Programs & Examples On #Flartoolkit

No shadow by default on Toolbar?

i added

<android.support.v7.widget.Toolbar
...
android:translationZ="5dp"/>

in toolbar description and it works for me. Using 5.0+

TensorFlow: "Attempting to use uninitialized value" in variable initialization

I want to give my resolution, it work when i replace the line [session = tf.Session()] with [sess = tf.InteractiveSession()]. Hope this will be useful to others.

Typescript react - Could not find a declaration file for module ''react-materialize'. 'path/to/module-name.js' implicitly has an any type

All you need to do is run the below script. Then, remove/re-install the module that you want to use.

npm install --save @types/react-redux

ld.exe: cannot open output file ... : Permission denied

I got this error when using the Atom editor and mingw (through a package called gpp-compiler) for C++. Closing the open console window fixed my issue.

Set auto height and width in CSS/HTML for different screen sizes

Using bootstrap with a little bit of customization, the following seems to work for me:

I need 3 partitions in my container and I tried this:

CSS:

.row.content {height: 100%; width:100%; position: fixed; }
.sidenav {
  padding-top: 20px;
  border: 1px solid #cecece;
  height: 100%;
}
.midnav {
  padding: 0px;
}

HTML:

  <div class="container-fluid text-center"> 
    <div class="row content">
    <div class="col-md-2 sidenav text-left">Some content 1</div>
    <div class="col-md-9 midnav text-left">Some content 2</div>
    <div class="col-md-1 sidenav text-center">Some content 3</div>
    </div>
  </div>

Java: Retrieving an element from a HashSet

It sounds like you're essentially trying to use the hash code as a key in a map (which is what HashSets do behind the scenes). You could just do it explicitly, by declaring HashMap<Integer, MyHashObject>.

There is no get for HashSets because typically the object you would supply to the get method as a parameter is the same object you would get back.

Formatting code in Notepad++

If all you need is alignment, try the plugin called Code Alignment.

You can get it from the built-in plugin manager in Notepad++.

Table scroll with HTML and CSS

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  .outer {_x000D_
    overflow-y: auto;_x000D_
    height: 300px;_x000D_
  }_x000D_
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  .outer {_x000D_
    width: 100%;_x000D_
    -layout: fixed;_x000D_
  }_x000D_
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  .outer th {_x000D_
    text-align: left;_x000D_
    top: 0;_x000D_
    position: sticky;_x000D_
    background-color: white;_x000D_
  }
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<!DOCTYPE html>_x000D_
<html lang="en">_x000D_
<head>_x000D_
    <meta charset="UTF-8">_x000D_
    <meta name="viewport" content="width=device-width, initial-scale=1.0">_x000D_
    <meta http-equiv="X-UA-Compatible" content="ie=edge">_x000D_
    <title>MYCRUD</title>_x000D_
    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.0/css/all.css" integrity="sha384-lZN37f5QGtY3VHgisS14W3ExzMWZxybE1SJSEsQp9S+oqd12jhcu+A56Ebc1zFSJ" crossorigin="anonymous">_x000D_
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">_x000D_
</head>_x000D_
<body>_x000D_
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<div class="container-fluid col-md-11">_x000D_
  <div class="row">_x000D_
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    <div class="col-lg-12">_x000D_
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   _x000D_
        <div class="card-body">_x000D_
          <div class="outer">_x000D_
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            <table class="table table-hover bg-light">_x000D_
              <thead>_x000D_
                <tr>_x000D_
                  <th scope="col">ID</th>_x000D_
                  <th scope="col">Marca</th>_x000D_
                  <th scope="col">Editar</th>_x000D_
                  <th scope="col">Eliminar</th>_x000D_
                </tr>_x000D_
              </thead>_x000D_
              <tbody>_x000D_
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                _x000D_
                  <tr>_x000D_
                    <td>4</td>_x000D_
                    <td>Toyota</td>_x000D_
                    <td> <a class="btn btn-success" href="#">_x000D_
                        <i class="fa fa-edit"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                    <td> <a class="btn btn-danger" href="#">_x000D_
                        <i class="fa fa-trash"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                  </tr>_x000D_
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                                  <tr>_x000D_
                    <td>3</td>_x000D_
                    <td>Honda </td>_x000D_
                    <td> <a class="btn btn-success" href="#">_x000D_
                        <i class="fa fa-edit"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                    <td> <a class="btn btn-danger" href="#">_x000D_
                        <i class="fa fa-trash"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                  </tr>_x000D_
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                                  <tr>_x000D_
                    <td>5</td>_x000D_
                    <td>Myo</td>_x000D_
                    <td> <a class="btn btn-success" href="#">_x000D_
                        <i class="fa fa-edit"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                    <td> <a class="btn btn-danger" href="#">_x000D_
                        <i class="fa fa-trash"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                  </tr>_x000D_
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                                  <tr>_x000D_
                    <td>6</td>_x000D_
                    <td>Acer</td>_x000D_
                    <td> <a class="btn btn-success" href="#">_x000D_
                        <i class="fa fa-edit"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                    <td> <a class="btn btn-danger" href="#">_x000D_
                        <i class="fa fa-trash"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                  </tr>_x000D_
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                                  <tr>_x000D_
                    <td>7</td>_x000D_
                    <td>HP</td>_x000D_
                    <td> <a class="btn btn-success" href="#">_x000D_
                        <i class="fa fa-edit"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                    <td> <a class="btn btn-danger" href="#">_x000D_
                        <i class="fa fa-trash"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                  </tr>_x000D_
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                                  <tr>_x000D_
                    <td>8</td>_x000D_
                    <td>DELL</td>_x000D_
                    <td> <a class="btn btn-success" href="#">_x000D_
                        <i class="fa fa-edit"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                    <td> <a class="btn btn-danger" href="#">_x000D_
                        <i class="fa fa-trash"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                  </tr>_x000D_
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                                  <tr>_x000D_
                    <td>9</td>_x000D_
                    <td>LOGITECH</td>_x000D_
                    <td> <a class="btn btn-success" href="#">_x000D_
                        <i class="fa fa-edit"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                    <td> <a class="btn btn-danger" href="#">_x000D_
                        <i class="fa fa-trash"></i>_x000D_
                      </a>_x000D_
                    </td>_x000D_
                  </tr>_x000D_
_x000D_
                              </tbody>_x000D_
            </table>_x000D_
          </div>_x000D_
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        </div>_x000D_
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     _x000D_
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    </div>_x000D_
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  </div>_x000D_
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</div>_x000D_
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</body>_x000D_
</html>
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jquery ajax get responsetext from http url

This is super old, but hopefully this helps somebody. I'm sending responses with different error codes back and this is the only solution I've found that works in

$.ajax({
    data: {
        "data": "mydata"
    },
    type: "POST",
    url: "myurl"
}).done(function(data){
    alert(data);
}).fail(function(data){
    alert(data.responseText)
});

Since JQuery deprecated the success and error functions, it's you need to use done and fail, and access the data with data.responseText when in fail, and just with data when in done. This is similar to @Marco Pavan 's answer, but you don't need any JQuery plugins or anything to use it.

How can I convert a comma-separated string to an array?

A good solution for that:

let obj = ['A','B','C']

obj.map((c) => { return c. }).join(', ')

Symfony - generate url with parameter in controller

It's pretty simple :

public function myAction()
{
    $url = $this->generateUrl('blog_show', array('slug' => 'my-blog-post'));
}

Inside an action, $this->generateUrl is an alias that will use the router to get the wanted route, also you could do this that is the same :

$this->get('router')->generate('blog_show', array('slug' => 'my-blog-post'));

How to mount the android img file under linux?

I have found that Furius ISO mount works best for me. I am using a Debian based distro Knoppix. I use this to Open system.img files all the time.

Furius ISO mount: https://packages.debian.org/sid/otherosfs/furiusisomount

"When I want to mount userdata.img by mount -o loop userdata.img /mnt/userdata (the same as system.img), it tells me mount: you must specify the filesystem type so I try the mount -t ext2 -o loop userdata.img /mnt/userdata, it said mount: wrong fs type, bad option, bad superblock on...

So, how to get the file from the inside of userdata.img?" To load .img files you have to select loop and load the .img Select loop

Next you select mount Select mount

Furius ISO mount handles all the other options loading the .img file to your /home/dir.

how to always round up to the next integer

This will also work:

c = (count - 1) / 10 + 1;

Polymorphism vs Overriding vs Overloading

Although, Polymorphism is already explained in great details in this post but I would like put more emphasis on why part of it.

Why Polymorphism is so important in any OOP language.

Let’s try to build a simple application for a TV with and without Inheritance/Polymorphism. Post each version of the application, we do a small retrospective.

Supposing, you are a software engineer at a TV company and you are asked to write software for Volume, Brightness and Colour controllers to increase and decrease their values on user command.

You start with writing classes for each of these features by adding

  1. set:- To set a value of a controller.(Supposing this has controller specific code)
  2. get:- To get a value of a controller.(Supposing this has controller specific code)
  3. adjust:- To validate the input and setting a controller.(Generic validations.. independent of controllers)
  4. user input mapping with controllers :- To get user input and invoking controllers accordingly.

Application Version 1

import java.util.Scanner;    
class VolumeControllerV1 {
    private int value;
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of VolumeController \t"+this.value);
        this.value = value;
        System.out.println("New value of VolumeController \t"+this.value);
    }
    void adjust(int value)  {
        int temp = this.get();
        if(((value > 0) && (temp >= 100)) || ((value < 0) && (temp <= 0)))    {
            System.out.println("Can not adjust any further");
            return;
        }
        this.set(temp + value);
    }
}
class  BrightnessControllerV1 {
    private int value;
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of BrightnessController \t"+this.value);
        this.value = value;
        System.out.println("New value of BrightnessController \t"+this.value);
    }
    void adjust(int value)  {
        int temp = this.get();
        if(((value > 0) && (temp >= 100)) || ((value < 0) && (temp <= 0)))    {
            System.out.println("Can not adjust any further");
            return;
        }
        this.set(temp + value);
    }
}
class ColourControllerV1    {
    private int value;
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of ColourController \t"+this.value);
        this.value = value;
        System.out.println("New value of ColourController \t"+this.value);
    }
    void adjust(int value)  {
        int temp = this.get();
        if(((value > 0) && (temp >= 100)) || ((value < 0) && (temp <= 0)))    {
            System.out.println("Can not adjust any further");
            return;
        }
        this.set(temp + value);
    }
}

/*
 *       There can be n number of controllers
 * */
public class TvApplicationV1 {
    public static void main(String[] args)  {
        VolumeControllerV1 volumeControllerV1 = new VolumeControllerV1();
        BrightnessControllerV1 brightnessControllerV1 = new BrightnessControllerV1();
        ColourControllerV1 colourControllerV1 = new ColourControllerV1();


        OUTER: while(true) {
            Scanner sc=new Scanner(System.in);
            System.out.println(" Enter your option \n Press 1 to increase volume \n Press 2 to decrease volume");
            System.out.println(" Press 3 to increase brightness \n Press 4 to decrease brightness");
            System.out.println(" Press 5 to increase color \n Press 6 to decrease color");
            System.out.println("Press any other Button to shutdown");
            int button = sc.nextInt();
            switch (button) {
                case  1:    {
                    volumeControllerV1.adjust(5);
                    break;
                }
                case 2: {
                    volumeControllerV1.adjust(-5);
                    break;
                }
                case  3:    {
                    brightnessControllerV1.adjust(5);
                    break;
                }
                case 4: {
                    brightnessControllerV1.adjust(-5);
                    break;
                }
                case  5:    {
                    colourControllerV1.adjust(5);
                    break;
                }
                case 6: {
                colourControllerV1.adjust(-5);
                break;
            }
            default:
                System.out.println("Shutting down...........");
                break OUTER;
        }

    }
    }
}

Now you have our first version of working application ready to be deployed. Time to analyze the work done so far.

Issues in TV Application Version 1

  1. Adjust(int value) code is duplicate in all three classes. You would like to minimize the code duplicity. (But you did not think of common code and moving it to some super class to avoid duplicate code)

You decide to live with that as long as your application works as expected.

After sometimes, your Boss comes back to you and asks you to add reset functionality to the existing application. Reset would set all 3 three controller to their respective default values.

You start writing a new class (ResetFunctionV2) for the new functionality and map the user input mapping code for this new feature.

Application Version 2

import java.util.Scanner;
class VolumeControllerV2    {

    private int defaultValue = 25;
    private int value;

    int getDefaultValue() {
        return defaultValue;
    }
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of VolumeController \t"+this.value);
        this.value = value;
        System.out.println("New value of VolumeController \t"+this.value);
    }
    void adjust(int value)  {
        int temp = this.get();
        if(((value > 0) && (temp >= 100)) || ((value < 0) && (temp <= 0)))    {
            System.out.println("Can not adjust any further");
            return;
        }
        this.set(temp + value);
    }
}
class  BrightnessControllerV2   {

    private int defaultValue = 50;
    private int value;
    int get()    {
        return value;
    }
    int getDefaultValue() {
        return defaultValue;
    }
    void set(int value) {
        System.out.println("Old value of BrightnessController \t"+this.value);
        this.value = value;
        System.out.println("New value of BrightnessController \t"+this.value);
    }
    void adjust(int value)  {
        int temp = this.get();
        if(((value > 0) && (temp >= 100)) || ((value < 0) && (temp <= 0)))    {
            System.out.println("Can not adjust any further");
            return;
        }
        this.set(temp + value);
    }
}
class ColourControllerV2    {

    private int defaultValue = 40;
    private int value;
    int get()    {
        return value;
    }
    int getDefaultValue() {
        return defaultValue;
    }
    void set(int value) {
        System.out.println("Old value of ColourController \t"+this.value);
        this.value = value;
        System.out.println("New value of ColourController \t"+this.value);
    }
    void adjust(int value)  {
        int temp = this.get();
        if(((value > 0) && (temp >= 100)) || ((value < 0) && (temp <= 0)))    {
            System.out.println("Can not adjust any further");
            return;
        }
        this.set(temp + value);
    }
}

class ResetFunctionV2 {

    private VolumeControllerV2 volumeControllerV2 ;
    private BrightnessControllerV2 brightnessControllerV2;
    private ColourControllerV2 colourControllerV2;

    ResetFunctionV2(VolumeControllerV2 volumeControllerV2, BrightnessControllerV2 brightnessControllerV2, ColourControllerV2 colourControllerV2)  {
        this.volumeControllerV2 = volumeControllerV2;
        this.brightnessControllerV2 = brightnessControllerV2;
        this.colourControllerV2 = colourControllerV2;
    }
    void onReset()    {
        volumeControllerV2.set(volumeControllerV2.getDefaultValue());
        brightnessControllerV2.set(brightnessControllerV2.getDefaultValue());
        colourControllerV2.set(colourControllerV2.getDefaultValue());
    }
}
/*
 *       so on
 *       There can be n number of controllers
 *
 * */
public class TvApplicationV2 {
    public static void main(String[] args)  {
        VolumeControllerV2 volumeControllerV2 = new VolumeControllerV2();
        BrightnessControllerV2 brightnessControllerV2 = new BrightnessControllerV2();
        ColourControllerV2 colourControllerV2 = new ColourControllerV2();

        ResetFunctionV2 resetFunctionV2 = new ResetFunctionV2(volumeControllerV2, brightnessControllerV2, colourControllerV2);

        OUTER: while(true) {
            Scanner sc=new Scanner(System.in);
            System.out.println(" Enter your option \n Press 1 to increase volume \n Press 2 to decrease volume");
            System.out.println(" Press 3 to increase brightness \n Press 4 to decrease brightness");
            System.out.println(" Press 5 to increase color \n Press 6 to decrease color");
            System.out.println(" Press 7 to reset TV \n Press any other Button to shutdown");
            int button = sc.nextInt();
            switch (button) {
                case  1:    {
                    volumeControllerV2.adjust(5);
                    break;
                }
                case 2: {
                    volumeControllerV2.adjust(-5);
                    break;
                }
                case  3:    {
                    brightnessControllerV2.adjust(5);
                    break;
                }
                case 4: {
                    brightnessControllerV2.adjust(-5);
                    break;
                }
                case  5:    {
                    colourControllerV2.adjust(5);
                    break;
                }
                case 6: {
                    colourControllerV2.adjust(-5);
                    break;
                }
                case 7: {
                    resetFunctionV2.onReset();
                    break;
                }
                default:
                    System.out.println("Shutting down...........");
                    break OUTER;
            }

        }
    }
}

So you have your application ready with Reset feature. But, now you start realizing that

Issues in TV Application Version 2

  1. If a new controller is introduced to the product, you have to change Reset feature code.
  2. If the count of the controller grows very high, you would have issue in holding the references of the controllers.
  3. Reset feature code is tightly coupled with all the controllers Class’s code(to get and set default values).
  4. Reset feature class (ResetFunctionV2) can access other method of the Controller class’s (adjust) which is undesirable.

At the same time, You hear from you Boss that you might have to add a feature wherein each of controllers, on start-up, needs to check for the latest version of driver from company’s hosted driver repository via internet.

Now you start thinking that this new feature to be added resembles with Reset feature and Issues of Application (V2) will be multiplied if you don’t re-factor your application.

You start thinking of using inheritance so that you can take advantage from polymorphic ability of JAVA and you add a new abstract class (ControllerV3) to

  1. Declare the signature of get and set method.
  2. Contain adjust method implementation which was earlier replicated among all the controllers.
  3. Declare setDefault method so that reset feature can be easily implemented leveraging Polymorphism.

With these improvements, you have version 3 of your TV application ready with you.

Application Version 3

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

abstract class ControllerV3 {
    abstract void set(int value);
    abstract int get();
    void adjust(int value)  {
        int temp = this.get();
        if(((value > 0) && (temp >= 100)) || ((value < 0) && (temp <= 0)))    {
            System.out.println("Can not adjust any further");
            return;
        }
        this.set(temp + value);
    }
    abstract void setDefault();
}
class VolumeControllerV3 extends ControllerV3   {

    private int defaultValue = 25;
    private int value;

    public void setDefault() {
        set(defaultValue);
    }
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of VolumeController \t"+this.value);
        this.value = value;
        System.out.println("New value of VolumeController \t"+this.value);
    }
}
class  BrightnessControllerV3  extends ControllerV3   {

    private int defaultValue = 50;
    private int value;

    public void setDefault() {
        set(defaultValue);
    }
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of BrightnessController \t"+this.value);
        this.value = value;
        System.out.println("New value of BrightnessController \t"+this.value);
    }
}
class ColourControllerV3 extends ControllerV3   {

    private int defaultValue = 40;
    private int value;

    public void setDefault() {
        set(defaultValue);
    }
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of ColourController \t"+this.value);
        this.value = value;
        System.out.println("New value of ColourController \t"+this.value);
    }
}

class ResetFunctionV3 {

    private List<ControllerV3> controllers = null;

    ResetFunctionV3(List<ControllerV3> controllers)  {
        this.controllers = controllers;
    }
    void onReset()    {
        for (ControllerV3 controllerV3 :this.controllers)  {
            controllerV3.setDefault();
        }
    }
}
/*
 *       so on
 *       There can be n number of controllers
 *
 * */
public class TvApplicationV3 {
    public static void main(String[] args)  {
        VolumeControllerV3 volumeControllerV3 = new VolumeControllerV3();
        BrightnessControllerV3 brightnessControllerV3 = new BrightnessControllerV3();
        ColourControllerV3 colourControllerV3 = new ColourControllerV3();

        List<ControllerV3> controllerV3s = new ArrayList<>();
        controllerV3s.add(volumeControllerV3);
        controllerV3s.add(brightnessControllerV3);
        controllerV3s.add(colourControllerV3);

        ResetFunctionV3 resetFunctionV3 = new ResetFunctionV3(controllerV3s);

        OUTER: while(true) {
            Scanner sc=new Scanner(System.in);
            System.out.println(" Enter your option \n Press 1 to increase volume \n Press 2 to decrease volume");
            System.out.println(" Press 3 to increase brightness \n Press 4 to decrease brightness");
            System.out.println(" Press 5 to increase color \n Press 6 to decrease color");
            System.out.println(" Press 7 to reset TV \n Press any other Button to shutdown");
            int button = sc.nextInt();
            switch (button) {
                case  1:    {
                    volumeControllerV3.adjust(5);
                    break;
                }
                case 2: {
                    volumeControllerV3.adjust(-5);
                    break;
                }
                case  3:    {
                    brightnessControllerV3.adjust(5);
                    break;
                }
                case 4: {
                    brightnessControllerV3.adjust(-5);
                    break;
                }
                case  5:    {
                    colourControllerV3.adjust(5);
                    break;
                }
                case 6: {
                    colourControllerV3.adjust(-5);
                    break;
                }
                case 7: {
                    resetFunctionV3.onReset();
                    break;
                }
                default:
                    System.out.println("Shutting down...........");
                    break OUTER;
            }

        }
    }
}

Although most of the Issue listed in issue list of V2 were addressed except

Issues in TV Application Version 3

  1. Reset feature class (ResetFunctionV3) can access other method of the Controller class’s (adjust) which is undesirable.

Again, you think of solving this problem, as now you have another feature (driver update at startup) to implement as well. If you don’t fix it, it will get replicated to new features as well.

So you divide the contract defined in abstract class and write 2 interfaces for

  1. Reset feature.
  2. Driver Update.

And have your 1st concrete class implement them as below

Application Version 4

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

interface OnReset {
    void setDefault();
}
interface OnStart {
    void checkForDriverUpdate();
}
abstract class ControllerV4 implements OnReset,OnStart {
    abstract void set(int value);
    abstract int get();
    void adjust(int value)  {
        int temp = this.get();
        if(((value > 0) && (temp >= 100)) || ((value < 0) && (temp <= 0)))    {
            System.out.println("Can not adjust any further");
            return;
        }
        this.set(temp + value);
    }
}

class VolumeControllerV4 extends ControllerV4 {

    private int defaultValue = 25;
    private int value;
    @Override
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of VolumeController \t"+this.value);
        this.value = value;
        System.out.println("New value of VolumeController \t"+this.value);
    }
    @Override
    public void setDefault() {
        set(defaultValue);
    }

    @Override
    public void checkForDriverUpdate()    {
        System.out.println("Checking driver update for VolumeController .... Done");
    }
}
class  BrightnessControllerV4 extends ControllerV4 {

    private int defaultValue = 50;
    private int value;
    @Override
    int get()    {
        return value;
    }
    @Override
    void set(int value) {
        System.out.println("Old value of BrightnessController \t"+this.value);
        this.value = value;
        System.out.println("New value of BrightnessController \t"+this.value);
    }

    @Override
    public void setDefault() {
        set(defaultValue);
    }

    @Override
    public void checkForDriverUpdate()    {
        System.out.println("Checking driver update for BrightnessController .... Done");
    }
}
class ColourControllerV4 extends ControllerV4 {

    private int defaultValue = 40;
    private int value;
    @Override
    int get()    {
        return value;
    }
    void set(int value) {
        System.out.println("Old value of ColourController \t"+this.value);
        this.value = value;
        System.out.println("New value of ColourController \t"+this.value);
    }
    @Override
    public void setDefault() {
        set(defaultValue);
    }

    @Override
    public void checkForDriverUpdate()    {
        System.out.println("Checking driver update for ColourController .... Done");
    }
}
class ResetFunctionV4 {

    private List<OnReset> controllers = null;

    ResetFunctionV4(List<OnReset> controllers)  {
        this.controllers = controllers;
    }
    void onReset()    {
        for (OnReset onreset :this.controllers)  {
            onreset.setDefault();
        }
    }
}
class InitializeDeviceV4 {

    private List<OnStart> controllers = null;

    InitializeDeviceV4(List<OnStart> controllers)  {
        this.controllers = controllers;
    }
    void initialize()    {
        for (OnStart onStart :this.controllers)  {
            onStart.checkForDriverUpdate();
        }
    }
}
/*
*       so on
*       There can be n number of controllers
*
* */
public class TvApplicationV4 {
    public static void main(String[] args)  {
        VolumeControllerV4 volumeControllerV4 = new VolumeControllerV4();
        BrightnessControllerV4 brightnessControllerV4 = new BrightnessControllerV4();
        ColourControllerV4 colourControllerV4 = new ColourControllerV4();
        List<ControllerV4> controllerV4s = new ArrayList<>();
        controllerV4s.add(brightnessControllerV4);
        controllerV4s.add(volumeControllerV4);
        controllerV4s.add(colourControllerV4);

        List<OnStart> controllersToInitialize = new ArrayList<>();
        controllersToInitialize.addAll(controllerV4s);
        InitializeDeviceV4 initializeDeviceV4 = new InitializeDeviceV4(controllersToInitialize);
        initializeDeviceV4.initialize();

        List<OnReset> controllersToReset = new ArrayList<>();
        controllersToReset.addAll(controllerV4s);
        ResetFunctionV4 resetFunctionV4 = new ResetFunctionV4(controllersToReset);

        OUTER: while(true) {
            Scanner sc=new Scanner(System.in);
            System.out.println(" Enter your option \n Press 1 to increase volume \n Press 2 to decrease volume");
            System.out.println(" Press 3 to increase brightness \n Press 4 to decrease brightness");
            System.out.println(" Press 5 to increase color \n Press 6 to decrease color");
            System.out.println(" Press 7 to reset TV \n Press any other Button to shutdown");
            int button = sc.nextInt();
            switch (button) {
                case  1:    {
                    volumeControllerV4.adjust(5);
                    break;
                }
                case 2: {
                    volumeControllerV4.adjust(-5);
                    break;
                }
                case  3:    {
                    brightnessControllerV4.adjust(5);
                    break;
                }
                case 4: {
                    brightnessControllerV4.adjust(-5);
                    break;
                }
                case  5:    {
                    colourControllerV4.adjust(5);
                    break;
                }
                case 6: {
                    colourControllerV4.adjust(-5);
                    break;
                }
                case 7: {
                    resetFunctionV4.onReset();
                    break;
                }
                default:
                    System.out.println("Shutting down...........");
                    break OUTER;
            }

        }
    }
}

Now all of the issue faced by you got addressed and you realized that with the use of Inheritance and Polymorphism you could

  1. Keep various part of application loosely coupled.( Reset or Driver Update feature components don’t need to be made aware of actual controller classes(Volume, Brightness and Colour), any class implementing OnReset or OnStart will be acceptable to Reset or Driver Update feature components respectively).
  2. Application enhancement becomes easier.(New addition of controller wont impact reset or driver update feature component, and it is now really easy for you to add new ones)
  3. Keep layer of abstraction.(Now Reset feature can see only setDefault method of controllers and Reset feature can see only checkForDriverUpdate method of controllers)

Hope, this helps :-)

Why I am getting Cannot pass parameter 2 by reference error when I am using bindParam with a constant value?

For those who still have problems (Cannot pass parameter 2 by reference), define a variable with null value, not just pass null to PDO:

bindValue(':param', $n = null, PDO::PARAM_INT);

Hope this helps.

How to cancel/abort jQuery AJAX request?

Why should you abort the request?

If each request takes more than five seconds, what will happen?

You shouldn't abort the request if the parameter passing with the request is not changing. eg:- the request is for retrieving the notification data. In such situations, The nice approach is that set a new request only after completing the previous Ajax request.

$(document).ready(

    var fn = function(){

        $.ajax({
            url: 'ajax/progress.ftl',
            success: function(data) {
                //do something
            },

            complete: function(){setTimeout(fn, 500);}
        });
    };

     var interval = setTimeout(fn, 500);

);

What is PECS (Producer Extends Consumer Super)?

The principles behind this in computer science is called

  • Covariance: ? extends MyClass,
  • Contravariance: ? super MyClass and
  • Invariance/non-variance: MyClass

The picture below should explain the concept. Picture courtesy: Andrey Tyukin

Covariance vs Contravariance

Find size of object instance in bytes in c#

From Pavel and jnm2:

private int DumpApproximateObjectSize(object toWeight)
{
   return Marshal.ReadInt32(toWeight.GetType().TypeHandle.Value, 4);
}

On a side note be careful because it only work with contiguous memory objects

Declaring a variable and setting its value from a SELECT query in Oracle

One Additional point:

When you are converting from tsql to plsql you have to worry about no_data_found exception

DECLARE
   v_var NUMBER;
BEGIN
   SELECT clmn INTO v_var FROM tbl;
Exception when no_data_found then v_var := null; --what ever handle the exception.
END;

In tsql if no data found then the variable will be null but no exception

Getting list of parameter names inside python function

locals() returns a dictionary with local names:

def func(a,b,c):
    print(locals().keys())

prints the list of parameters. If you use other local variables those will be included in this list. But you could make a copy at the beginning of your function.

How to initialize std::vector from C-style array?

The quick generic answer:

std::vector<double> vec(carray,carray+carray_size); 

or question specific:

std::vector<double> w_(w,w+len); 

based on above: Don't forget that you can treat pointers as iterators

How to check if a service is running via batch file and start it, if it is not running?

To check a service's state, use sc query <SERVICE_NAME>. For if blocks in batch files, check the documentation.

The following code will check the status of the service MyServiceName and start it if it is not running (the if block will be executed if the service is not running):

for /F "tokens=3 delims=: " %%H in ('sc query "MyServiceName" ^| findstr "        STATE"') do (
  if /I "%%H" NEQ "RUNNING" (
   REM Put your code you want to execute here
   REM For example, the following line
   net start "MyServiceName"
  )
)

Explanation of what it does:

  1. Queries the properties of the service.
  2. Looks for the line containing the text "STATE"
  3. Tokenizes that line, and pulls out the 3rd token, which is the one containing the state of the service.
  4. Tests the resulting state against the string "RUNNING"

As for your second question, the argument you will want to pass to net start is the service name, not the display name.

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

This maybe is a bit ugly hack, but it works pretty well when you don't need more than the default float precision (about 11 decimals).

The round_to function uses the format method from the built-in str class to round up the float to a string that represents the float with the number of decimals needed, and then applies the eval built-in function to the rounded float string to get back to the float numeric type.

The is_close function just applies a simple conditional to the rounded up float.

def round_to(float_num, prec):
    return eval("'{:." + str(int(prec)) + "f}'.format(" + str(float_num) + ")")

def is_close(float_a, float_b, prec):
    if round_to(float_a, prec) == round_to(float_b, prec):
        return True
    return False

>>>a = 10.0
10.0
>>>b = 10.0001
10.0001
>>>print is_close(a, b, prec=3)
True
>>>print is_close(a, b, prec=4)
False

Update:

As suggested by @stepehjfox, a cleaner way to build a rount_to function avoiding "eval" is using nested formatting:

def round_to(float_num, prec):
    return '{:.{precision}f}'.format(float_num, precision=prec)

Following the same idea, the code can be even simpler using the great new f-strings (Python 3.6+):

def round_to(float_num, prec):
    return f'{float_num:.{prec}f}'

So, we could even wrap it up all in one simple and clean 'is_close' function:

def is_close(a, b, prec):
    return f'{a:.{prec}f}' == f'{b:.{prec}f}'

Java, how to compare Strings with String Arrays

Right now you seem to be saying 'does this array of strings equal this string', which of course it never would.

Perhaps you should think about iterating through your array of strings with a loop, and checking each to see if they are equals() with the inputted string?

...or do I misunderstand your question?

How to send 500 Internal Server Error error from a PHP script

Your code should look like:

<?php
if ( that_happened ) {
    header("HTTP/1.0 500 Internal Server Error");
    die();
}

if ( something_else_happened ) {
    header("HTTP/1.0 500 Internal Server Error");
    die();
}

// Your function should return FALSE if something goes wrong
if ( !update_database() ) {
    header("HTTP/1.0 500 Internal Server Error");
    die();
}

// the script can also fail on the above line
// e.g. a mysql error occurred


header('HTTP/1.1 200 OK');
?>

I assume you stop execution if something goes wrong.

Limit Decimal Places in Android EditText

I achieved this with the help of TextWatcher by the following way

final EditText et = (EditText) findViewById(R.id.EditText1);
int count = -1;
et.addTextChangedListener(new TextWatcher() {
    public void onTextChanged(CharSequence arg0, int arg1, int arg2,int arg3) {             

    }
    public void beforeTextChanged(CharSequence arg0, int arg1,int arg2, int arg3) {             

    }

    public void afterTextChanged(Editable arg0) {
        if (arg0.length() > 0) {
            String str = et.getText().toString();
            et.setOnKeyListener(new OnKeyListener() {
                public boolean onKey(View v, int keyCode, KeyEvent event) {
                    if (keyCode == KeyEvent.KEYCODE_DEL) {
                        count--;
                        InputFilter[] fArray = new InputFilter[1];
                        fArray[0] = new InputFilter.LengthFilter(100);
                        et.setFilters(fArray);
                        //change the edittext's maximum length to 100. 
                        //If we didn't change this the edittext's maximum length will
                        //be number of digits we previously entered.
                    }
                    return false;
                }
            });
            char t = str.charAt(arg0.length() - 1);
            if (t == '.') {
                count = 0;
            }
            if (count >= 0) {
                if (count == 2) {                        
                    InputFilter[] fArray = new InputFilter[1];
                    fArray[0] = new InputFilter.LengthFilter(arg0.length());
                    et.setFilters(fArray);
                    //prevent the edittext from accessing digits 
                    //by setting maximum length as total number of digits we typed till now.
                }
                count++;
            }
        }
    }
});

This solution will not allow the user to enter more than two digit after decimal point. Also you can enter any number of digits before decimal point. See this blog http://v4all123.blogspot.com/2013/05/set-limit-for-fraction-in-decimal.html to set filter for multiple EditText. I hope this will help. Thank you.

How to Cast Objects in PHP

You do not need casting. Everything is dynamic.

I have a class Discount.
I have several classes that extends this class:
ProductDiscount
StoreDiscount
ShippingDiscount
...

Somewhere in the code I have:

$pd = new ProductDiscount();
$pd->setDiscount(5, ProductDiscount::PRODUCT_DISCOUNT_PERCENT);
$pd->setProductId(1);

$this->discounts[] = $pd;

.....

$sd = new StoreDiscount();
$sd->setDiscount(5, StoreDiscount::STORE_DISCOUNT_PERCENT);
$sd->setStoreId(1);

$this->discounts[] = $sd;

And somewhere I have:

foreach ($this->discounts as $discount){

    if ($discount->getDiscountType()==Discount::DISCOUNT_TYPE_PRODUCT){

        $productDiscount = $discount; // you do not need casting.
        $amount = $productDiscount->getDiscountAmount($this->getItemTotalPrice());
        ...
    }

}// foreach

Where getDiscountAmount is ProductDiscount specific function, and getDiscountType is Discount specific function.

HTML5 best practices; section/header/aside/article elements

The main mistake: You have "divitis" in the whole document.
Why this?

<header>
    <div id="logo"></div>
    <div id="language"></div>
</header>

Instead of:

<header role="banner">
    <!-- Not the best -->
    <h1 id="logo"></h1> <!-- or <figure> and <figcaption>, or <h1> and <p>... -->
    <h2 id="language"></h2>

    <!-- Better, if the IDs have not semantic sense -->
    <h1></h1>
    <h2></h2>
</header>

To stylize this header, use CSS hierarchy: body > section > header > h1, body > section > header > h2

More, ...line 63: why header wraps h2?? If you do not include any more element inside header, just use a single h2.
Keep in mind, your structure is not to stylize document, but construct a document self-explained.

Apply this to the rest of document; Good luck ;)

How to add DOM element script to head section?

Here is a safe and reusable function for adding script to head section if its not already exist there.

see working example here: Example

<!DOCTYPE html>
<html>
  <head>
    <base href="/"/>
    <style>
    </style>
  </head>
  <body>
    <input type="button" id="" style='width:250px;height:50px;font-size:1.5em;' value="Add Script" onClick="addScript('myscript')"/>
    <script>
      function addScript(filename)
      {
        // house-keeping: if script is allready exist do nothing
        if(document.getElementsByTagName('head')[0].innerHTML.toString().includes(filename + ".js"))
        {
          alert("script is allready exist in head tag!")
        }
        else
        {
          // add the script
          loadScript('/',filename + ".js");
        }
      }
      function loadScript(baseurl,filename)
      {
        var node = document.createElement('script');
        node.src = baseurl + filename;
        document.getElementsByTagName('head')[0].appendChild(node);
        alert("script added");
      }
    </script>
  </body>
</html>

How to leave space in HTML

You can use &nbsp;, aka a Non-Breaking Space.

It is essentially a standard space, the primary difference being that a browser should not break (or wrap) a line of text at the point that this &nbsp; occupies.

Is there a SELECT ... INTO OUTFILE equivalent in SQL Server Management Studio?

In SQL Management Studio you can:

  1. Right click on the result set grid, select 'Save Result As...' and save in.

  2. On a tool bar toggle 'Result to Text' button. This will prompt for file name on each query run.

If you need to automate it, use bcp tool.

How to type a new line character in SQL Server Management Studio

You're talking about right-clicking on a table and selecting "Edit Top 50 Rows", right?

I tried [Ctl][Enter] and [Alt][Enter], but neither of those works.

Even when I insert data with CR/LF (using a standard INSERT statement), it shows up here in a single line with a rectangle representing the control codes.

ASP.NET MVC 404 Error Handling

The response from Marco is the BEST solution. I needed to control my error handling, and I mean really CONTROL it. Of course, I have extended the solution a little and created a full error management system that manages everything. I have also read about this solution in other blogs and it seems very acceptable by most of the advanced developers.

Here is the final code that I am using:

protected void Application_EndRequest()
    {
        if (Context.Response.StatusCode == 404)
        {
            var exception = Server.GetLastError();
            var httpException = exception as HttpException;
            Response.Clear();
            Server.ClearError();
            var routeData = new RouteData();
            routeData.Values["controller"] = "ErrorManager";
            routeData.Values["action"] = "Fire404Error";
            routeData.Values["exception"] = exception;
            Response.StatusCode = 500;

            if (httpException != null)
            {
                Response.StatusCode = httpException.GetHttpCode();
                switch (Response.StatusCode)
                {
                    case 404:
                        routeData.Values["action"] = "Fire404Error";
                        break;
                }
            }
            // Avoid IIS7 getting in the middle
            Response.TrySkipIisCustomErrors = true;
            IController errormanagerController = new ErrorManagerController();
            HttpContextWrapper wrapper = new HttpContextWrapper(Context);
            var rc = new RequestContext(wrapper, routeData);
            errormanagerController.Execute(rc);
        }
    }

and inside my ErrorManagerController :

        public void Fire404Error(HttpException exception)
    {
        //you can place any other error handling code here
        throw new PageNotFoundException("page or resource");
    }

Now, in my Action, I am throwing a Custom Exception that I have created. And my Controller is inheriting from a custom Controller Based class that I have created. The Custom Base Controller was created to override error handling. Here is my custom Base Controller class:

public class MyBasePageController : Controller
{
    protected override void OnException(ExceptionContext filterContext)
    {
        filterContext.GetType();
        filterContext.ExceptionHandled = true;
        this.View("ErrorManager", filterContext).ExecuteResult(this.ControllerContext);
        base.OnException(filterContext);
    }
}

The "ErrorManager" in the above code is just a view that is using a Model based on ExceptionContext

My solution works perfectly and I am able to handle ANY error on my website and display different messages based on ANY exception type.

How can I check whether an array is null / empty?

I tested as below. Hope it helps.

Integer[] integers1 = new Integer[10];
        System.out.println(integers1.length); //it has length 10 but it is empty. It is not null array
        for (Integer integer : integers1) {
            System.out.println(integer); //prints all 0s
        }

//But if I manually add 0 to any index, now even though array has all 0s elements
//still it is not empty
//        integers1[2] = 0;
        for (Integer integer : integers1) {
            System.out.println(integer); //Still it prints all 0s but it is not empty
            //but that manually added 0 is different
        }

//Even we manually add 0, still we need to treat it as null. This is semantic logic.

        Integer[] integers2 = new Integer[20];
        integers2 = null; //array is nullified
//        integers2[3] = null; //If I had int[] -- because it is priitive -- then I can't write this line. 
        if (integers2 == null) {
            System.out.println("null Array");
        }   

Launch an event when checking a checkbox in Angular2

If you add double paranthesis to the ngModel reference you get a two-way binding to your model property. That property can then be read and used in the event handler. In my view that is the most clean approach.

<input type="checkbox" [(ngModel)]="myModel.property" (ngModelChange)="processChange()" />

git replacing LF with CRLF

In vim open the file (e.g.: :e YOURFILEENTER), then

:set noendofline binary
:wq

Can you display HTML5 <video> as a full screen background?

Just a comment on this - I've used HTML5 video for a full-screen background and it works a treat - but make sure to use either Height:100% and width:auto or the other way around - to ensure you keep aspect ratio.

As for Ipads -you can (apparently) do this, by having a hidden and then forcing the click event to fire, and having the function of the click event kick off the Load/Play().

P.s - this shouldn't require any plugins and can be done with minimal JS - If you're targeting any mobile device (I would assume you might be..) staying away from any such framework is the way forward.

CSS align one item right with flexbox

For a terse, pure flexbox option, group the left-aligned items and the right-aligned items:

<div class="wrap">
  <div>
    <span>One</span>
    <span>Two</span>
  </div>
  <div>Three</div>
</div>

and use space-between:

.wrap {
  display: flex;
  background: #ccc;
  justify-content: space-between;
}

This way you can group multiple items to the right(or just one).

https://jsfiddle.net/c9mkewwv/3/

Get user location by IP address

Use http://ipinfo.io , You need to pay them if you make more than 1000 requests per day.

The code below requires the Json.NET package.

public static string GetUserCountryByIp(string ip)
{
    IpInfo ipInfo = new IpInfo();
    try
    {
        string info = new WebClient().DownloadString("http://ipinfo.io/" + ip);
        ipInfo = JsonConvert.DeserializeObject<IpInfo>(info);
        RegionInfo myRI1 = new RegionInfo(ipInfo.Country);
        ipInfo.Country = myRI1.EnglishName;
    }
    catch (Exception)
    {
        ipInfo.Country = null;
    }
    
    return ipInfo.Country;
}

And the IpInfo Class I used:

public class IpInfo
{
    [JsonProperty("ip")]
    public string Ip { get; set; }

    [JsonProperty("hostname")]
    public string Hostname { get; set; }

    [JsonProperty("city")]
    public string City { get; set; }

    [JsonProperty("region")]
    public string Region { get; set; }

    [JsonProperty("country")]
    public string Country { get; set; }

    [JsonProperty("loc")]
    public string Loc { get; set; }

    [JsonProperty("org")]
    public string Org { get; set; }

    [JsonProperty("postal")]
    public string Postal { get; set; }
}

How do I launch a Git Bash window with particular working directory using a script?

Another option is to create a shortcut with the following properties:

enter image description here

Target should be:

"%SYSTEMDRIVE%\Program Files (x86)\Git\bin\sh.exe" --login

Start in is the folder you wish your Git Bash prompt to launch into.

Foreign key constraints: When to use ON UPDATE and ON DELETE

Do not hesitate to put constraints on the database. You'll be sure to have a consistent database, and that's one of the good reasons to use a database. Especially if you have several applications requesting it (or just one application but with a direct mode and a batch mode using different sources).

With MySQL you do not have advanced constraints like you would have in postgreSQL but at least the foreign key constraints are quite advanced.

We'll take an example, a company table with a user table containing people from theses company

CREATE TABLE COMPANY (
     company_id INT NOT NULL,
     company_name VARCHAR(50),
     PRIMARY KEY (company_id)
) ENGINE=INNODB;

CREATE TABLE USER (
     user_id INT, 
     user_name VARCHAR(50), 
     company_id INT,
     INDEX company_id_idx (company_id),
     FOREIGN KEY (company_id) REFERENCES COMPANY (company_id) ON...
) ENGINE=INNODB;

Let's look at the ON UPDATE clause:

  • ON UPDATE RESTRICT : the default : if you try to update a company_id in table COMPANY the engine will reject the operation if one USER at least links on this company.
  • ON UPDATE NO ACTION : same as RESTRICT.
  • ON UPDATE CASCADE : the best one usually : if you update a company_id in a row of table COMPANY the engine will update it accordingly on all USER rows referencing this COMPANY (but no triggers activated on USER table, warning). The engine will track the changes for you, it's good.
  • ON UPDATE SET NULL : if you update a company_id in a row of table COMPANY the engine will set related USERs company_id to NULL (should be available in USER company_id field). I cannot see any interesting thing to do with that on an update, but I may be wrong.

And now on the ON DELETE side:

  • ON DELETE RESTRICT : the default : if you try to delete a company_id Id in table COMPANY the engine will reject the operation if one USER at least links on this company, can save your life.
  • ON DELETE NO ACTION : same as RESTRICT
  • ON DELETE CASCADE : dangerous : if you delete a company row in table COMPANY the engine will delete as well the related USERs. This is dangerous but can be used to make automatic cleanups on secondary tables (so it can be something you want, but quite certainly not for a COMPANY<->USER example)
  • ON DELETE SET NULL : handful : if you delete a COMPANY row the related USERs will automatically have the relationship to NULL. If Null is your value for users with no company this can be a good behavior, for example maybe you need to keep the users in your application, as authors of some content, but removing the company is not a problem for you.

usually my default is: ON DELETE RESTRICT ON UPDATE CASCADE. with some ON DELETE CASCADE for track tables (logs--not all logs--, things like that) and ON DELETE SET NULL when the master table is a 'simple attribute' for the table containing the foreign key, like a JOB table for the USER table.

Edit

It's been a long time since I wrote that. Now I think I should add one important warning. MySQL has one big documented limitation with cascades. Cascades are not firing triggers. So if you were over confident enough in that engine to use triggers you should avoid cascades constraints.

MySQL triggers activate only for changes made to tables by SQL statements. They do not activate for changes in views, nor by changes to tables made by APIs that do not transmit SQL statements to the MySQL Server

==> See below the last edit, things are moving on this domain

Triggers are not activated by foreign key actions.

And I do not think this will get fixed one day. Foreign key constraints are managed by the InnoDb storage and Triggers are managed by the MySQL SQL engine. Both are separated. Innodb is the only storage with constraint management, maybe they'll add triggers directly in the storage engine one day, maybe not.

But I have my own opinion on which element you should choose between the poor trigger implementation and the very useful foreign keys constraints support. And once you'll get used to database consistency you'll love PostgreSQL.

12/2017-Updating this Edit about MySQL:

as stated by @IstiaqueAhmed in the comments, the situation has changed on this subject. So follow the link and check the real up-to-date situation (which may change again in the future).

Vue component event after render

updated might be what you're looking for. https://vuejs.org/v2/api/#updated

jQuery first child of "this"

I've added jsperf test to see the speed difference for different approaches to get the first child (total 1000+ children)

given, notif = $('#foo')

jQuery ways:

  1. $(":first-child", notif) - 4,304 ops/sec - fastest
  2. notif.children(":first") - 653 ops/sec - 85% slower
  3. notif.children()[0] - 1,416 ops/sec - 67% slower

Native ways:

  1. JavaScript native' ele.firstChild - 4,934,323 ops/sec (all the above approaches are 100% slower compared to firstChild)
  2. Native DOM ele from jQery: notif[0].firstChild - 4,913,658 ops/sec

So, first 3 jQuery approaches are not recommended, at least for first-child (I doubt that would be the case with many other too). If you have a jQuery object and need to get the first-child, then get the native DOM element from the jQuery object, using array reference [0] (recommended) or .get(0) and use the ele.firstChild. This gives the same identical results as regular JavaScript usage.

all tests are done in Chrome Canary build v15.0.854.0

How do I enable C++11 in gcc?

If you are using sublime then this code may work if you add it in build as code for building system. You can use this link for more information.

{
    "shell_cmd": "g++ \"${file}\" -std=c++1y -o \"${file_path}/${file_base_name}\"",
    "file_regex": "^(..[^:]*):([0-9]+):?([0-9]+)?:? (.*)$",
    "working_dir": "${file_path}",
    "selector": "source.c, source.c++",

    "variants":
    [
        {
            "name": "Run",
            "shell_cmd": "g++ \"${file}\" -std=c++1y -o \"${file_path}/${file_base_name}\" && \"${file_path}/${file_base_name}\""
        }
    ]
}

How do I plot in real-time in a while loop using matplotlib?

Here's the working version of the code in question (requires at least version Matplotlib 1.1.0 from 2011-11-14):

import numpy as np
import matplotlib.pyplot as plt

plt.axis([0, 10, 0, 1])

for i in range(10):
    y = np.random.random()
    plt.scatter(i, y)
    plt.pause(0.05)

plt.show()

Note some of the changes:

  1. Call plt.pause(0.05) to both draw the new data and it runs the GUI's event loop (allowing for mouse interaction).

.Net picking wrong referenced assembly version

This error was somewhat misleading - I was loading some DLLs that required x64 architecture to be specified. In the .csproj file:

<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release-ABC|AnyCPU'">
    <OutputPath>bin\Release-ABC</OutputPath>
    <PlatformTarget>x64</PlatformTarget>
</PropertyGroup>

A missing PlatformTarget caused this error.

How do I escape a reserved word in Oracle?

Oracle normally requires double-quotes to delimit the name of identifiers in SQL statements, e.g.

SELECT "MyColumn" AS "MyColAlias"
FROM "MyTable" "Alias"
WHERE "ThisCol" = 'That Value';

However, it graciously allows omitting the double-quotes, in which case it quietly converts the identifier to uppercase:

SELECT MyColumn AS MyColAlias
FROM MyTable Alias
WHERE ThisCol = 'That Value';

gets internally converted to something like:

SELECT "ALIAS" . "MYCOLUMN" AS "MYCOLALIAS"
FROM "THEUSER" . "MYTABLE" "ALIAS"
WHERE "ALIAS" . "THISCOL" = 'That Value';

In C#, what is the difference between public, private, protected, and having no access modifier?

Reposting the awesome diagrams from this answer.

Here are all access modifiers in Venn diagrams, from more limiting to more promiscuous:

private:
enter image description here

private protected: - added in C# 7.2
enter image description here

internal:
enter image description here

protected:
enter image description here

protected internal:
enter image description here

public:
enter image description here

Jenkins - Configure Jenkins to poll changes in SCM

I believe best practice these days is H/5 * * * *, which means every 5 minutes with a hashing factor to avoid all jobs starting at EXACTLY the same time.

How to change the display name for LabelFor in razor in mvc3?

This was an old question, but existing answers ignore the serious issue of throwing away any custom attributes when you regenerate the model. I am adding a more detailed answer to cover the current options available.

You have 3 options:

  • Add a [DisplayName("Name goes here")] attribute to the data model class. The downside is that this is thrown away whenever you regenerate the data models.
  • Add a string parameter to your Html.LabelFor. e.g. @Html.LabelFor(model => model.SomekingStatus, "My New Label", new { @class = "control-label"}) Reference: https://msdn.microsoft.com/en-us/library/system.web.mvc.html.labelextensions.labelfor(v=vs.118).aspx The downside to this is that you must repeat the label in every view.
  • Third option. Use a meta-data class attached to the data class (details follow).

Option 3 - Add a Meta-Data Class:

Microsoft allows for decorating properties on an Entity Framework class, without modifying the existing class! This by having meta-data classes that attach to your database classes (effectively a sideways extension of your EF class). This allow attributes to be added to the associated class and not to the class itself so the changes are not lost when you regenerate the data models.

For example, if your data class is MyModel with a SomekingStatus property, you could do it like this:

First declare a partial class of the same name (and using the same namespace), which allows you to add a class attribute without being overridden:

[MetadataType(typeof(MyModelMetaData))]
public partial class MyModel
{
}

All generated data model classes are partial classes, which allow you to add extra properties and methods by simply creating more classes of the same name (this is very handy and I often use it e.g. to provide formatted string versions of other field types in the model).

Step 2: add a metatadata class referenced by your new partial class:

public class MyModelMetaData
{
    // Apply DisplayNameAttribute (or any other attributes)
    [DisplayName("My New Label")]
    public string SomekingStatus;
}

Reference: https://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.metadatatypeattribute(v=vs.110).aspx

Notes:

  • From memory, if you start using a metadata class, it may ignore existing attributes on the actual class ([required] etc) so you may need to duplicate those in the Meta-data class.
  • This does not operate by magic and will not just work with any classes. The code that looks for UI decoration attributes is designed to look for a meta-data class first.

npm WARN enoent ENOENT: no such file or directory, open 'C:\Users\Nuwanst\package.json'

Delete package.json and package-lock.json file

Then type npm init

after that type npm install socket.io --save

finally type npm install

It works for me

How to calculate probability in a normal distribution given mean & standard deviation?

Scipy.stats is a great module. Just to offer another approach, you can calculate it directly using

import math
def normpdf(x, mean, sd):
    var = float(sd)**2
    denom = (2*math.pi*var)**.5
    num = math.exp(-(float(x)-float(mean))**2/(2*var))
    return num/denom

This uses the formula found here: http://en.wikipedia.org/wiki/Normal_distribution#Probability_density_function

to test:

>>> normpdf(7,5,5)  
0.07365402806066466
>>> norm(5,5).pdf(7)
0.073654028060664664

How can I delete one element from an array by value

Here are some benchmarks:

require 'fruity'


class Array          
  def rodrigo_except(*values)
    self - values
  end    

  def niels_except value
    value = value.kind_of?(Array) ? value : [value]
    self - value
  end
end

ARY = [2,4,6,3,8]

compare do
  soziev  { a = ARY.dup; a.delete(3);               a }
  steve   { a = ARY.dup; a -= [3];                  a }
  barlop  { a = ARY.dup; a.delete_if{ |i| i == 3 }; a }
  rodrigo { a = ARY.dup; a.rodrigo_except(3);         }
  niels   { a = ARY.dup; a.niels_except(3);           }
end

# >> Running each test 4096 times. Test will take about 2 seconds.
# >> soziev is similar to barlop
# >> barlop is faster than steve by 2x ± 1.0
# >> steve is faster than rodrigo by 4x ± 1.0
# >> rodrigo is similar to niels

And again with a bigger array containing lots of duplicates:

class Array          
  def rodrigo_except(*values)
    self - values
  end    

  def niels_except value
    value = value.kind_of?(Array) ? value : [value]
    self - value
  end
end

ARY = [2,4,6,3,8] * 1000

compare do
  soziev  { a = ARY.dup; a.delete(3);               a }
  steve   { a = ARY.dup; a -= [3];                  a }
  barlop  { a = ARY.dup; a.delete_if{ |i| i == 3 }; a }
  rodrigo { a = ARY.dup; a.rodrigo_except(3);         }
  niels   { a = ARY.dup; a.niels_except(3);           }
end

# >> Running each test 16 times. Test will take about 1 second.
# >> steve is faster than soziev by 30.000000000000004% ± 10.0%
# >> soziev is faster than barlop by 50.0% ± 10.0%
# >> barlop is faster than rodrigo by 3x ± 0.1
# >> rodrigo is similar to niels

And even bigger with more duplicates:

class Array          
  def rodrigo_except(*values)
    self - values
  end    

  def niels_except value
    value = value.kind_of?(Array) ? value : [value]
    self - value
  end
end

ARY = [2,4,6,3,8] * 100_000

compare do
  soziev  { a = ARY.dup; a.delete(3);               a }
  steve   { a = ARY.dup; a -= [3];                  a }
  barlop  { a = ARY.dup; a.delete_if{ |i| i == 3 }; a }
  rodrigo { a = ARY.dup; a.rodrigo_except(3);         }
  niels   { a = ARY.dup; a.niels_except(3);           }
end

# >> Running each test once. Test will take about 6 seconds.
# >> steve is similar to soziev
# >> soziev is faster than barlop by 2x ± 0.1
# >> barlop is faster than niels by 3x ± 1.0
# >> niels is similar to rodrigo

SQL Server 2012 Install or add Full-text search

You can add full text to an existing instance by changing the SQL Server program in Programs and Features. Follow the steps below. You might need the original disk or ISO for the installation to complete. (Per HotN's comment: If you have SQL Server Express, make sure it is SQL Server Express With Advanced Services.)

Directions:

  1. Open the Programs and Features control panel.
  2. Select Microsoft SQL Server 2012 and click Change.
  3. When prompted to Add/Repair/Remove, select Add.
  4. Advance through the wizard until the Feature Selection screen. Then select Full-Text Search.

Step 1 Step 2

enter image description here

  1. On the Installation Type screen, select the appropriate SQL Server instance.

  2. Advance through the rest of the wizard.

Source (with screenshots): http://www.techrepublic.com/blog/networking/adding-sql-full-text-search-to-an-existing-sql-server/5546

How to remove the arrows from input[type="number"] in Opera

There is no way.

This question is basically a duplicate of Is there a way to hide the new HTML5 spinbox controls shown in Google Chrome & Opera? but maybe not a full duplicate, since the motivation is given.

If the purpose is “browser's awareness of the content being purely numeric”, then you need to consider what that would really mean. The arrows, or spinners, are part of making numeric input more comfortable in some cases. Another part is checking that the content is a valid number, and on browsers that support HTML5 input enhancements, you might be able to do that using the pattern attribute. That attribute may also affect a third input feature, namely the type of virtual keyboard that may appear.

For example, if the input should be exactly five digits (like postal numbers might be, in some countries), then <input type="text" pattern="[0-9]{5}"> could be adequate. It is of course implementation-dependent how it will be handled.

No templates in Visual Studio 2017

I had to reinstall .NET desktop development (throught Workload tab), even button was showing: Modify

After that Visual C# selection appeared :) (And now i can use Console APP Template)

How can I change my default database in SQL Server without using MS SQL Server Management Studio?

What you can do is set your default database using the sp_defaultdb system stored procedure. Log in as you have done and then click the New Query button. After that simply run the sp_defaultdb command as follows:

Exec sp_defaultdb @loginame='login', @defdb='master' 

Call PowerShell script PS1 from another PS1 script inside Powershell ISE

To execute easily a script file in the same folder (or subfolder of) as the caller you can use this:

# Get full path to the script:
$ScriptRoute = [System.IO.Path]::GetFullPath([System.IO.Path]::Combine($PSScriptRoot, "Scriptname.ps1"))

# Execute script at location:
&"$ScriptRoute"

node-request - Getting error "SSL23_GET_SERVER_HELLO:unknown protocol"

I had this problem (403 error for each package) and I found nothing great in the internet to solve it. My .npmrc file inside my user folder was wrong and misunderstood. I changed this npmrc line from

proxy=http://XX.XX.XXX.XXX:XXX/

to :

proxy = XX.XX.XXX.XXX:XXXX

How to break line in JavaScript?

Here you are ;-)

<script type="text/javascript">
    alert("Hello there.\nI am on a second line ;-)")
</script>

Options for initializing a string array

Basic:

string[] myString = new string[]{"string1", "string2"};

or

string[] myString = new string[4];
myString[0] = "string1"; // etc.

Advanced: From a List

list<string> = new list<string>(); 
//... read this in from somewhere
string[] myString = list.ToArray();

From StringCollection

StringCollection sc = new StringCollection();
/// read in from file or something
string[] myString = sc.ToArray();

Extracting specific columns from a data frame

You can subset using a vector of column names. I strongly prefer this approach over those that treat column names as if they are object names (e.g. subset()), especially when programming in functions, packages, or applications.

# data for reproducible example
# (and to avoid confusion from trying to subset `stats::df`)
df <- setNames(data.frame(as.list(1:5)), LETTERS[1:5])
# subset
df[c("A","B","E")]

Note there's no comma (i.e. it's not df[,c("A","B","C")]). That's because df[,"A"] returns a vector, not a data frame. But df["A"] will always return a data frame.

str(df["A"])
## 'data.frame':    1 obs. of  1 variable:
## $ A: int 1
str(df[,"A"])  # vector
##  int 1

Thanks to David Dorchies for pointing out that df[,"A"] returns a vector instead of a data.frame, and to Antoine Fabri for suggesting a better alternative (above) to my original solution (below).

# subset (original solution--not recommended)
df[,c("A","B","E")]  # returns a data.frame
df[,"A"]             # returns a vector

UICollectionView auto scroll to cell at IndexPath

I totally agree with the above answer. The only thing is that for me the solution was set the code in viewDidAppear

viewDidAppear 
{
    [self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredVertically animated:YES];
}

When I used the viewWillAppear the scrolling didn't work.

How to enable named/bind/DNS full logging?

I usually expand each log out into it's own channel and then to a separate log file, certainly makes things easier when you are trying to debug specific issues. So my logging section looks like the following:

logging {
    channel default_file {
        file "/var/log/named/default.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel general_file {
        file "/var/log/named/general.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel database_file {
        file "/var/log/named/database.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel security_file {
        file "/var/log/named/security.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel config_file {
        file "/var/log/named/config.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel resolver_file {
        file "/var/log/named/resolver.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel xfer-in_file {
        file "/var/log/named/xfer-in.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel xfer-out_file {
        file "/var/log/named/xfer-out.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel notify_file {
        file "/var/log/named/notify.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel client_file {
        file "/var/log/named/client.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel unmatched_file {
        file "/var/log/named/unmatched.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel queries_file {
        file "/var/log/named/queries.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel network_file {
        file "/var/log/named/network.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel update_file {
        file "/var/log/named/update.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel dispatch_file {
        file "/var/log/named/dispatch.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel dnssec_file {
        file "/var/log/named/dnssec.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel lame-servers_file {
        file "/var/log/named/lame-servers.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };

    category default { default_file; };
    category general { general_file; };
    category database { database_file; };
    category security { security_file; };
    category config { config_file; };
    category resolver { resolver_file; };
    category xfer-in { xfer-in_file; };
    category xfer-out { xfer-out_file; };
    category notify { notify_file; };
    category client { client_file; };
    category unmatched { unmatched_file; };
    category queries { queries_file; };
    category network { network_file; };
    category update { update_file; };
    category dispatch { dispatch_file; };
    category dnssec { dnssec_file; };
    category lame-servers { lame-servers_file; };
};

Hope this helps.

How to get distinct values from an array of objects in JavaScript?

Simple distinct filter using Maps :

_x000D_
_x000D_
let array = 
    [
        {"name":"Joe", "age":17}, 
        {"name":"Bob", "age":17}, 
        {"name":"Carl", "age": 35}
    ];

let data = new Map();

for (let obj of array) {
  data.set(obj.age, obj);
}

let out = [...data.values()];

console.log(out);
_x000D_
_x000D_
_x000D_

ASP.NET MVC Razor: How to render a Razor Partial View's HTML inside the controller action

I saw that someone was wondering how to do it for another controller.

In my case I had all of my email templates in the Views/Email folder, but you could modify this to pass in the controller in which you have views associated for.

public static string RenderViewToString(Controller controller, string viewName, object model)
    {
        var oldController = controller.RouteData.Values["controller"].ToString();

        if (controller.GetType() != typeof(EmailController))
            controller.RouteData.Values["controller"] = "Email";

        var oldModel = controller.ViewData.Model;
        controller.ViewData.Model = model;
        try
        {
            using (var sw = new StringWriter())
            {
                var viewResult = ViewEngines.Engines.FindView(controller.ControllerContext, viewName,
                                                                           null);

                var viewContext = new ViewContext(controller.ControllerContext, viewResult.View, controller.ViewData, controller.TempData, sw);
                viewResult.View.Render(viewContext, sw);

                //Cleanup
                controller.ViewData.Model = oldModel;
                controller.RouteData.Values["controller"] = oldController;

                return sw.GetStringBuilder().ToString();
            }
        }
        catch (Exception ex)
        {
            Elmah.ErrorSignal.FromCurrentContext().Raise(ex);

            throw ex;
        }
    }

Essentially what this does is take a controller, such as AccountController and modify it to think it's an EmailController so that the code will look in the Views/Email folder. It's necessary to do this because the FindView method doesn't take a straight up path as a parameter, it wants a ControllerContext.

Once done rendering the string, it returns the AccountController back to its initial state to be used by the Response object.

Enable/Disable a dropdownbox in jquery

$(document).ready(function() {
 $('#chkdwn2').click(function() {
   if ($('#chkdwn2').prop('checked')) {
      $('#dropdown').prop('disabled', true);
   } else {
      $('#dropdown').prop('disabled', false);  
   }
 });
});

making use of .prop in the if statement.

Error when creating a new text file with python?

If the file does not exists, open(name,'r+') will fail.

You can use open(name, 'w'), which creates the file if the file does not exist, but it will truncate the existing file.

Alternatively, you can use open(name, 'a'); this will create the file if the file does not exist, but will not truncate the existing file.

Run script with rc.local: script works, but not at boot

I found that because I was using a network-oriented command in my rc.local, sometimes it would fail. I fixed this by putting sleep 3 at the top of my script. I don't know why but it seems when the script is run the network interfaces aren't properly configured or something, and this just allows some time for the DHCP server or something. I don't fully understand but I suppose you could give it a try.

Check if PHP-page is accessed from an iOS device

preg_match("/iPhone|Android|iPad|iPod|webOS/", $_SERVER['HTTP_USER_AGENT'], $matches);
$os = current($matches);

switch($os){
   case 'iPhone': /*do something...*/ break;
   case 'Android': /*do something...*/ break;
   case 'iPad': /*do something...*/ break;
   case 'iPod': /*do something...*/ break;
   case 'webOS': /*do something...*/ break;
}

Python truncate a long string

       >>> info = lambda data: len(data)>10 and data[:10]+'...' or data
       >>> info('sdfsdfsdfsdfsdfsdfsdfsdfsdfsdfsdf')
           'sdfsdfsdfs...'
       >>> info('sdfsdf')
           'sdfsdf'
       >>> 

Python: how can I check whether an object is of type datetime.date?

In Python 3.5, isinstance(x, date) works to me:

>>> from datetime import date
>>> x = date(2012, 9, 1)
>>> type(x)
<class 'datetime.date'>
>>> isinstance(x, date)
True
>>> type(x) is date
True

How can I convert a std::string to int?

there is another easy way : suppose you have a character like c='4' therefore you can do one of these steps :

1st : int q

q=(int) c ; (q is now 52 in ascii table ) . q=q-48; remember that adding 48 to digits is their ascii code .

the second way :

q=c-'0'; the same , character '0' means 48

Eclipse "this compilation unit is not on the build path of a java project"

What i did is after importing the project from svn , deleted the project from workspace and imported it as a maven project from local . Then in preferences->maven->usersettings->in usersettings box gave path of settings.xml which will be in apache maven folder-> conf->settings.xml

and it solved the issue for me.

How to execute Table valued function

You can execute it just as you select a table using SELECT clause. In addition you can provide parameters within parentheses.

Try with below syntax:

SELECT * FROM yourFunctionName(parameter1, parameter2)

What is the difference between a candidate key and a primary key?

A primary key is a column (or columns) in a table that uniquely identifies the rows in that table.

CUSTOMERS


CustomerNo  FirstName   LastName
1   Sally   Thompson
2   Sally   Henderson
3   Harry   Henderson
4   Sandra  Wellington

For example, in the table above, CustomerNo is the primary key.

The values placed in primary key columns must be unique for each row: no duplicates can be tolerated. In addition, nulls are not allowed in primary key columns.

So, having told you that it is possible to use one or more columns as a primary key, how do you decide which columns (and how many) to choose?

Well there are times when it is advisable or essential to use multiple columns. However, if you cannot see an immediate reason to use multiple columns, then use one. This isn't an absolute rule, it is simply advice. However, primary keys made up of single columns are generally easier to maintain and faster in operation. This means that if you query the database, you will usually get the answer back faster if the tables have single column primary keys.

Next question — which column should you pick? The easiest way to choose a column as a primary key (and a method that is reasonably commonly employed) is to get the database itself to automatically allocate a unique number to each row.

In a table of employees, clearly any column like FirstName is a poor choice since you cannot control employee's first names. Often there is only one choice for the primary key, as in the case above. However, if there is more than one, these can be described as 'candidate keys' — the name reflects that they are candidates for the responsible job of primary key.

rsync error: failed to set times on "/foo/bar": Operation not permitted

I've seen that problem when I'm writing to a filesystem which doesn't (properly) handle times -- I think SMB shares or FAT or something.

What is your target filesystem?

Styling HTML email for Gmail

Use inline styles for everything. This site will convert your classes to inline styles: http://premailer.dialect.ca/

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

ERROR 1396 (HY000): Operation CREATE USER failed for 'jack'@'localhost'

I recently got this error.

What worked for me is checking in the mysql workbench 'Users and Privileges' and realizing user still existed.

After deleting it from there, I was able to recreate the user.

How to get current timestamp in string format in Java? "yyyy.MM.dd.HH.mm.ss"

You can use the following

new java.sql.Timestamp(System.currentTimeMillis()).getTime()

Result : 1539594988651

Hope this will help. Just my suggestion and not for reward points.

C# How to change font of a label

I noticed there was not an actual full code answer, so as i come across this, i have created a function, that does change the font, which can be easily modified. I have tested this in

- XP SP3 and Win 10 Pro 64

private void SetFont(Form f, string name, int size, FontStyle style)
{
    Font replacementFont = new Font(name, size, style);
    f.Font = replacementFont;
}

Hint: replace Form to either Label, RichTextBox, TextBox, or any other relative control that uses fonts to change the font on them. By using the above function thus making it completely dynamic.

    /// To call the function do this.
    /// e.g in the form load event etc.

public Form1()
{
      InitializeComponent();
      SetFont(this, "Arial", 8, FontStyle.Bold);  
      // This sets the whole form and 
      // everything below it.
      // Shaun Cassidy.
}

You can also, if you want a full libary so you dont have to code all the back end bits, you can download my dll from Github.

Github DLL

/// and then import the namespace
using Droitech.TextFont;

/// Then call it using:
TextFontClass fClass = new TextFontClass();
fClass.SetFont(this, "Arial", 8, FontStyle.Bold);

Simple.

Python circular importing?

I was able to import the module within the function (only) that would require the objects from this module:

def my_func():
    import Foo
    foo_instance = Foo()

Python convert object to float

  • You can use pandas.Series.astype
  • You can do something like this :

    weather["Temp"] = weather.Temp.astype(float)
    
  • You can also use pd.to_numeric that will convert the column from object to float

  • For details on how to use it checkout this link :http://pandas.pydata.org/pandas-docs/version/0.20/generated/pandas.to_numeric.html
  • Example :

    s = pd.Series(['apple', '1.0', '2', -3])
    print(pd.to_numeric(s, errors='ignore'))
    print("=========================")
    print(pd.to_numeric(s, errors='coerce'))
    
  • Output:

    0    apple
    1      1.0
    2        2
    3       -3
    =========================
    dtype: object
    0    NaN
    1    1.0
    2    2.0
    3   -3.0
    dtype: float64
    
  • In your case you can do something like this:

    weather["Temp"] = pd.to_numeric(weather.Temp, errors='coerce')
    
  • Other option is to use convert_objects
  • Example is as follows

    >> pd.Series([1,2,3,4,'.']).convert_objects(convert_numeric=True)
    
    0     1
    1     2
    2     3
    3     4
    4   NaN
    dtype: float64
    
  • You can use this as follows:

    weather["Temp"] = weather.Temp.convert_objects(convert_numeric=True)
    
  • I have showed you examples because if any of your column won't have a number then it will be converted to NaN... so be careful while using it.

Loop backwards using indices in Python?

Another solution:

z = 10
for x in range (z):
   y = z-x
   print y

Result:

10
9
8
7
6
5
4
3
2
1

Tip: If you are using this method to count back indices in a list, you will want to -1 from the 'y' value, as your list indices will begin at 0.

How do I catch a numpy warning like it's an exception (not just for testing)?

Remove warnings.filterwarnings and add:

numpy.seterr(all='raise')

Joining two table entities in Spring Data JPA

@Query("SELECT rd FROM ReleaseDateType rd, CacheMedia cm WHERE ...")

'0000-00-00 00:00:00' can not be represented as java.sql.Timestamp error

just cast the field as char

Eg: cast(updatedate) as char as updatedate

How do I get the Git commit count?

You are not the first one to think about a "revision number" in Git, but 'wc' is quite dangerous, since commit can be erased or squashed, and the history revisited.

The "revision number" was especially important for Subversion since it was needed in case of merge (SVN1.5 and 1.6 have improved on that front).

You could end up with a pre-commit hook which would include a revision number in the comment, with an algorithm not involving looking up the all history of a branch to determine the correct number.

Bazaar actually came up with such an algorithm , and it may be a good starting point for what you want to do.

(As Bombe's answer points out, Git has actually an algorithm of its own, based on the latest tag, plus the number of commits, plus a bit of an SHA-1 key). You should see (and upvote) his answer if it works for you.


To illustrate Aaron's idea, you can also append the Git commit hash into an application’s "info" file you are distributing with your application.

That way, the about box would look like:

About box

The applicative number is part of the commit, but the 'application’s "info" file' is generated during the packaging process, effectively linking an applicative build number to a technical revision id.

What's the proper value for a checked attribute of an HTML checkbox?

<input ... checked />
<input ... checked="checked" />

Those are equally valid. And in JavaScript:

input.checked = true;
input.setAttribute("checked");
input.setAttribute("checked","checked");

How to fix JSP compiler warning: one JAR was scanned for TLDs yet contained no TLDs?

None of the above worked for me (tomcat 7.0.62)... As Sensei_Shoh notes see the class above the message and add this to logging.properties. My logs were:

Jan 18, 2016 8:44:21 PM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.

so I added

org.apache.catalina.startup.TldConfig.level = FINE

in conf/logging.properties

After that I got so many "offending" files that I did not bother skipping them (and also reverted to normal logging...)

How do I get the current date in Cocoa

+ (NSString *)displayCurrentTimeWithAMPM 
{
    NSDateFormatter *outputFormatter = [[NSDateFormatter alloc] init];
    [outputFormatter setDateFormat:@"h:mm aa"];

    NSString *dateTime = [NSString stringWithFormat:@"%@",[outputFormatter stringFromDate:[NSDate date]]];

    return dateTime;
}

return 3:33 AM

Calling Javascript function from server side

You can call the function from code behind like this :

MyForm.aspx.cs

protected void MyButton_Click(object sender, EventArgs e)
{
    Page.ClientScript.RegisterStartupScript(this.GetType(), "myScript", "AnotherFunction();", true);
}

MyForm.aspx

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>My Page</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
    function Test() {
        alert("hi");
        $("#ButtonRow").show();
    }
    function AnotherFunction()
    {
        alert("This is another function");
    }
</script>
</head>
<body>
<form id="form2" runat="server">
<table>
    <tr><td>
            <asp:RadioButtonList ID="SearchCategory" runat="server" onchange="Test()"  RepeatDirection="Horizontal"  BorderStyle="Solid">
               <asp:ListItem>Merchant</asp:ListItem>
               <asp:ListItem>Store</asp:ListItem>
               <asp:ListItem>Terminal</asp:ListItem>
            </asp:RadioButtonList>
        </td>
    </tr>
    <tr id="ButtonRow"style="display:none">
         <td>
            <asp:Button ID="MyButton" runat="server" Text="Click Here" OnClick="MyButton_Click" />
        </td>
    </tr>
    </table> 
</form>

Why is HttpClient BaseAddress not working?

Reference Resolution is described by RFC 3986 Uniform Resource Identifier (URI): Generic Syntax. And that is exactly how it supposed to work. To preserve base URI path you need to add slash at the end of the base URI and remove slash at the beginning of relative URI.

If base URI contains non-empty path, merge procedure discards it's last part (after last /). Relevant section:

5.2.3. Merge Paths

The pseudocode above refers to a "merge" routine for merging a relative-path reference with the path of the base URI. This is accomplished as follows:

  • If the base URI has a defined authority component and an empty path, then return a string consisting of "/" concatenated with the reference's path; otherwise

  • return a string consisting of the reference's path component appended to all but the last segment of the base URI's path (i.e., excluding any characters after the right-most "/" in the base URI path, or excluding the entire base URI path if it does not contain any "/" characters).

If relative URI starts with a slash, it is called a absolute-path relative URI. In this case merge procedure ignore all base URI path. For more information check 5.2.2. Transform References section.

How do I define a method in Razor?

You can simply declare them as local functions in a razor block (i.e. @{}).

@{
    int Add(int x, int y)
    {
        return x + y;
    }
}

<div class="container">
    <p>
        @Add(2, 5)
    </p>
</div>

Adding one day to a date

The following code get the first day of January of current year (but it can be a another date) and add 365 days to that day (but it can be N number of days) using DateTime class and its method modify() and format():

echo (new DateTime((new DateTime())->modify('first day of January this year')->format('Y-m-d')))->modify('+365 days')->format('Y-m-d');

how to move elasticsearch data from one server to another

We can use elasticdump or multielasticdump to take the backup and restore it, We can move data from one server/cluster to another server/cluster.

Please find a detailed answer which I have provided here.

querying WHERE condition to character length?

Sorry, I wasn't sure which SQL platform you're talking about:

In MySQL:

$query = ("SELECT * FROM $db WHERE conditions AND LENGTH(col_name) = 3");

in MSSQL

$query = ("SELECT * FROM $db WHERE conditions AND LEN(col_name) = 3");

The LENGTH() (MySQL) or LEN() (MSSQL) function will return the length of a string in a column that you can use as a condition in your WHERE clause.

Edit

I know this is really old but thought I'd expand my answer because, as Paulo Bueno rightly pointed out, you're most likely wanting the number of characters as opposed to the number of bytes. Thanks Paulo.

So, for MySQL there's the CHAR_LENGTH(). The following example highlights the difference between LENGTH() an CHAR_LENGTH():

CREATE TABLE words (
    word VARCHAR(100)
) ENGINE INNODB DEFAULT CHARSET utf8mb4 COLLATE utf8mb4_unicode_ci;

INSERT INTO words(word) VALUES('??'), ('happy'), ('hayir');

SELECT word, LENGTH(word) as num_bytes, CHAR_LENGTH(word) AS num_characters FROM words;

+--------+-----------+----------------+
| word   | num_bytes | num_characters |
+--------+-----------+----------------+
| ??    |         6 |              2 |
| happy  |         5 |              5 |
| hayir  |         6 |              5 |
+--------+-----------+----------------+

Be careful if you're dealing with multi-byte characters.

Sync data between Android App and webserver

one way to accomplish this to have a server side application that waits for the data. The data can be sent using HttpRequest objects in Java or you can write your own TCP/IP data transfer utility. Data can be sent using JSON format or any other format that you think is suitable. Also data can be encrypted before sending to server if it contains sensitive information. All Server application have to do is just wait for HttpRequests to come in and parse the data and store it anywhere you want.

browser sessionStorage. share between tabs?

You can use localStorage and its "storage" eventListener to transfer sessionStorage data from one tab to another.

This code would need to exist on ALL tabs. It should execute before your other scripts.

// transfers sessionStorage from one tab to another
var sessionStorage_transfer = function(event) {
  if(!event) { event = window.event; } // ie suq
  if(!event.newValue) return;          // do nothing if no value to work with
  if (event.key == 'getSessionStorage') {
    // another tab asked for the sessionStorage -> send it
    localStorage.setItem('sessionStorage', JSON.stringify(sessionStorage));
    // the other tab should now have it, so we're done with it.
    localStorage.removeItem('sessionStorage'); // <- could do short timeout as well.
  } else if (event.key == 'sessionStorage' && !sessionStorage.length) {
    // another tab sent data <- get it
    var data = JSON.parse(event.newValue);
    for (var key in data) {
      sessionStorage.setItem(key, data[key]);
    }
  }
};

// listen for changes to localStorage
if(window.addEventListener) {
  window.addEventListener("storage", sessionStorage_transfer, false);
} else {
  window.attachEvent("onstorage", sessionStorage_transfer);
};


// Ask other tabs for session storage (this is ONLY to trigger event)
if (!sessionStorage.length) {
  localStorage.setItem('getSessionStorage', 'foobar');
  localStorage.removeItem('getSessionStorage', 'foobar');
};

I tested this in chrome, ff, safari, ie 11, ie 10, ie9

This method "should work in IE8" but i could not test it as my IE was crashing every time i opened a tab.... any tab... on any website. (good ol IE) PS: you'll obviously need to include a JSON shim if you want IE8 support as well. :)

Credit goes to this full article: http://blog.guya.net/2015/06/12/sharing-sessionstorage-between-tabs-for-secure-multi-tab-authentication/

How to position text over an image in css

as Harry Joy points out, set the image as the div's background and then, if you only have one line of text you can set the line-height of the text to be the same as the div height and this will place your text in the center of the div.

If you have more than one line you'll want to set the display to be table-cell and vertical-alignment to middle.

Altering user-defined table types in SQL Server

As of my knowledge it is impossible to alter/modify a table type.You can create the type with a different name and then drop the old type and modify it to the new name

Credits to jkrajes

As per msdn, it is like 'The user-defined table type definition cannot be modified after it is created'.

Qt. get part of QString

If you do not need to modify the substring, then you can use QStringRef. The QStringRef class is a read only wrapper around an existing QString that references a substring within the existing string. This gives much better performance than creating a new QString object to contain the sub-string. E.g.

QString myString("This is a string");
QStringRef subString(&myString, 5, 2); // subString contains "is"

If you do need to modify the substring, then left(), mid() and right() will do what you need...

QString myString("This is a string");
QString subString = myString.mid(5,2); // subString contains "is"
subString.append("n't"); // subString contains "isn't"

':app:lintVitalRelease' error when generating signed apk

Just find the error reason in here and fix it.

yourProject/app/build/reports/lint-results-release-fatal.xml

Catch multiple exceptions at once?

Cautioned and Warned: Yet another kind, functional style.

What is in the link doesn't answer your question directly, but it's trivial to extend it to look like:

static void Main() 
{ 
    Action body = () => { ...your code... };

    body.Catch<InvalidOperationException>() 
        .Catch<BadCodeException>() 
        .Catch<AnotherException>(ex => { ...handler... })(); 
}

(Basically provide another empty Catch overload which returns itself)

The bigger question to this is why. I do not think the cost outweighs the gain here :)

What is the default access specifier in Java?

Here is a quote about package level visibility from an interview with James Gosling, the creator of Java:

Bill Venners: Java has four access levels. The default is package. I have always wondered if making package access default was convenient because the three keywords that people from C++ already knew about were private, protected, and public. Or if you had some particular reason that you felt package access should be the default.

James Gosling: A package is generally a set of things that are kind of written together. So generically I could have done one of two things. One was force you always to put in a keyword that gives you the domain. Or I could have had a default value. And then the question is, what makes a sensible default? And I tend to go for what is the least dangerous thing.

So public would have been a really bad thing to make the default. Private would probably have been a bad thing to make a default, if only because people actually don't write private methods that often. And same thing with protected. And in looking at a bunch of code that I had, I decided that the most common thing that was reasonably safe was in the package. And C++ didn't have a keyword for that, because they didn't have a notion of packages.

But I liked it rather than the friends notion, because with friends you kind of have to enumerate who all of your friends are, and so if you add a new class to a package, then you generally end up having to go to all of the classes in that package and update their friends, which I had always found to be a complete pain in the butt.

But the friends list itself causes sort of a versioning problem. And so there was this notion of a friendly class. And the nice thing that I was making that the default -- I'll solve the problem so what should the keyword be?

For a while there actually was a friendly keyword. But because all the others start with "P," it was "phriendly" with a "PH." But that was only in there for maybe a day.

http://www.artima.com/intv/gosling2P.html

How to get an absolute file path in Python

Update for Python 3.4+ pathlib that actually answers the question:

from pathlib import Path

relative = Path("mydir/myfile.txt")
absolute = relative.absolute()  # absolute is a Path object

If you only need a temporary string, keep in mind that you can use Path objects with all the relevant functions in os.path, including of course abspath:

from os.path import abspath

absolute = abspath(relative)  # absolute is a str object

How do you run a SQL Server query from PowerShell?

You can use the Invoke-Sqlcmd cmdlet

Invoke-Sqlcmd -Query "SELECT GETDATE() AS TimeOfQuery;" -ServerInstance "MyComputer\MyInstance"

http://technet.microsoft.com/en-us/library/cc281720.aspx

How to get the Facebook user id using the access token

in FacebookSDK v2.1 (I can't check older version). We have

NSString *currentUserFBID = [FBSession activeSession].accessTokenData.userID;

However according to the comment in FacebookSDK

@discussion This may not be populated for login behaviours such as the iOS system account.

So may be you should check if it is available, and then whether use it, or call the request to get the user id

Convert a Unicode string to a string in Python (containing extra symbols)

Well, if you're willing/ready to switch to Python 3 (which you may not be due to the backwards incompatibility with some Python 2 code), you don't have to do any converting; all text in Python 3 is represented with Unicode strings, which also means that there's no more usage of the u'<text>' syntax. You also have what are, in effect, strings of bytes, which are used to represent data (which may be an encoded string).

http://docs.python.org/3.1/whatsnew/3.0.html#text-vs-data-instead-of-unicode-vs-8-bit

(Of course, if you're currently using Python 3, then the problem is likely something to do with how you're attempting to save the text to a file.)

Git: Could not resolve host github.com error while cloning remote repository in git

All, I want to let you all know that I was having this same issue. I solve it by resetting my remote URL git remote set-url origin https://new.url.here I found how to do this from this answer but I had to change hit to https: Change the URI (URL) for a remote Git repository

I can't find my git.exe file in my Github folder

I faced the same issue and was not able to find it out where git.exe is located. After spending so much time I fount that in my windows 8, it is located at

C:\Program Files (x86)\Git\bin

And for command line :

C:\Program Files (x86)\Git\cmd

Hope this helps someone facing the same issue.

Java 'file.delete()' Is not Deleting Specified File

In my case it was the close() that was not executing due to unhandled exception.

void method() throws Exception {
    FileInputStream fis = new FileInputStream(fileName);
    parse(fis);
    fis.close();
}

Assume exception is being thrown on the parse(), which is not handled in this method and therefore the file is not closed, down the road, the file is being deleted, and that delete statement fails, and do not delete.

So, instead I had the code like this, then it worked...

    try {
        parse(fis);
    }
    catch (Exception ex) {
        fis.close();
        throw ex;
    }

so basic Java, which sometimes we overlook.

Find index of a value in an array

Just posted my implementation of IndexWhere() extension method (with unit tests):

http://snipplr.com/view/53625/linq-index-of-item--indexwhere/

Example usage:

int index = myList.IndexWhere(item => item.Something == someOtherThing);

What is Node.js?

I think the advantages are:

  1. Web development in a dynamic language (JavaScript) on a VM that is incredibly fast (V8). It is much faster than Ruby, Python, or Perl.

  2. Ability to handle thousands of concurrent connections with minimal overhead on a single process.

  3. JavaScript is perfect for event loops with first class function objects and closures. People already know how to use it this way having used it in the browser to respond to user initiated events.

  4. A lot of people already know JavaScript, even people who do not claim to be programmers. It is arguably the most popular programming language.

  5. Using JavaScript on a web server as well as the browser reduces the impedance mismatch between the two programming environments which can communicate data structures via JSON that work the same on both sides of the equation. Duplicate form validation code can be shared between server and client, etc.

make: Nothing to be done for `all'

I arrived at this peculiar, hard-to-debug error through a different route. My trouble ended up being that I was using a pattern rule in a build step when the target and the dependency were located in distinct directories. Something like this:

foo/apple.o: bar/apple.c $(FOODEPS)

%.o: %.c
    $(CC) $< -o $@

I had several dependencies set up this way, and was trying to use one pattern recipe for them all. Clearly, a single substitution for "%" isn't going to work here. I made explicit rules for each dependency, and I found myself back among the puppies and unicorns!

foo/apple.o: bar/apple.c $(FOODEPS)
    $(CC) $< -o $@

Hope this helps someone!

String array initialization in Java

First up, this has got nothing to do with String, it is about arrays.. and that too specifically about declarative initialization of arrays.

As discussed by everyone in almost every answer here, you can, while declaring a variable, use:

String names[] = {"x","y","z"};

However, post declaration, if you want to assign an instance of an Array:

names = new String[] {"a","b","c"};

AFAIK, the declaration syntax is just a syntactic sugar and it is not applicable anymore when assigning values to variables because when values are assigned you need to create an instance properly.

However, if you ask us why it is so? Well... good luck getting an answer to that. Unless someone from the Java committee answers that or there is explicit documentation citing the said syntactic sugar.

Using pg_dump to only get insert statements from one table within database

Put into a script I like something like that:

#!/bin/bash
set -o xtrace # remove me after debug
TABLE=some_table_name
DB_NAME=prod_database

BASE_DIR=/var/backups/someDir
LOCATION="${BASE_DIR}/myApp_$(date +%Y%m%d_%H%M%S)"
FNAME="${LOCATION}_${DB_NAME}_${TABLE}.sql"

# Create backups directory if not exists
if [[ ! -e $BASE_DIR ]];then
       mkdir $BASE_DIR
       chown -R postgres:postgres $BASE_DIR
fi

sudo -H -u postgres pg_dump --column-inserts --data-only --table=$TABLE $DB_NAME > $FNAME
sudo gzip $FNAME

Download a working local copy of a webpage

wget is capable of doing what you are asking. Just try the following:

wget -p -k http://www.example.com/

The -p will get you all the required elements to view the site correctly (css, images, etc). The -k will change all links (to include those for CSS & images) to allow you to view the page offline as it appeared online.

From the Wget docs:

‘-k’
‘--convert-links’
After the download is complete, convert the links in the document to make them
suitable for local viewing. This affects not only the visible hyperlinks, but
any part of the document that links to external content, such as embedded images,
links to style sheets, hyperlinks to non-html content, etc.

Each link will be changed in one of the two ways:

    The links to files that have been downloaded by Wget will be changed to refer
    to the file they point to as a relative link.

    Example: if the downloaded file /foo/doc.html links to /bar/img.gif, also
    downloaded, then the link in doc.html will be modified to point to
    ‘../bar/img.gif’. This kind of transformation works reliably for arbitrary
    combinations of directories.

    The links to files that have not been downloaded by Wget will be changed to
    include host name and absolute path of the location they point to.

    Example: if the downloaded file /foo/doc.html links to /bar/img.gif (or to
    ../bar/img.gif), then the link in doc.html will be modified to point to
    http://hostname/bar/img.gif. 

Because of this, local browsing works reliably: if a linked file was downloaded,
the link will refer to its local name; if it was not downloaded, the link will
refer to its full Internet address rather than presenting a broken link. The fact
that the former links are converted to relative links ensures that you can move
the downloaded hierarchy to another directory.

Note that only at the end of the download can Wget know which links have been
downloaded. Because of that, the work done by ‘-k’ will be performed at the end
of all the downloads. 

curl -GET and -X GET

By default you use curl without explicitly saying which request method to use. If you just pass in a HTTP URL like curl http://example.com it will use GET. If you use -d or -F curl will use POST, -I will cause a HEAD and -T will make it a PUT.

If for whatever reason you're not happy with these default choices that curl does for you, you can override those request methods by specifying -X [WHATEVER]. This way you can for example send a DELETE by doing curl -X DELETE [URL].

It is thus pointless to do curl -X GET [URL] as GET would be used anyway. In the same vein it is pointless to do curl -X POST -d data [URL]... But you can make a fun and somewhat rare request that sends a request-body in a GET request with something like curl -X GET -d data [URL].

Digging deeper

curl -GET (using a single dash) is just wrong for this purpose. That's the equivalent of specifying the -G, -E and -T options and that will do something completely different.

There's also a curl option called --get to not confuse matters with either. It is the long form of -G, which is used to convert data specified with -d into a GET request instead of a POST.

(I subsequently used my own answer here to populate the curl FAQ to cover this.)

Warnings

Modern versions of curl will inform users about this unnecessary and potentially harmful use of -X when verbose mode is enabled (-v) - to make users aware. Further explained and motivated in this blog post.

-G converts a POST + body to a GET + query

You can ask curl to convert a set of -d options and instead of sending them in the request body with POST, put them at the end of the URL's query string and issue a GET, with the use of `-G. Like this:

curl -d name=daniel -d grumpy=yes -G https://example.com/

Listview Scroll to the end of the list after updating the list

Supposing you know when the list data has changed, you can manually tell the list to scroll to the bottom by setting the list selection to the last row. Something like:

private void scrollMyListViewToBottom() {
    myListView.post(new Runnable() {
        @Override
        public void run() {
            // Select the last row so it will scroll into view...
            myListView.setSelection(myListAdapter.getCount() - 1);
        }
    });
}

Extract string between two strings in java

Jlordo approach covers specific situation. If you try to build an abstract method out of it, you can face a difficulty to check if 'textFrom' is before 'textTo'. Otherwise method can return a match for some other occurance of 'textFrom' in text.

Here is a ready-to-go abstract method that covers this disadvantage:

  /**
   * Get text between two strings. Passed limiting strings are not 
   * included into result.
   *
   * @param text     Text to search in.
   * @param textFrom Text to start cutting from (exclusive).
   * @param textTo   Text to stop cuutting at (exclusive).
   */
  public static String getBetweenStrings(
    String text,
    String textFrom,
    String textTo) {

    String result = "";

    // Cut the beginning of the text to not occasionally meet a      
    // 'textTo' value in it:
    result =
      text.substring(
        text.indexOf(textFrom) + textFrom.length(),
        text.length());

    // Cut the excessive ending of the text:
    result =
      result.substring(
        0,
        result.indexOf(textTo));

    return result;
  }

Inserting code in this LaTeX document with indentation

Since it wasn't yet mentioned here, it may be worth to add one more option, package spverbatim (no syntax highlighting):

\documentclass{article}
\usepackage{spverbatim}

\begin{document}

\begin{spverbatim}
  Your code here
\end{spverbatim}

\end{document}

Also, if syntax highlighting is not required, package alltt:

\documentclass{article}
\usepackage{alltt}

\begin{document}

\begin{alltt}
  Your code here
\end{alltt}

\end{document}

What's the difference between tilde(~) and caret(^) in package.json?

You probably have seen the tilde (~) and caret (^) in the package.json. What is the difference between them?

When you do npm install moment --save, It saves the entry in the package.json with the caret (^) prefix.

The tilde (~)

In the simplest terms, the tilde (~) matches the most recent minor version (the middle number). ~1.2.3 will match all 1.2.x versions but will miss 1.3.0.

The caret (^)

The caret (^), on the other hand, is more relaxed. It will update you to the most recent major version (the first number). ^1.2.3 will match any 1.x.x release including 1.3.0, but will hold off on 2.0.0.

Reference: https://medium.com/@Hardy2151/caret-and-tilde-in-package-json-57f1cbbe347b

Count length of array and return 1 if it only contains one element

A couple other options:

  1. Use the comma operator to create an array:

    $cars = ,"bmw"
    $cars.GetType().FullName
    # Outputs: System.Object[]
    
  2. Use array subexpression syntax:

    $cars = @("bmw")
    $cars.GetType().FullName
    # Outputs: System.Object[]
    

If you don't want an object array you can downcast to the type you want e.g. a string array.

 [string[]] $cars = ,"bmw"
 [string[]] $cars = @("bmw")

How do I wait for a promise to finish before returning the variable of a function?

You don't want to make the function wait, because JavaScript is intended to be non-blocking. Rather return the promise at the end of the function, then the calling function can use the promise to get the server response.

var promise = query.find(); 
return promise; 

//Or return query.find(); 

OpenCV in Android Studio

In your build.gradle

repositories {
  jcenter()
}

implementation 'com.quickbirdstudios:opencv:4.1.0'

More information

Passing bash variable to jq

It's a quote issue, you need :

projectID=$(
  cat file.json | jq -r ".resource[] | select(.username=='$EMAILID') | .id"
)

If you put single quotes to delimit the main string, the shell takes $EMAILID literally.

"Double quote" every literal that contains spaces/metacharacters and every expansion: "$var", "$(command "$var")", "${array[@]}", "a & b". Use 'single quotes' for code or literal $'s: 'Costs $5 US', ssh host 'echo "$HOSTNAME"'. See
http://mywiki.wooledge.org/Quotes
http://mywiki.wooledge.org/Arguments
http://wiki.bash-hackers.org/syntax/words

How do I use .woff fonts for my website?

After generation of woff files, you have to define font-family, which can be used later in all your css styles. Below is the code to define font families (for normal, bold, bold-italic, italic) typefaces. It is assumed, that there are 4 *.woff files (for mentioned typefaces), placed in fonts subdirectory.

In CSS code:

@font-face {
    font-family: "myfont";
    src: url("fonts/awesome-font.woff") format('woff');
}

@font-face {
    font-family: "myfont";
    src: url("fonts/awesome-font-bold.woff") format('woff');
    font-weight: bold;
}

@font-face {
    font-family: "myfont";
    src: url("fonts/awesome-font-boldoblique.woff") format('woff');
    font-weight: bold;
    font-style: italic;
}

@font-face {
    font-family: "myfont";
    src: url("fonts/awesome-font-oblique.woff") format('woff');
    font-style: italic;
}

After having that definitions, you can just write, for example,

In HTML code:

<div class="mydiv">
    <b>this will be written with awesome-font-bold.woff</b>
    <br/>
    <b><i>this will be written with awesome-font-boldoblique.woff</i></b>
    <br/>
    <i>this will be written with awesome-font-oblique.woff</i>
    <br/>
    this will be written with awesome-font.woff
</div>

In CSS code:

.mydiv {
    font-family: myfont
}

The good tool for generation woff files, which can be included in CSS stylesheets is located here. Not all woff files work correctly under latest Firefox versions, and this generator produces 'correct' fonts.

How do I force files to open in the browser instead of downloading (PDF)?

If you have Apache add this to the .htaccess file:

<FilesMatch "\.(?i:pdf)$">
    ForceType application/octet-stream
    Header set Content-Disposition attachment
</FilesMatch>

R - test if first occurrence of string1 is followed by string2

> grepl("^[^_]+_1",s)
[1] FALSE
> grepl("^[^_]+_2",s)
[1] TRUE

basically, look for everything at the beginning except _, and then the _2.

+1 to @Ananda_Mahto for suggesting grepl instead of grep.

Errors in pom.xml with dependencies (Missing artifact...)

It seemed that a lot of dependencies were incorrect.

enter image description here

Download the whole POM here

A good place to look for the correct dependencies is the Maven Repository website.

Checking whether the pip is installed?

pip list is a shell command. You should run it in your shell (bash/cmd), rather than invoke it from python interpreter.

pip does not provide a stable API. The only supported way of calling it is via subprocess, see docs and the code at the end of this answer.

However, if you want to just check if pip exists locally, without running it, and you are running Linux, I would suggest that you use bash's which command:

which pip

It should show you whether the command can be found in bash's PATH/aliases, and if it does, what does it actually execute.

If running pip is not an issue, you could just do:

python -m pip --version

If you really need to do it from a python script, you can always put the import statement into a try...except block:

try:
    import pip
except ImportError:
    print("Pip not present.")

Or check what's the output of a pip --version using subprocess module:

subprocess.check_call([sys.executable, '-m', 'pip', '--version'])

How to check if a file is a valid image file?

I have just found the builtin imghdr module. From python documentation:

The imghdr module determines the type of image contained in a file or byte stream.

This is how it works:

>>> import imghdr
>>> imghdr.what('/tmp/bass')
'gif'

Using a module is much better than reimplementing similar functionality

How to Consume WCF Service with Android

You will need something more that a http request to interact with a WCF service UNLESS your WCF service has a REST interface. Either look for a SOAP web service API that runs on android or make your service RESTful. You will need .NET 3.5 SP1 to do WCF REST services:

http://msdn.microsoft.com/en-us/netframework/dd547388.aspx

Matching special characters and letters in regex

I tried a bunch of these but none of them worked for all of my tests. So I found this:

^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[^a-zA-Z0-9])(?!.*\s).{8,15}$

from this source: https://www.w3resource.com/javascript/form/password-validation.php

Which Eclipse version should I use for an Android app?

The easiest solution is to download the Android SDK bundle:

http://developer.android.com/sdk/installing/bundle.html

The ADT Bundle provides everything you need to start developing apps, including a version of the Eclipse IDE with built-in ADT (Android Developer Tools) to streamline your Android app development.

"No Content-Security-Policy meta tag found." error in my phonegap application

There is an another issue about connection. Some android versions can connect but some cannot. So there is an another solution

in AndroidManifest.xml:

_x000D_
_x000D_
<application ... android:usesCleartextTraffic="true">_x000D_
        ..._x000D_
    </application>
_x000D_
_x000D_
_x000D_

Just add 'android:usesCleartextTraffic="true"'

and problem solved finally.

INSTALL_FAILED_USER_RESTRICTED : android studio using redmi 4 device

In my case, I pressed Deny unfortunately during first time installation. So I was getting INSTALL_FAILED_USER_RESTRICTED.

You can get modify this permission for app under permissions.

Settings->Permissions->Install via USB->{Your App}

You should have enabled below options too.

Settings->Additional Settings->Privacy->Unknown Sources

Settings->Additional Settings->Developer Options->Install via USB

Get file version in PowerShell

Here an alternative method. It uses Get-WmiObject CIM_DATAFILE to select the version.

(Get-WmiObject -Class CIM_DataFile -Filter "Name='C:\\Windows\\explorer.exe'" | Select-Object Version).Version

Read only file system on Android

adb remount

works for me and seems to be the simplest solution.

Reading a string with spaces with sscanf

Since you want the trailing string from the input, you can use %n (number of characters consumed thus far) to get the position at which the trailing string starts. This avoids memory copies and buffer sizing issues, but comes at the cost that you may need to do them explicitly if you wanted a copy.

const char *input = "19  cool kid";
int age;
int nameStart = 0;
sscanf(input, "%d %n", &age, &nameStart);
printf("%s is %d years old\n", input + nameStart, age);

outputs:

cool kid is 19 years old

Laravel Eloquent update just if changes have been made

You can use getChanges() on Eloquent model even after persisting.

Getting IP address of client

As @martin and this answer explained, it is complicated. There is no bullet-proof way of getting the client's ip address.

The best that you can do is to try to parse "X-Forwarded-For" and rely on request.getRemoteAddr();

public static String getClientIpAddress(HttpServletRequest request) {
    String xForwardedForHeader = request.getHeader("X-Forwarded-For");
    if (xForwardedForHeader == null) {
        return request.getRemoteAddr();
    } else {
        // As of https://en.wikipedia.org/wiki/X-Forwarded-For
        // The general format of the field is: X-Forwarded-For: client, proxy1, proxy2 ...
        // we only want the client
        return new StringTokenizer(xForwardedForHeader, ",").nextToken().trim();
    }
}

The import android.support cannot be resolved

This is very easy step to import any 3rd party lib or jar file into your project

  1. Copy android-support-v4.jar file from your_drive\android-sdks\extras\android\support\v4\android-support-v4.jar
    or copy from your existing project's bin folder.
    or any third party .jar file
  2. paste copied jar file into lib folder

  3. right click on this jar file and then click on build Path->Add to Build Path enter image description here

  4. even still you are getting error in your project then Clean the Project and Build it.

mkdir's "-p" option

Note that -p is an argument to the mkdir command specifically, not the whole of Unix. Every command can have whatever arguments it needs.

In this case it means "parents", meaning mkdir will create a directory and any parents that don't already exist.

Task.Run with Parameter(s)?

I know this is an old thread, but I wanted to share a solution I ended up having to use since the accepted post still has an issue.

The Issue:

As pointed out by Alexandre Severino, if param (in the function below) changes shortly after the function call, you might get some unexpected behavior in MethodWithParameter.

Task.Run(() => MethodWithParameter(param)); 

My Solution:

To account for this, I ended up writing something more like the following line of code:

(new Func<T, Task>(async (p) => await Task.Run(() => MethodWithParam(p)))).Invoke(param);

This allowed me to safely use the parameter asynchronously despite the fact that the parameter changed very quickly after starting the task (which caused issues with the posted solution).

Using this approach, param (value type) gets its value passed in, so even if the async method runs after param changes, p will have whatever value param had when this line of code ran.

Video format or MIME type is not supported

Firefox does not support the MPEG H.264 (mp4) format at this time, due to a philosophical disagreement with the closed-source nature of the format.

To play videos in all browsers without using plugins, you will need to host multiple copies of each video, in different formats. You will also need to use an alternate form of the video tag, as seen in the JSFiddle from @TimHayes above, reproduced below. Mozilla claims that only mp4 and WebM are necessary to ensure complete coverage of all major browsers, but you may wish to consult the Video Formats and Browser Support heading on W3C's HTML5 Video page to see which browser supports what formats.

Additionally, it's worth checking out the HTML5 Video page on Wikipedia for a basic comparison of the major file formats.

Below is the appropriate video tag (you will need to re-encode your video in WebM or OGG formats as well as your existing mp4):

<video id="video" controls='controls'>
  <source src="videos/clip.mp4" type="video/mp4"/>
  <source src="videos/clip.webm" type="video/webm"/>
  <source src="videos/clip.ogv" type="video/ogg"/>
  Your browser doesn't seem to support the video tag.
</video>

Updated Nov. 8, 2013

Network infrastructure giant Cisco has announced plans to open-source an implementation of the H.264 codec, removing the licensing fees that have so far proved a barrier to use by Mozilla. Without getting too deep into the politics of it (see following link for that) this will allow Firefox to support H.264 starting in "early 2014". However, as noted in that link, this still comes with a caveat. The H.264 codec is merely for video, and in the MPEG-4 container it is most commonly paired with the closed-source AAC audio codec. Because of this, playback of H.264 video will work, but audio will depend on whether the end-user has the AAC codec already present on their machine.

The long and short of this is that progress is being made, but you still can't avoid using multiple encodings without using a plugin.

How to declare a global variable in php?

Let's think a little different, You can use static parameters:

class global {
    static $foo = "bar";
}

And you can use and modify it every where you like, like:

function func() {
    echo global::$foo;
}

Update using LINQ to SQL

In the absence of more detailed info:

using(var dbContext = new dbDataContext())
{
    var data = dbContext.SomeTable.SingleOrDefault(row => row.id == requiredId);
    if(data != null)
    {
        data.SomeField = newValue;
    }
    dbContext.SubmitChanges();
}

How can I start pagenumbers, where the first section occurs in LaTex?

To suppress the page number on the first page, add \thispagestyle{empty} after the \maketitle command.

The second page of the document will then be numbered "2". If you want this page to be numbered "1", you can add \pagenumbering{arabic} after the \clearpage command, and this will reset the page number.

Here's a complete minimal example:

\documentclass[notitlepage]{article}

\title{My Report}
\author{My Name}

\begin{document}
\maketitle
\thispagestyle{empty}

\begin{abstract}
\ldots
\end{abstract}

\clearpage
\pagenumbering{arabic} 

\section{First Section}
\ldots

\end{document}

JavaScript error (Uncaught SyntaxError: Unexpected end of input)

Add a second });.

When properly indented, your code reads

$(function() {
    $("#mewlyDiagnosed").hover(function() {
        $("#mewlyDiagnosed").animate({'height': '237px', 'top': "-75px"});
    }, function() {
        $("#mewlyDiagnosed").animate({'height': '162px', 'top': "0px"});
    });
MISSING!

You never closed the outer $(function() {.

Correct way to load a Nib for a UIView subclass

MyViewClass *myViewObject = [[[NSBundle mainBundle] loadNibNamed:@"MyViewClassNib" owner:self options:nil] objectAtIndex:0]

I'm using this to initialise the reusable custom views I have.


Note that you can use "firstObject" at the end there, it's a little cleaner. "firstObject" is a handy method for NSArray and NSMutableArray.

Here's a typical example, of loading a xib to use as a table header. In your file YourClass.m

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
    return [[NSBundle mainBundle] loadNibNamed:@"TopArea" owner:self options:nil].firstObject;
}

Normally, in the TopArea.xib, you would click on File Owner and set the file owner to YourClass. Then actually in YourClass.h you would have IBOutlet properties. In TopArea.xib, you can drag controls to those outlets.

Don't forget that in TopArea.xib, you may have to click on the View itself and drag that to some outlet, so you have control of it, if necessary. (A very worthwhile tip is that when you are doing this for table cell rows, you absolutely have to do that - you have to connect the view itself to the relevant property in your code.)

Use the auto keyword in C++ STL

This is new item in the language which I think we are going to be struggling with for years to come. The 'auto' of the start presents not only readability problem , from now on when you encounter it you will have to spend considerable time trying to figure out wtf it is(just like the time that intern named all variables xyz :)), but you also will spend considerable time cleaning after easily excitable programmers , like the once who replied before me. Example from above , I can bet $1000 , will be written "for (auto it : s)", not "for (auto& it : s)", as a result invoking move semantics where you list expecting it, modifying your collection underneath .

Another example of the problem is your question itself. You clearly don't know much about stl iterators and you trying to overcome that gap through usage of the magic of 'auto', as a result you create the code that might be problematic later on

In a Dockerfile, How to update PATH environment variable?

You can use Environment Replacement in your Dockerfile as follows:

ENV PATH="/opt/gtk/bin:${PATH}"

Measuring function execution time in R

As Andrie said, system.time() works fine. For short function I prefer to put replicate() in it:

system.time( replicate(10000, myfunction(with,arguments) ) )

c# regex matches example

This pattern should work:

#\d

foreach(var match in System.Text.RegularExpressions.RegEx.Matches(input, "#\d"))
{
    Console.WriteLine(match.Value);
}

(I'm not in front of Visual Studio, but even if that doesn't compile as-is, it should be close enough to tweak into something that works).

Detect Click into Iframe using JavaScript

You can achieve this by using the blur event on window element.

Here is a jQuery plugin for tracking click on iframes (it will fire a custom callback function when an iframe is clicked) : https://github.com/finalclap/iframeTracker-jquery

Use it like this :

jQuery(document).ready(function($){
    $('.iframe_wrap iframe').iframeTracker({
        blurCallback: function(){
            // Do something when iframe is clicked (like firing an XHR request)
        }
    });
});

How do I remove accents from characters in a PHP string?

What about the WordPress implementation?

function remove_accents($string) {
    if ( !preg_match('/[\x80-\xff]/', $string) )
        return $string;

    $chars = array(
    // Decompositions for Latin-1 Supplement
    chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
    chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
    chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
    chr(195).chr(135) => 'C', chr(195).chr(136) => 'E',
    chr(195).chr(137) => 'E', chr(195).chr(138) => 'E',
    chr(195).chr(139) => 'E', chr(195).chr(140) => 'I',
    chr(195).chr(141) => 'I', chr(195).chr(142) => 'I',
    chr(195).chr(143) => 'I', chr(195).chr(145) => 'N',
    chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
    chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
    chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
    chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
    chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
    chr(195).chr(159) => 's', chr(195).chr(160) => 'a',
    chr(195).chr(161) => 'a', chr(195).chr(162) => 'a',
    chr(195).chr(163) => 'a', chr(195).chr(164) => 'a',
    chr(195).chr(165) => 'a', chr(195).chr(167) => 'c',
    chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
    chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
    chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
    chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
    chr(195).chr(177) => 'n', chr(195).chr(178) => 'o',
    chr(195).chr(179) => 'o', chr(195).chr(180) => 'o',
    chr(195).chr(181) => 'o', chr(195).chr(182) => 'o',
    chr(195).chr(182) => 'o', chr(195).chr(185) => 'u',
    chr(195).chr(186) => 'u', chr(195).chr(187) => 'u',
    chr(195).chr(188) => 'u', chr(195).chr(189) => 'y',
    chr(195).chr(191) => 'y',
    // Decompositions for Latin Extended-A
    chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
    chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
    chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
    chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
    chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
    chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
    chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
    chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
    chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
    chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
    chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
    chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
    chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
    chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
    chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
    chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
    chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
    chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
    chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
    chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
    chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
    chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
    chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
    chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
    chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
    chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
    chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
    chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
    chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
    chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
    chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
    chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
    chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
    chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
    chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
    chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
    chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
    chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
    chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
    chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
    chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
    chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
    chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
    chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
    chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
    chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
    chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
    chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
    chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
    chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
    chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
    chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
    chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
    chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
    chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
    chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
    chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
    chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
    chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
    chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
    chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
    chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
    chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
    chr(197).chr(190) => 'z', chr(197).chr(191) => 's'
    );

    $string = strtr($string, $chars);

    return $string;
}

To understand what this function does, check the conversion table:

À => A
Á => A
 => A
à => A
Ä => A
Å => A
Ç => C
È => E
É => E
Ê => E
Ë => E
Ì => I
Í => I
Î => I
Ï => I
Ñ => N
Ò => O
Ó => O
Ô => O
Õ => O
Ö => O
Ù => U
Ú => U
Û => U
Ü => U
Ý => Y
ß => s
à => a
á => a
â => a
ã => a
ä => a
å => a
ç => c
è => e
é => e
ê => e
ë => e
ì => i
í => i
î => i
ï => i
ñ => n
ò => o
ó => o
ô => o
õ => o
ö => o
ù => u
ú => u
û => u
ü => u
ý => y
ÿ => y
A => A
a => a
A => A
a => a
A => A
a => a
C => C
c => c
C => C
c => c
C => C
c => c
C => C
c => c
D => D
d => d
Ð => D
d => d
E => E
e => e
E => E
e => e
E => E
e => e
E => E
e => e
E => E
e => e
G => G
g => g
G => G
g => g
G => G
g => g
G => G
g => g
H => H
h => h
H => H
h => h
I => I
i => i
I => I
i => i
I => I
i => i
I => I
i => i
I => I
i => i
? => IJ
? => ij
J => J
j => j
K => K
k => k
? => k
L => L
l => l
L => L
l => l
L => L
l => l
? => L
? => l
L => L
l => l
N => N
n => n
N => N
n => n
N => N
n => n
? => N
? => n
? => N
O => O
o => o
O => O
o => o
O => O
o => o
Π=> OE
œ => oe
R => R
r => r
R => R
r => r
R => R
r => r
S => S
s => s
S => S
s => s
S => S
s => s
Š => S
š => s
T => T
t => t
T => T
t => t
T => T
t => t
U => U
u => u
U => U
u => u
U => U
u => u
U => U
u => u
U => U
u => u
U => U
u => u
W => W
w => w
Y => Y
y => y
Ÿ => Y
Z => Z
z => z
Z => Z
z => z
Ž => Z
ž => z
? => s

You can generate the conversion table yourself by simply iterating over the $chars array of the function:

foreach($chars as $k=>$v) {
   printf("%s -> %s", $k, $v);
}

Does Ruby have a string.startswith("abc") built in method?

You can use String =~ Regex. It returns position of full regex match in string.

irb> ("abc" =~ %r"abc") == 0
=> true
irb> ("aabc" =~ %r"abc") == 0
=> false

Shortcut key for commenting out lines of Python code in Spyder

Yes, there is a shortcut for commenting out lines in Python 3.6 (Spyder).

For Single Line Comment, you can use Ctrl+1. It will look like this #This is a sample piece of code

For multi-line comments, you can use Ctrl+4. It will look like this

#============= \#your piece of code \#some more code \#=============

Note : \ represents that the code is carried to another line.

Post parameter is always null

If you have this character '\' in your json query in Postman, you should escape it if you need the character '\' in the json string value.

Example:

{
    "path": "C:\\Users\\Test\\Documents\\test.txt"
}

WPF Application that only has a tray icon

You have to use the NotifyIcon control from System.Windows.Forms, or alternatively you can use the Notify Icon API provided by Windows API. WPF Provides no such equivalent, and it has been requested on Microsoft Connect several times.

I have code on GitHub which uses System.Windows.Forms NotifyIcon Component from within a WPF application, the code can be viewed at https://github.com/wilson0x4d/Mubox/blob/master/Mubox.QuickLaunch/AppWindow.xaml.cs

Here are the summary bits:

Create a WPF Window with ShowInTaskbar=False, and which is loaded in a non-Visible State.

At class-level:

private System.Windows.Forms.NotifyIcon notifyIcon = null;

During OnInitialize():

notifyIcon = new System.Windows.Forms.NotifyIcon();
notifyIcon.Click += new EventHandler(notifyIcon_Click);
notifyIcon.DoubleClick += new EventHandler(notifyIcon_DoubleClick);
notifyIcon.Icon = IconHandles["QuickLaunch"];

During OnLoaded():

notifyIcon.Visible = true;

And for interaction (shown as notifyIcon.Click and DoubleClick above):

void notifyIcon_Click(object sender, EventArgs e)
{
    ShowQuickLaunchMenu();
}

From here you can resume the use of WPF Controls and APIs such as context menus, pop-up windows, etc.

It's that simple. You don't exactly need a WPF Window to host to the component, it's just the most convenient way to introduce one into a WPF App (as a Window is generally the default entry point defined via App.xaml), likewise, you don't need a WPF Wrapper or 3rd party control, as the SWF component is guaranteed present in any .NET Framework installation which also has WPF support since it's part of the .NET Framework (which all current and future .NET Framework versions build upon.) To date, there is no indication from Microsoft that SWF support will be dropped from the .NET Framework anytime soon.

Hope that helps.

It's a little cheese that you have to use a pre-3.0 Framework Component to get a tray-icon, but understandably as Microsoft has explained it, there is no concept of a System Tray within the scope of WPF. WPF is a presentation technology, and Notification Icons are an Operating System (not a "Presentation") concept.

How to draw in JPanel? (Swing/graphics Java)

Here is a simple example. I suppose it will be easy to understand:

import java.awt.*;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Graph extends JFrame {
JFrame f = new JFrame();
JPanel jp;


public Graph() {
    f.setTitle("Simple Drawing");
    f.setSize(300, 300);
    f.setDefaultCloseOperation(EXIT_ON_CLOSE);

    jp = new GPanel();
    f.add(jp);
    f.setVisible(true);
}

public static void main(String[] args) {
    Graph g1 = new Graph();
    g1.setVisible(true);
}

class GPanel extends JPanel {
    public GPanel() {
        f.setPreferredSize(new Dimension(300, 300));
    }

    @Override
    public void paintComponent(Graphics g) {
        //rectangle originates at 10,10 and ends at 240,240
        g.drawRect(10, 10, 240, 240);
        //filled Rectangle with rounded corners.    
        g.fillRoundRect(50, 50, 100, 100, 80, 80);
    }
}

}

And the output looks like this:

Output

Importing CSV data using PHP/MySQL

i think the main things to remember about parsing csv is that it follows some simple rules:

a)it's a text file so easily opened b) each row is determined by a line end \n so split the string into lines first c) each row/line has columns determined by a comma so split each line by that to get an array of columns

have a read of this post to see what i am talking about

it's actually very easy to do once you have the hang of it and becomes very useful.

Maven Jacoco Configuration - Exclude classes/packages from report not working

https://github.com/jacoco/jacoco/issues/34

These are the different notations for classes we have:

  • VM Name: java/util/Map$Entry
  • Java Name: java.util.Map$Entry File
  • Name: java/util/Map$Entry.class

Agent Parameters, Ant tasks and Maven prepare-agent goal

  • includes: Java Name (VM Name also works)
  • excludes: Java Name (VM Name also works)
  • exclclassloader: Java Name

These specifications allow wildcards * and ?, where * wildcards any number of characters, even multiple nested folders.

Maven report goal

  • includes: File Name
  • excludes: File Name

These specs allow Ant Filespec like wildcards *, ** and ?, where * wildcards parts of a single path element only.

TypeError: 'float' object is not subscriptable

PriceList[0][1][2][3][4][5][6]

This says: go to the 1st item of my collection PriceList. That thing is a collection; get its 2nd item. That thing is a collection; get its 3rd...

Instead, you want slicing:

PriceList[:7] = [PizzaChange]*7

Parse json string to find and element (key / value)

Use a JSON parser, like JSON.NET

string json = "{ \"Atlantic/Canary\": \"GMT Standard Time\", \"Europe/Lisbon\": \"GMT Standard Time\", \"Antarctica/Mawson\": \"West Asia Standard Time\", \"Etc/GMT+3\": \"SA Eastern Standard Time\", \"Etc/GMT+2\": \"UTC-02\", \"Etc/GMT+1\": \"Cape Verde Standard Time\", \"Etc/GMT+7\": \"US Mountain Standard Time\", \"Etc/GMT+6\": \"Central America Standard Time\", \"Etc/GMT+5\": \"SA Pacific Standard Time\", \"Etc/GMT+4\": \"SA Western Standard Time\", \"Pacific/Wallis\": \"UTC+12\", \"Europe/Skopje\": \"Central European Standard Time\", \"America/Coral_Harbour\": \"SA Pacific Standard Time\", \"Asia/Dhaka\": \"Bangladesh Standard Time\", \"America/St_Lucia\": \"SA Western Standard Time\", \"Asia/Kashgar\": \"China Standard Time\", \"America/Phoenix\": \"US Mountain Standard Time\", \"Asia/Kuwait\": \"Arab Standard Time\" }";
var data = (JObject)JsonConvert.DeserializeObject(json);
string timeZone = data["Atlantic/Canary"].Value<string>();

Running EXE with parameters

System.Diagnostics.Process.Start("PATH to exe", "Command Line Arguments");

Use CASE statement to check if column exists in table - SQL Server

Try this one -

SELECT *
FROM ...
WHERE EXISTS(SELECT 1 
        FROM sys.columns c
        WHERE c.[object_id] = OBJECT_ID('dbo.Tags')
            AND c.name = 'ModifiedByUser'
    )

Difference between java HH:mm and hh:mm on SimpleDateFormat

h/H = 12/24 hours means you will write hh:mm = 12 hours format and HH:mm = 24 hours format

How do you hide the Address bar in Google Chrome for Chrome Apps?

Uncheck Always Show Toolbar in Full Screen in View menu:

enter image description here

and go to fullscreen then:

Alt+Cmd+F - on Mac

F11 - on Windows

'import' and 'export' may only appear at the top level

'import' and 'export' may only appear at the top level

This means that webpack is bundling the non-transpiled ES6 code, which is why these import/export statements are being found. babel-loader must therefore not be transpiling what you expect.

If you simply remove the include and exclude rules from its loader config, the default behavior of transpiling everything besides what's in node_modules will kick in. For some reason or another, the current rules are causing some/all files to be skipped.

module.exports = {
  entry: './src/entry.js',
  output: {
    filename: './public/js/app.js'
  },
  devtool: 'source-map',
  plugins: [
    new ExtractTextPlugin('./public/css/style.css')
  ],
  module: {
    preLoaders: [{
      test: /\.js$/, 
      exclude: /node_modules/,
      loader: 'jshint-loader'
    }],
    loaders: [{
      test: /\.scss$/,
      loader: ExtractTextPlugin.extract(
        'style',
        'css!sass'
      ),
    },
    {
      test: /\.vue$/,
      loader: 'vue'
    },
    {
      test: /\.js$/,
      loader: 'babel-loader',
      query: {
        presets: ['es2015']
      }
    }]
  }
};

CodeIgniter: Create new helper?

To retrieve an item from your config file, use the following function:

$this->config->item('item name'); Where item name is the $config array index you want to retrieve. For example, to fetch your language choice you'll do this:

$lang = $this->config->item('language'); The function returns FALSE (boolean) if the item you are trying to fetch does not exist.

If you are using the second parameter of the $this->config->load function in order to assign your config items to a specific index you can retrieve it by specifying the index name in the second parameter of the $this->config->item() function. Example:

// Loads a config file named blog_settings.php and assigns it to an index named "blog_settings"

$this->config->load('blog_settings', TRUE);

// Retrieve a config item named site_name contained within the blog_settings array

$site_name = $this->config->item('site_name', 'blog_settings');

// An alternate way to specify the same item:

$blog_config = $this->config->item('blog_settings');

$site_name = $blog_config['site_name'];

allowing only alphabets in text box using java script

You can try:

 function onlyAlphabets(e, t) {
        return (e.charCode > 64 && e.charCode < 91) || (e.charCode > 96 && e.charCode < 123) || e.charCode == 32;   
    }

what is the use of xsi:schemaLocation?

The Java XML parser that spring uses will read the schemaLocation values and try to load them from the internet, in order to validate the XML file. Spring, in turn, intercepts those load requests and serves up versions from inside its own JAR files.

If you omit the schemaLocation, then the XML parser won't know where to get the schema in order to validate the config.

How to pass in a react component into another react component to transclude the first component's content?

Note I provided a more in-depth answer here

Runtime wrapper:

It's the most idiomatic way.

const Wrapper = ({children}) => (
  <div>
    <div>header</div>
    <div>{children}</div>
    <div>footer</div>
  </div>
);

const App = () => <div>Hello</div>;

const WrappedApp = () => (
  <Wrapper>
    <App/>
  </Wrapper>
);

Note that children is a "special prop" in React, and the example above is syntactic sugar and is (almost) equivalent to <Wrapper children={<App/>}/>


Initialization wrapper / HOC

You can use an Higher Order Component (HOC). They have been added to the official doc recently.

// Signature may look fancy but it's just 
// a function that takes a component and returns a new component
const wrapHOC = (WrappedComponent) => (props) => (
  <div>
    <div>header</div>
    <div><WrappedComponent {...props}/></div>
    <div>footer</div>
  </div>
)

const App = () => <div>Hello</div>;

const WrappedApp = wrapHOC(App);

This can lead to (little) better performances because the wrapper component can short-circuit the rendering one step ahead with shouldComponentUpdate, while in the case of a runtime wrapper, the children prop is likely to always be a different ReactElement and cause re-renders even if your components extend PureComponent.

Notice that connect of Redux used to be a runtime wrapper but was changed to an HOC because it permits to avoid useless re-renders if you use the pure option (which is true by default)

You should never call an HOC during the render phase because creating React components can be expensive. You should rather call these wrappers at initialization.


Note that when using functional components like above, the HOC version do not provide any useful optimisation because stateless functional components do not implement shouldComponentUpdate

More explanations here: https://stackoverflow.com/a/31564812/82609

Convert string to integer type in Go?

If you control the input data, you can use the mini version

package main

import (
    "testing"
    "strconv"
)

func Atoi (s string) int {
    var (
        n uint64
        i int
        v byte
    )   
    for ; i < len(s); i++ {
        d := s[i]
        if '0' <= d && d <= '9' {
            v = d - '0'
        } else if 'a' <= d && d <= 'z' {
            v = d - 'a' + 10
        } else if 'A' <= d && d <= 'Z' {
            v = d - 'A' + 10
        } else {
            n = 0; break        
        }
        n *= uint64(10) 
        n += uint64(v)
    }
    return int(n)
}

func BenchmarkAtoi(b *testing.B) {
    for i := 0; i < b.N; i++ {
        in := Atoi("9999")
        _ = in
    }   
}

func BenchmarkStrconvAtoi(b *testing.B) {
    for i := 0; i < b.N; i++ {
        in, _ := strconv.Atoi("9999")
        _ = in
    }   
}

the fastest option (write your check if necessary). Result :

Path>go test -bench=. atoi_test.go
goos: windows
goarch: amd64
BenchmarkAtoi-2                 100000000               14.6 ns/op
BenchmarkStrconvAtoi-2          30000000                51.2 ns/op
PASS
ok      path     3.293s

How to round a Double to the nearest Int in swift?

Swift 3

var myNum = 8.09
myNum.rounded() // result = 8 and leaves myNum unmodified

Sum a list of numbers in Python

Try the following -

mylist = [1, 2, 3, 4]   

def add(mylist):
    total = 0
    for i in mylist:
        total += i
    return total

result = add(mylist)
print("sum = ", result)

How to get a string between two characters?

The "generic" way of doing this is to parse the string from the start, throwing away all the characters before the first bracket, recording the characters after the first bracket, and throwing away the characters after the second bracket.

I'm sure there's a regex library or something to do it though.

Use latest version of Internet Explorer in the webbrowser control

just adding the following to your html does the trick no need for registry settigns

<meta http-equiv="X-UA-Compatible" content="IE=11" >

How to pick a new color for each plotted line within a figure in matplotlib?

I don't know if you can automatically change the color, but you could exploit your loop to generate different colors:

for i in range(20):
   ax1.plot(x, y, color = (0, i / 20.0, 0, 1)

In this case, colors will vary from black to 100% green, but you can tune it if you want.

See the matplotlib plot() docs and look for the color keyword argument.

If you want to feed a list of colors, just make sure that you have a list big enough and then use the index of the loop to select the color

colors = ['r', 'b', ...., 'w']

for i in range(20):
   ax1.plot(x, y, color = colors[i])

Delete commit on gitlab

  1. git reset --hard CommitId
  2. git push -f origin master

1st command will rest your head to commitid and 2nd command will delete all commit after that commit id on master branch.

Note: Don't forget to add -f in push otherwise it will be rejected.

How to remove the left part of a string?

without having a to write a function, this will split according to list, in this case 'Mr.|Dr.|Mrs.', select everything after split with [1], then split again and grab whatever element. In the case below, 'Morris' is returned.

re.split('Mr.|Dr.|Mrs.', 'Mr. Morgan Morris')[1].split()[1]

Is there a way to add a gif to a Markdown file?

in addition to all answers above:

if you want to use a gif for your github repository README.md and don't want to address it from your root directory, it's not enough if you just copy the url of your browser, for example your browser URL is sth like:

https://github.com/ashkan-nasirzadeh/simpleShell/blob/master/README%20assets/shell-gif.gif

but you should open your gif in your github account and right click on it and click copy image address or sth like that which is sth like this:

https://github.com/ashkan-nasirzadeh/simpleShell/blob/master/README%20assets/shell-gif.gif?raw=true

How to execute multiple SQL statements from java

I'm not sure that you want to send two SELECT statements in one request statement because you may not be able to access both ResultSets. The database may only return the last result set.

Multiple ResultSets

However, if you're calling a stored procedure that you know can return multiple resultsets something like this will work

CallableStatement stmt = con.prepareCall(...);
try {
...

boolean results = stmt.execute();

while (results) {
    ResultSet rs = stmt.getResultSet();
    try {
    while (rs.next()) {
        // read the data
    }
    } finally {
        try { rs.close(); } catch (Throwable ignore) {}
    }

    // are there anymore result sets?
    results = stmt.getMoreResults();
}
} finally {
    try { stmt.close(); } catch (Throwable ignore) {}
}

Multiple SQL Statements

If you're talking about multiple SQL statements and only one SELECT then your database should be able to support the one String of SQL. For example I have used something like this on Sybase

StringBuffer sql = new StringBuffer( "SET rowcount 100" );
sql.append( " SELECT * FROM tbl_books ..." );
sql.append( " SET rowcount 0" );

stmt = conn.prepareStatement( sql.toString() );

This will depend on the syntax supported by your database. In this example note the addtional spaces padding the statements so that there is white space between the staments.

Python spacing and aligning strings

You should be able to use the format method:

"Location: {0:20} Revision {1}".format(Location,Revision)

You will have to figure out the of the format length for each line depending on the length of the label. The User line will need a wider format width than the Location or District lines.

How to Determine the Screen Height and Width in Flutter

You can use:

  • double width = MediaQuery.of(context).size.width;
  • double height = MediaQuery.of(context).size.height;

To get height just of SafeArea (for iOS 11 and above):

  • var padding = MediaQuery.of(context).padding;
  • double newheight = height - padding.top - padding.bottom;

How to allow only numbers in textbox in mvc4 razor

Hi try the following....

<div class="editor-field">
  <%: Html.TextBoxFor(m => m.UserName, new {onkeydown="return ValidateNumber(event);" })%>
  <%: Html.ValidationMessageFor(m => m.UserName) %>
</div>

SCRIPT

<script type="text/javascript">
   function ValidateNumber(e) {
       var evt = (e) ? e : window.event;
       var charCode = (evt.keyCode) ? evt.keyCode : evt.which;
       if (charCode > 31 && (charCode < 48 || charCode > 57)) {
           return false;
       }
       return true;
   };

Pandas groupby: How to get a union of strings

You may be able to use the aggregate (or agg) function to concatenate the values. (Untested code)

df.groupby('A')['B'].agg(lambda col: ''.join(col))

"Too many values to unpack" Exception

Most likely there is an error somewhere in the get_profile() call. In your view, before you return the request object, put this line:

request.user.get_profile()

It should raise the error, and give you a more detailed traceback, which you can then use to further debug.

fatal error C1010 - "stdafx.h" in Visual Studio how can this be corrected?

The first line of every source file of your project must be the following:

#include <stdafx.h>

Visit here to understand Precompiled Headers

What is the difference between loose coupling and tight coupling in the object oriented paradigm?

Tight coupling is when a group of classes are highly dependent on one another.

This scenario arises when a class assumes too many responsibilities, or when one concern is spread over many classes rather than having its own class.

Loose coupling is achieved by means of a design that promotes single-responsibility and separation of concerns.

A loosely-coupled class can be consumed and tested independently of other (concrete) classes.

Interfaces are a powerful tool to use for decoupling. Classes can communicate through interfaces rather than other concrete classes, and any class can be on the other end of that communication simply by implementing the interface.

Example of tight coupling:

class CustomerRepository
{
    private readonly Database database;

    public CustomerRepository(Database database)
    {
        this.database = database;
    }

    public void Add(string CustomerName)
    {
        database.AddRow("Customer", CustomerName);
    }
}

class Database
{
    public void AddRow(string Table, string Value)
    {
    }
}

Example of loose coupling:

class CustomerRepository
{
    private readonly IDatabase database;

    public CustomerRepository(IDatabase database)
    {
        this.database = database;
    }

    public void Add(string CustomerName)
    {
        database.AddRow("Customer", CustomerName);
    }
}

interface IDatabase
{
    void AddRow(string Table, string Value);
}

class Database implements IDatabase
{
    public void AddRow(string Table, string Value)
    {
    }
}

Another example here.

Python: instance has no attribute

Your class doesn't have a __init__(), so by the time it's instantiated, the attribute atoms is not present. You'd have to do C.setdata('something') so C.atoms becomes available.

>>> C = Residues()
>>> C.atoms.append('thing')

Traceback (most recent call last):
  File "<pyshell#84>", line 1, in <module>
    B.atoms.append('thing')
AttributeError: Residues instance has no attribute 'atoms'

>>> C.setdata('something')
>>> C.atoms.append('thing')   # now it works
>>> 

Unlike in languages like Java, where you know at compile time what attributes/member variables an object will have, in Python you can dynamically add attributes at runtime. This also implies instances of the same class can have different attributes.

To ensure you'll always have (unless you mess with it down the line, then it's your own fault) an atoms list you could add a constructor:

def __init__(self):
    self.atoms = []

Difference between ref and out parameters in .NET

out parameters are initialized by the method called, ref parameters are initialized before calling the method. Therefore, out parameters are used when you just need to get a secondary return value, ref parameters are used to get a value and potentially return a change to that value (secondarily to the main return value).

CakePHP find method with JOIN

Otro example, custom Data Pagination for JOIN

CODE in Controller CakePHP 2.6 is OK:

$this->SenasaPedidosFacturadosSds->recursive = -1;
    // Filtro
    $where = array(
        'joins' => array(
            array(
                'table' => 'usuarios',
                'alias' => 'Usuarios',
                'type' => 'INNER',
                'conditions' => array(
                    'Usuarios.usuario_id = SenasaPedidosFacturadosSds.usuarios_id'
                )
            ),
            array(
                'table' => 'senasa_pedidos',
                'alias' => 'SenasaPedidos',
                'type' => 'INNER',
                'conditions' => array(
                    'SenasaPedidos.id = SenasaPedidosFacturadosSds.senasa_pedidos_id'
                )
            ),
            array(
                'table' => 'clientes',
                'alias' => 'Clientes',
                'type' => 'INNER',
                'conditions' => array(
                    'Clientes.id_cliente = SenasaPedidos.clientes_id'
                )
            ),
        ),
        'fields'=>array(
            'SenasaPedidosFacturadosSds.*',
            'Usuarios.usuario_id',
            'Usuarios.apellido_nombre',
            'Usuarios.senasa_establecimientos_id',
            'Clientes.id_cliente',
            'Clientes.consolida_doc_sanitaria',
            'Clientes.requiere_senasa',
            'Clientes.razon_social',
            'SenasaPedidos.id',
            'SenasaPedidos.domicilio_entrega',
            'SenasaPedidos.sds',
            'SenasaPedidos.pt_ptr'
        ),
        'conditions'=>array(
            'Clientes.requiere_senasa'=>1
        ),
        'order' => 'SenasaPedidosFacturadosSds.created DESC',
        'limit'=>100
    );
    $this->paginate = $where;
    // Get datos
    $data = $this->Paginator->paginate();
    exit(debug($data));

OR Example 2, NOT active conditions:

$this->SenasaPedidosFacturadosSds->recursive = -1;
    // Filtro
    $where = array(
        'joins' => array(
            array(
                'table' => 'usuarios',
                'alias' => 'Usuarios',
                'type' => 'INNER',
                'conditions' => array(
                    'Usuarios.usuario_id = SenasaPedidosFacturadosSds.usuarios_id'
                )
            ),
            array(
                'table' => 'senasa_pedidos',
                'alias' => 'SenasaPedidos',
                'type' => 'INNER',
                'conditions' => array(
                    'SenasaPedidos.id = SenasaPedidosFacturadosSds.senasa_pedidos_id'
                )
            ),
            array(
                'table' => 'clientes',
                'alias' => 'Clientes',
                'type' => 'INNER',
                'conditions' => array(
                    'Clientes.id_cliente = SenasaPedidos.clientes_id',
                    'Clientes.requiere_senasa = 1'
                )
            ),
        ),
        'fields'=>array(
            'SenasaPedidosFacturadosSds.*',
            'Usuarios.usuario_id',
            'Usuarios.apellido_nombre',
            'Usuarios.senasa_establecimientos_id',
            'Clientes.id_cliente',
            'Clientes.consolida_doc_sanitaria',
            'Clientes.requiere_senasa',
            'Clientes.razon_social',
            'SenasaPedidos.id',
            'SenasaPedidos.domicilio_entrega',
            'SenasaPedidos.sds',
            'SenasaPedidos.pt_ptr'
        ),
        //'conditions'=>array(
        //    'Clientes.requiere_senasa'=>1
        //),
        'order' => 'SenasaPedidosFacturadosSds.created DESC',
        'limit'=>100
    );
    $this->paginate = $where;
    // Get datos
    $data = $this->Paginator->paginate();
    exit(debug($data));