxjs/Subscription';
...
export class SomeListener {
  subscription: Subscription;

  constructor(private messageService: MessageService) {
    this.subscription = messageService.subscribe('someMessage', (payload) => {
      console.log(payload);
      this.subscription.unsubscribe();
    });
  }
}

Also see this answer: https://stackoverflow.com/a/36782616/1861779

Plunker example: Message Service

How to specify the port an ASP.NET Core application is hosted on?

Alternatively, you can specify port by running app via command line.

Simply run command:

dotnet run --server.urls http://localhost:5001

Note: Where 5001 is the port you want to run on.

Center an element in Bootstrap 4 Navbar

use mx-auto will do the job

<ul class="navbar-nav mx-auto">

C/C++ maximum stack size of program

(Added 26 Sept. 2020)

On 24 Oct. 2009, as @pixelbeat first pointed out here, Bruno Haible empirically discovered the following default thread stack sizes for several systems. He said that in a multithreaded program, "the default thread stack size is:"

- glibc i386, x86_64    7.4 MB
- Tru64 5.1             5.2 MB
- Cygwin                1.8 MB
- Solaris 7..10           1 MB
- MacOS X 10.5          460 KB
- AIX 5                  98 KB
- OpenBSD 4.0            64 KB
- HP-UX 11               16 KB

Note that the above units are all in MB and KB (base 1000 numbers), NOT MiB and KiB (base 1024 numbers). I've proven this to myself by verifying the 7.4 MB case.

He also stated that:

32 KB is more than you can safely allocate on the stack in a multithreaded program

And he said:

And the default stack size for sigaltstack, SIGSTKSZ, is

  • only 16 KB on some platforms: IRIX, OSF/1, Haiku.
  • only 8 KB on some platforms: glibc, NetBSD, OpenBSD, HP-UX, Solaris.
  • only 4 KB on some platforms: AIX.

Bruno

He wrote the following simple Linux C program to empirically determine the above values. You can run it on your system today to quickly see what your maximum thread stack size is, or you can run it online on GDBOnline here: https://onlinegdb.com/rkO9JnaHD.

Explanation: It simply creates a single new thread, so as to check the thread stack size and NOT the program stack size, in case they differ, then it has that thread repeatedly allocate 128 bytes of memory on the stack (NOT the heap), using the Linux alloca() call, after which it writes a 0 to the first byte of this new memory block, and then it prints out how many total bytes it has allocated. It repeats this process, allocating 128 more bytes on the stack each time, until the program crashes with a Segmentation fault (core dumped) error. The last value printed is the estimated maximum thread stack size allowed for your system.

Important note: alloca() allocates on the stack: even though this looks like dynamic memory allocation onto the heap, similar to a malloc() call, alloca() does NOT dynamically allocate onto the heap. Rather, alloca() is a specialized Linux function to "pseudo-dynamically" (I'm not sure what I'd call this, so that's the term I chose) allocate directly onto the stack as though it was statically-allocated memory. Stack memory used and returned by alloca() is scoped at the function-level, and is therefore "automatically freed when the function that called alloca() returns to its caller." That's why its static scope isn't exited and memory allocated by alloca() is NOT freed each time a for loop iteration is completed and the end of the for loop scope is reached. See man 3 alloca for details. Here's the pertinent quote (emphasis added):

DESCRIPTION
The alloca() function allocates size bytes of space in the stack frame of the caller. This temporary space is automatically freed when the function that called alloca() returns to its caller.

RETURN VALUE
The alloca() function returns a pointer to the beginning of the allocated space. If the allocation causes stack overflow, program behavior is undefined.

Here is Bruno Haible's program from 24 Oct. 2009, copied directly from the GNU mailing list here:

Again, you can run it live online here.

// By Bruno Haible
// 24 Oct. 2009
// Source: https://lists.gnu.org/archive/html/bug-coreutils/2009-10/msg00262.html

// =============== Program for determining the default thread stack size =========

#include <alloca.h>
#include <pthread.h>
#include <stdio.h>
void* threadfunc (void*p) {
  int n = 0;
  for (;;) {
    printf("Allocated %d bytes\n", n);
    fflush(stdout);
    n += 128;
    *((volatile char *) alloca(128)) = 0;
  }
}

int main()
{
  pthread_t thread;
  pthread_create(&thread, NULL, threadfunc, NULL);
  for (;;) {}
}

When I run it on GDBOnline using the link above, I get the exact same results each time I run it, as both a C and a C++17 program. It takes about 10 seconds or so to run. Here are the last several lines of the output:

Allocated 7449856 bytes
Allocated 7449984 bytes
Allocated 7450112 bytes
Allocated 7450240 bytes
Allocated 7450368 bytes
Allocated 7450496 bytes
Allocated 7450624 bytes
Allocated 7450752 bytes
Allocated 7450880 bytes
Segmentation fault (core dumped)

So, the thread stack size is ~7.45 MB for this system, as Bruno mentioned above (7.4 MB).

I've made a few changes to the program, mostly just for clarity, but also for efficiency, and a bit for learning.

Summary of my changes:

  1. [learning] I passed in BYTES_TO_ALLOCATE_EACH_LOOP as an argument to the threadfunc() just for practice passing in and using generic void* arguments in C.

  2. [efficiency] I made the main thread sleep instead of wastefully spinning.

  3. [clarity] I added more-verbose variable names, such as BYTES_TO_ALLOCATE_EACH_LOOP and bytes_allocated.

  4. [clarity] I changed this:

     *((volatile char *) alloca(128)) = 0;
    

    to this:

     volatile uint8_t * byte_buff = 
             (volatile uint8_t *)alloca(BYTES_TO_ALLOCATE_EACH_LOOP);
     byte_buff[0] = 0;
    

Here is my modified test program, which does exactly the same thing as Bruno's, and even has the same results:

You can run it online here, or download it from my repo here. If you choose to run it locally from my repo, here's the build and run commands I used for testing:

  1. Build and run it as a C program:

     mkdir -p bin && \
     gcc -Wall -Werror -g3 -O3 -std=c11 -pthread -o bin/tmp \
     onlinegdb--empirically_determine_max_thread_stack_size_GS_version.c && \
     time bin/tmp
    
  2. Build and run it as a C++ program:

     mkdir -p bin && \
     g++ -Wall -Werror -g3 -O3 -std=c++17 -pthread -o bin/tmp \
     onlinegdb--empirically_determine_max_thread_stack_size_GS_version.c && \
     time bin/tmp
    

It takes < 0.5 seconds to run locally on a fast computer with a thread stack size of ~7.4 MB.

Here's the program:

// =============== Program for determining the default thread stack size =========

// Modified by Gabriel Staples, 26 Sept. 2020

// Originally by Bruno Haible
// 24 Oct. 2009
// Source: https://lists.gnu.org/archive/html/bug-coreutils/2009-10/msg00262.html

#include <alloca.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h> // sleep

/// Thread function to repeatedly allocate memory within a thread, printing
/// the total memory allocated each time, until the program crashes. The last
/// value printed before the crash indicates how big a thread's stack size is.
void* threadfunc(void* bytes_to_allocate_each_loop)
{
    const uint32_t BYTES_TO_ALLOCATE_EACH_LOOP =
            *(uint32_t*)bytes_to_allocate_each_loop;

    uint32_t bytes_allocated = 0;
    while (true)
    {
        printf("bytes_allocated = %u\n", bytes_allocated);
        fflush(stdout);
        // NB: it appears that you don't necessarily need `volatile` here,
        // but you DO definitely need to actually use (ex: write to) the
        // memory allocated by `alloca()`, as we do below, or else the
        // `alloca()` call does seem to get optimized out on some systems,
        // making this whole program just run infinitely forever without
        // ever hitting the expected segmentation fault.
        volatile uint8_t * byte_buff =
                (volatile uint8_t *)alloca(BYTES_TO_ALLOCATE_EACH_LOOP);
        byte_buff[0] = 0;
        bytes_allocated += BYTES_TO_ALLOCATE_EACH_LOOP;
    }
}

int main()
{
    const uint32_t BYTES_TO_ALLOCATE_EACH_LOOP = 128;

    pthread_t thread;
    pthread_create(&thread, NULL, threadfunc,
                   (void*)(&BYTES_TO_ALLOCATE_EACH_LOOP));
    while (true)
    {
        const unsigned int SLEEP_SEC = 10000;
        sleep(SLEEP_SEC);
    }

    return 0;
}

Sample output (same results as Bruno Haible's original program):

bytes_allocated = 7450240                                                                                                                                                        
bytes_allocated = 7450368                                                                                                                                                        
bytes_allocated = 7450496                                                                                                                                                        
bytes_allocated = 7450624                                                                                                                                                        
bytes_allocated = 7450752                                                                                                                                                        
bytes_allocated = 7450880                                                                                                                                                        
Segmentation fault (core dumped) 

IF/ELSE Stored Procedure

Are you missing the 'SET' statement when assigning to your variables in the IF .. ELSE block?

Create MSI or setup project with Visual Studio 2012

To create setup projects in Visual Studio 2012 with InstallShield Limited Edition, watch this video.

The InstallShield limited edition that cannot install services.

"ISLE is by far the worst installer option and the upgraded, read - paid for, version is cumbersome to use at best and impossible in most situations. InnoSetup, Nullsoft, Advanced, WiX, or just about any other installer is better. If you did a survey you would see that nobody is using ISLE. I don't know why you guys continue to associate with InstallShield. It damages your credibility. Any developer worth half his weight in salt knows ISLE is worthless and when you stand behind it we have to question Microsoft's judgment."

By Edward Miller (comments in Visual Studio Installer Projects Extension).

The WiX Toolset, which, while powerful is exceeding user-unfriendly and has a steep learning curve. There is even a downloadable template for installing Windows services (ref. VS2012: Installer for Windows services?).

For Visual Studio 2013, see blog post Creating installers with Visual Studio.

How can I hide the Adobe Reader toolbar when displaying a PDF in the .NET WebBrowser control?

It appears the default setting for Adobe Reader X is for the toolbars not to be shown by default unless they are explicitly turned on by the user. And even when I turn them back on during a session, they don't show up automatically next time. As such, I suspect you have a preference set contrary to the default.

The state you desire, with the top and left toolbars not shown, is called "Read Mode". If you right-click on the document itself, and then click "Page Display Preferences" in the context menu that is shown, you'll be presented with the Adobe Reader Preferences dialog. (This is the same dialog you can access by opening the Adobe Reader application, and selecting "Preferences" from the "Edit" menu.) In the list shown in the left-hand column of the Preferences dialog, select "Internet". Finally, on the right, ensure that you have the "Display in Read Mode by default" box checked:

   Adobe Reader Preferences dialog

You can also turn off the toolbars temporarily by clicking the button at the right of the top toolbar that depicts arrows pointing to opposing corners:

   Adobe Reader Read Mode toolbar button

Finally, if you have "Display in Read Mode by default" turned off, but want to instruct the page you're loading not to display the toolbars (i.e., override the user's current preferences), you can append the following to the URL:

#toolbar=0&navpanes=0

So, for example, the following code will disable both the top toolbar (called "toolbar") and the left-hand toolbar (called "navpane"). However, if the user knows the keyboard combination (F8, and perhaps other methods as well), they will still be able to turn them back on.

string url = @"http://www.domain.com/file.pdf#toolbar=0&navpanes=0";
this._WebBrowser.Navigate(url);

You can read more about the parameters that are available for customizing the way PDF files open here on Adobe's developer website.

ValueError: math domain error

You may also use math.log1p.

According to the official documentation :

math.log1p(x)

Return the natural logarithm of 1+x (base e). The result is calculated in a way which is accurate for x near zero.

You may convert back to the original value using math.expm1 which returns e raised to the power x, minus 1.

receiver type *** for instance message is a forward declaration

Check if you imported the header files of classes that are throwing this error.

How to select the first row of each group?

A nice way of doing this with the dataframe api is using the argmax logic like so

  val df = Seq(
    (0,"cat26",30.9), (0,"cat13",22.1), (0,"cat95",19.6), (0,"cat105",1.3),
    (1,"cat67",28.5), (1,"cat4",26.8), (1,"cat13",12.6), (1,"cat23",5.3),
    (2,"cat56",39.6), (2,"cat40",29.7), (2,"cat187",27.9), (2,"cat68",9.8),
    (3,"cat8",35.6)).toDF("Hour", "Category", "TotalValue")

  df.groupBy($"Hour")
    .agg(max(struct($"TotalValue", $"Category")).as("argmax"))
    .select($"Hour", $"argmax.*").show

 +----+----------+--------+
 |Hour|TotalValue|Category|
 +----+----------+--------+
 |   1|      28.5|   cat67|
 |   3|      35.6|    cat8|
 |   2|      39.6|   cat56|
 |   0|      30.9|   cat26|
 +----+----------+--------+

How to comment a block in Eclipse?

I have Eclipse IDE for Java Developers Version: Juno Service Release 2 and it is -

Every line prepended with //

ctrl + / for both comment and uncomment .

Why do I get java.lang.AbstractMethodError when trying to load a blob in the db?

I got the same problem and resolved it.

To resolve this problem, you should upgrade commons-dbcp library to latest version (1.4). It will work with latest JDBC drivers.

Concatenate a list of pandas dataframes together

If the dataframes DO NOT all have the same columns try the following:

df = pd.DataFrame.from_dict(map(dict,df_list))

How can I prevent the textarea from stretching beyond his parent DIV element? (google-chrome issue only)

To disable resizing completely:

textarea {
    resize: none;
}

To allow only vertical resizing:

textarea {
    resize: vertical;
}

To allow only horizontal resizing:

textarea {
    resize: horizontal;
}

Or you can limit size:

textarea {
    max-width: 100px; 
    max-height: 100px;
}

To limit size to parents width and/or height:

textarea {
    max-width: 100%; 
    max-height: 100%;
}

Can I change the color of Font Awesome's icon color?

For me the only thing that worked is inline css + overriding

<i class="fas fa-ellipsis-v fa-2x" style="color:red !important"></i>

Handler "ExtensionlessUrlHandler-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list

Try to re-register ASP.NET with aspnet_regiis -i. It worked for me.

A likely path for .NET 4 (from elevated command prompt):

c:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -i

http://forums.iis.net/p/1190643/2026401.aspx

How can I set a website image that will show as preview on Facebook?

If you're using Weebly, start by viewing the published site and right-clicking the image to Copy Image Address. Then in Weebly, go to Edit Site, Pages, click the page you wish to use, SEO Settings, under Header Code enter the code from Shef's answer:

<meta property="og:image" content="/uploads/..." />

just replacing /uploads/... with the copied image address. Click Publish to apply the change.

You can skip the part of Shef's answer about namespace, because that's already set by default in Weebly.

Angular 2 Sibling Component Communication

Behaviour subjects. I wrote a blog about that.

import { BehaviorSubject } from 'rxjs/BehaviorSubject';
private noId = new BehaviorSubject<number>(0); 
  defaultId = this.noId.asObservable();

newId(urlId) {
 this.noId.next(urlId); 
 }

In this example i am declaring a noid behavior subject of type number. Also it is an observable. And if "something happend" this will change with the new(){} function.

So, in the sibling's components, one will call the function, to make the change, and the other one will be affected by that change, or vice-versa.

For example, I get the id from the URL and update the noid from the behavior subject.

public getId () {
  const id = +this.route.snapshot.paramMap.get('id'); 
  return id; 
}

ngOnInit(): void { 
 const id = +this.getId ();
 this.taskService.newId(id) 
}

And from the other side, I can ask if that ID is "what ever i want" and make a choice after that, in my case if i want to delte a task, and that task is the current url, it have to redirect me to the home:

delete(task: Task): void { 
  //we save the id , cuz after the delete function, we  gonna lose it 
  const oldId = task.id; 
  this.taskService.deleteTask(task) 
      .subscribe(task => { //we call the defaultId function from task.service.
        this.taskService.defaultId //here we are subscribed to the urlId, which give us the id from the view task 
                 .subscribe(urlId => {
            this.urlId = urlId ;
                  if (oldId == urlId ) { 
                // Location.call('/home'); 
                this.router.navigate(['/home']); 
              } 
          }) 
    }) 
}

Write to text file without overwriting in Java

try this one

_x000D_
_x000D_
public void writeFile(String arg1,String arg2) {_x000D_
  try {_x000D_
   if (!dir.exists()) {_x000D_
_x000D_
    if (dir.mkdirs()) {_x000D_
_x000D_
     Toast.makeText(getBaseContext(), "Directory created",_x000D_
       Toast.LENGTH_SHORT).show();_x000D_
    } else {_x000D_
     Toast.makeText(getBaseContext(),_x000D_
       "Error writng file " + filename, Toast.LENGTH_LONG)_x000D_
       .show();_x000D_
    }_x000D_
   }_x000D_
_x000D_
   else {_x000D_
_x000D_
    File file = new File(dir, filename);_x000D_
    if (!file.exists()) {_x000D_
     file.createNewFile();_x000D_
    }_x000D_
    _x000D_
    FileWriter fileWritter = new FileWriter(file, true);_x000D_
    BufferedWriter bufferWritter = new BufferedWriter(fileWritter);_x000D_
    bufferWritter.write(arg1 + "\n");_x000D_
    bufferWritter.close();_x000D_
_x000D_
            } catch (Exception e) {_x000D_
   e.printStackTrace();_x000D_
   Toast.makeText(getBaseContext(),_x000D_
     "Error writng file " + e.toString(), Toast.LENGTH_LONG)_x000D_
     .show();_x000D_
  }_x000D_
_x000D_
 }
_x000D_
_x000D_
_x000D_

NodeJs : TypeError: require(...) is not a function

For me, this was an issue with cyclic dependencies.

IOW, module A required module B, and module B required module A.

So in module B, require('./A') is an empty object rather than a function.

How to deal with cyclic dependencies in Node.js

How do I convert a number to a letter in Java?

You can try like this:

private String getCharForNumber(int i) {
    CharSequence css = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    if (i > 25) {
        return null;
    }
    return css.charAt(i) + "";
}

Showing Thumbnail for link in WhatsApp || og:image meta-tag doesn't work

I documented the perfect detailed solution here - https://amprandom.blogspot.com/2016/12/blogger-whatsapp-rich-link-preview.html There are seven steps to be done to get the perfect preview.

  1. Title : Add Keyword rich title to your webpage with maximum of 65 characters.

  2. Meta Description : Describe your web page in a maximum of 155 characters.

  3. og:title : Maximum 35 characters.

  4. og:url : Full link to your webpage address.

  5. og:description : Maximum 65 characters.

  6. og:image : Image(JPG or PNG) of size less than 300KB and minimum dimension of 300 x 200 pixel is advised.

  7. favicon : A small icon of dimensions 32 x 32 pixels.

In the above page, you have the required specifications, the character limit and sample tags. Do upvote once you find it satisfactory.

Why does Node.js' fs.readFile() return a buffer instead of string?

This comes up high on Google, so I'd like to add some contextual information about the original question (emphasis mine):

Why does Node.js' fs.readFile() return a buffer instead of string?

Because files aren't always text

Even if you as the programmer know it: Node has no idea what's in the file you're trying to read. It could be a text file, but it could just as well be a ZIP archive or a JPG image — Node doesn't know.

Because reading text files is tricky

Even if Node knew it were to read a text file, it still would have no idea which character encoding is used (i.e. how the bytes in the file map to human-readable characters), because the character encoding itself is not stored in the file.

There are ways to guess the character encoding of text files with more or less confidence (that's what text editors do when opening a file), but you usually don't want your code to rely on guesses without your explicit instruction.

Buffers to the rescue!

So, because it does not and can not know all these details, Node just reads the file byte for byte, without assuming anything about its contents.

And that's what the returned buffer is: an unopinionated container for raw binary content. How this content should be interpreted is up to you as the developer.

How to post data to specific URL using WebClient in C#

I just found the solution and yea it was easier than I thought :)

so here is the solution:

string URI = "http://www.myurl.com/post.php";
string myParameters = "param1=value1&param2=value2&param3=value3";

using (WebClient wc = new WebClient())
{
    wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
    string HtmlResult = wc.UploadString(URI, myParameters);
}

it works like charm :)

How to find a Java Memory Leak

Well, there's always the low tech solution of adding logging of the size of your maps when you modify them, then search the logs for which maps are growing beyond a reasonable size.

Different font size of strings in the same TextView

Just in case you're wondering how you can set multiple different sizes in the same textview, but using an absolute size and not a relative one, you can achieve that using AbsoluteSizeSpan instead of a RelativeSizeSpan.

Just get the dimension in pixels of the desired text size

int textSize1 = getResources().getDimensionPixelSize(R.dimen.text_size_1);
int textSize2 = getResources().getDimensionPixelSize(R.dimen.text_size_2);

and then create a new AbsoluteSpan based on the text

String text1 = "Hi";
String text2 = "there";

SpannableString span1 = new SpannableString(text1);
span1.setSpan(new AbsoluteSizeSpan(textSize1), 0, text1.length(), SPAN_INCLUSIVE_INCLUSIVE);

SpannableString span2 = new SpannableString(text2);
span2.setSpan(new AbsoluteSizeSpan(textSize2), 0, text2.length(), SPAN_INCLUSIVE_INCLUSIVE);

// let's put both spans together with a separator and all
CharSequence finalText = TextUtils.concat(span1, " ", span2);

Skip to next iteration in loop vba

For i = 2 To 24
  Level = Cells(i, 4)
  Return = Cells(i, 5)

  If Return = 0 And Level = 0 Then GoTo NextIteration
  'Go to the next iteration
  Else
  End If
  ' This is how you make a line label in VBA - Do not use keyword or
  ' integer and end it in colon
  NextIteration:
Next

Fatal error: Call to undefined function: ldap_connect()

Open the XAMMP php.ini file (the default path is C:\xammp\php\php.ini) and change the code (;extension=ldap) to extension=php_ldap.dll and save. Restart XAMMP and save.

php.ini

; Notes for Windows environments :
;
; - Many DLL files are located in the extensions/ (PHP 4) or ext/ (PHP 5+)
;   extension folders as well as the separate PECL DLL download (PHP 5+).
;   Be sure to appropriately set the extension_dir directive.
;
extension=bz2
extension=curl
extension=fileinfo
extension=gd2
extension=gettext
;extension=gmp
;extension=intl
;extension=imap
;extension=interbase
extension=php_ldap.dll

Error: the entity type requires a primary key

Removed and added back in the table using Scaffold-DbContext and the error went away

C++ vector of char array

FFWD to 2019. Although this code worketh in 2011 too.

// g++ prog.cc -Wall -std=c++11
#include <iostream>
#include <vector>

 using namespace std;

 template<size_t N>
    inline 
      constexpr /* compile time */
      array<char,N> string_literal_to_array ( char const (&charrar)[N] )
 {
    return std::to_array( charrar) ;
 }

 template<size_t N>
    inline 
      /* run time */
      vector<char> string_literal_to_vector ( char const (&charrar)[N] )
 {
    return { charrar, charrar + N };
 }


int main()
{
   constexpr auto arr = string_literal_to_array("Compile Time");
   auto cv = string_literal_to_vector ("Run Time") ;
   return 42;
}

Advice: try optimizing the use of std::string. For char buffering std::array<char,N> is the fastest, std::vector<char> is faster.

https://wandbox.org/permlink/wcasstoY56MWbHqd

When should I use a trailing slash in my URL?

The trailing slash does not matter for your root domain or subdomain. Google sees the two as equivalent.

But trailing slashes do matter for everything else because Google sees the two versions (one with a trailing slash and one without) as being different URLs. Conventionally, a trailing slash (/) at the end of a URL meant that the URL was a folder or directory.

A URL without a trailing slash at the end used to mean that the URL was a file.

Read more

Google recommendation

Setting href attribute at runtime

Small performance test comparision for three solutions:

  1. $(".link").prop('href',"https://example.com")
  2. $(".link").attr('href',"https://example.com")
  3. document.querySelector(".link").href="https://example.com";

enter image description here

Here you can perform test by yourself https://jsperf.com/a-href-js-change


We can read href values in following ways

  1. let href = $(selector).prop('href');
  2. let href = $(selector).attr('href');
  3. let href = document.querySelector(".link").href;

enter image description here

Here you can perform test by yourself https://jsperf.com/a-href-js-read

I lose my data when the container exits

My suggestion is to manage docker, with docker compose. Is an easy to way to manage all the docker's containers for your project, you can map the versions and link different containers to work together.

The docs are very simple to understand, better than docker's docs.

Docker-Compose Docs

Best

php multidimensional array get values

For people who searched for php multidimensional array get values and actually want to solve problem comes from getting one column value from a 2 dimensinal array (like me!), here's a much elegant way than using foreach, which is array_column

For example, if I only want to get hotel_name from the below array, and form to another array:

$hotels = [
    [
        'hotel_name' => 'Hotel A',
        'info' => 'Hotel A Info',
    ],
    [
        'hotel_name' => 'Hotel B',
        'info' => 'Hotel B Info',
    ]
];

I can do this using array_column:

$hotel_name = array_column($hotels, 'hotel_name');

print_r($hotel_name); // Which will give me ['Hotel A', 'Hotel B']

For the actual answer for this question, it can also be beautified by array_column and call_user_func_array('array_merge', $twoDimensionalArray);

Let's make the data in PHP:

$hotels = [
    [
        'hotel_name' => 'Hotel A',
        'info' => 'Hotel A Info',
        'rooms' => [
            [
                'room_name' => 'Luxury Room',
                'bed' => 2,
                'boards' => [
                    'board_id' => 1,
                    'price' => 200
                ]
            ],
            [
                'room_name' => 'Non Luxy Room',
                'bed' => 4,
                'boards' => [
                    'board_id' => 2,
                    'price' => 150
                ]
            ],
        ]
    ],
    [
        'hotel_name' => 'Hotel B',
        'info' => 'Hotel B Info',
        'rooms' => [
            [
                'room_name' => 'Luxury Room',
                'bed' => 2,
                'boards' => [
                    'board_id' => 3,
                    'price' => 900
                ]
            ],
            [
                'room_name' => 'Non Luxy Room',
                'bed' => 4,
                'boards' => [
                    'board_id' => 4,
                    'price' => 300
                ]
            ],
        ]
    ]
];

And here's the calculation:

$rooms = array_column($hotels, 'rooms');
$rooms = call_user_func_array('array_merge', $rooms);
$boards = array_column($rooms, 'boards');

foreach($boards as $board){
    $board_id = $board['board_id'];
    $price = $board['price'];
    echo "Board ID is: ".$board_id." and price is: ".$price . "<br/>";
}

Which will give you the following result:

Board ID is: 1 and price is: 200
Board ID is: 2 and price is: 150
Board ID is: 3 and price is: 900
Board ID is: 4 and price is: 300