Programs & Examples On #Property editor

SQL Server PRINT SELECT (Print a select query result)?

If you wish (like me) to have results containing mulitple rows of various SELECT queries "labelled" and can't manage this within the constraints of the PRINT statement in concert with the Messages tab you could turn it around and simply add messages to the Results tab per the below:

SELECT 'Results from scenario 1'
SELECT
    *
FROM tblSample

enter image description here

Assignment makes pointer from integer without cast

You are returning char, and not char*, which is the pointer to the first character of an array.

If you want to return a new character array instead of doing in-place modification, you can ask for an already allocated pointer (char*) as parameter or an uninitialized pointer. In this last case you must allocate the proper number of characters for new string and remember that in C parameters as passed by value ALWAYS, so you must use char** as parameter in the case of array allocated internally by function. Of course, the caller must free that pointer later.

how to change attribute "hidden" in jquery

$(':checkbox').change(function(){
    $('#delete').removeAttr('hidden');
});

Note, thanks to tip by A.Wolff, you should use removeAttr instead of setting to false. When set to false, the element will still be hidden. Therefore, removing is more effective.

How to force reloading a page when using browser back button?

Currently this is the most up to date way reload page if the user clicks the back button.

const [entry] = performance.getEntriesByType("navigation");

// Show it in a nice table in the developer console
console.table(entry.toJSON());

if (entry["type"] === "back_forward")
    location.reload();

See here for source

Simplest way to download and unzip files in Node.js cross-platform?

It's 2017 (October 26th, to be exact).

For an ancient and pervasive technology such as unzip I would expect there to exist a fairly popular, mature node.js unzip library that is "stagnant" and "unmaintained" because it is "complete".

However, most libraries appear either to be completely terrible or to have commits recently as just a few months ago. This is quite concerning... so I've gone through several unzip libraries, read their docs, and tried their examples to try to figure out WTF. For example, I've tried these:

Update 2020: Haven't tried it yet, but there's also archiver

Top Recommendation: yauzl

Works great for completely downloaded file. Not as great for streaming.

Well documented. Works well. Makes sense.

2nd Pick: node-stream-zip

antelle's node-stream-zip seems to be the best

Install:

npm install --save node-stream-zip

Usage:

'use strict';

var fs = require('fs');
var StreamZip = require('node-stream-zip');

var zip = new StreamZip({
  file: './example.zip'
, storeEntries: true
});

zip.on('error', function (err) { console.error('[ERROR]', err); });

zip.on('ready', function () {
  console.log('All entries read: ' + zip.entriesCount);
  //console.log(zip.entries());
});

zip.on('entry', function (entry) {
  var pathname = path.resolve('./temp', entry.name);
  if (/\.\./.test(path.relative('./temp', pathname))) {
      console.warn("[zip warn]: ignoring maliciously crafted paths in zip file:", entry.name);
      return;
  }

  if ('/' === entry.name[entry.name.length - 1]) {
    console.log('[DIR]', entry.name);
    return;
  }

  console.log('[FILE]', entry.name);
  zip.stream(entry.name, function (err, stream) {
    if (err) { console.error('Error:', err.toString()); return; }

    stream.on('error', function (err) { console.log('[ERROR]', err); return; });

    // example: print contents to screen
    //stream.pipe(process.stdout);

    // example: save contents to file
    fs.mkdir(
      path.dirname(pathname),
      { recursive: true },
      function (err) {
        stream.pipe(fs.createWriteStream(pathname));
      }
    );
  });
});

Security Warning:

Not sure if this checks entry.name for maliciously crafted paths that would resolve incorrectly (such as ../../../foo or /etc/passwd).

You can easily check this yourself by comparing /\.\./.test(path.relative('./to/dir', path.resolve('./to/dir', entry.name))).

Pros: (Why do I think it's the best?)

  • can unzip normal files (maybe not some crazy ones with weird extensions)
  • can stream
  • seems to not have to load the whole zip to read entries
  • has examples in normal JavaScript (not compiled)
  • doesn't include the kitchen sink (i.e. url loading, S3, or db layers)
  • uses some existing code from a popular library
  • doesn't have too much senseless hipster or ninja-foo in the code

Cons:

  • Swallows errors like a hungry hippo
  • Throws strings instead of errors (no stack traces)
  • zip.extract() doesn't seem to work (hence I used zip.stream() in my example)

Runner up: node-unzipper

Install:

npm install --save unzipper

Usage:

'use strict';

var fs = require('fs');
var unzipper = require('unzipper');

fs.createReadStream('./example.zip')
  .pipe(unzipper.Parse())
  .on('entry', function (entry) {
    var fileName = entry.path;
    var type = entry.type; // 'Directory' or 'File'

    console.log();
    if (/\/$/.test(fileName)) {
      console.log('[DIR]', fileName, type);
      return;
    }

    console.log('[FILE]', fileName, type);

    // TODO: probably also needs the security check

    entry.pipe(process.stdout/*fs.createWriteStream('output/path')*/);
    // NOTE: To ignore use entry.autodrain() instead of entry.pipe()
  });

Pros:

  • Seems to work in a similar manner to node-stream-zip, but less control
  • A more functional fork of unzip
  • Seems to run in serial rather than in parallel

Cons:

  • Kitchen sink much? Just includes a ton of stuff that's not related to unzipping
  • Reads the whole file (by chunk, which is fine), not just random seeks

rebase in progress. Cannot commit. How to proceed or stop (abort)?

I setup my git to autorebase on a git checkout

# in my ~/.gitconfig file
[branch]
    autosetupmerge = always
    autosetuprebase = always

Otherwise, it automatically merges when you switch between branches, which I think is the worst possible choice as the default.

However, this has a side effect, when I switch to a branch and then git cherry-pick <commit-id> I end up in this weird state every single time it has a conflict.

I actually have to abort the rebase, but first I fix the conflict, git add /path/to/file the file (another very strange way to resolve the conflict in this case?!), then do a git commit -i /path/to/file. Now I can abort the rebase:

git checkout <other-branch>
git cherry-pick <commit-id>
...edit-conflict(s)...
git add path/to/file
git commit -i path/to/file
git rebase --abort
git commit .
git push --force origin <other-branch>

The second git commit . seems to come from the abort. I'll fix my answer if I find out that I should abort the rebase sooner.

The --force on the push is required if you skip other commits and both branches are not smooth (both are missing commits from the other).

Why is json_encode adding backslashes?

Can anyone tell me why json_encode adds slashes?

Forward slash characters can cause issues (when preceded by a < it triggers the SGML rules for "end of script element") when embedded in an HTML script element. They are escaped as a precaution.

Because when I try do use jQuery.parseJSON(response); in my js script, it returns null. So my guess it has something to do with the slashes.

It doesn't. In JSON "/" and "\/" are equivalent.

The JSON you list in the question is valid (you can test it with jsonlint). Your problem is likely to do with what happens to it between json_encode and parseJSON.

Commenting out a set of lines in a shell script

Text editors have an amazing feature called search and replace. You don't say what editor you use, but since shell scripts tend to be *nix, and I use VI, here's the command to comment lines 20 to 50 of some shell script:

:20,50s/^/#/

Implement Validation for WPF TextBoxes

You can additionally implement IDataErrorInfo as follows in the view model. If you implement IDataErrorInfo, you can do the validation in that instead of the setter of a particular property, then whenever there is a error, return an error message so that the text box which has the error gets a red box around it, indicating an error.

class ViewModel : INotifyPropertyChanged, IDataErrorInfo
{
    private string m_Name = "Type Here";
    public ViewModel()
    {
    }

    public string Name
    {
        get
        {
            return m_Name;
        }
        set
        {
            if (m_Name != value)
            {
                m_Name = value;
                OnPropertyChanged("Name");
            }
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public string Error
    {
        get { return "...."; }
    }

    /// <summary>
    /// Will be called for each and every property when ever its value is changed
    /// </summary>
    /// <param name="columnName">Name of the property whose value is changed</param>
    /// <returns></returns>
    public string this[string columnName]
    {
        get 
        {
            return Validate(columnName);
        }
    }

    private string Validate(string propertyName)
    {
        // Return error message if there is error on else return empty or null string
        string validationMessage = string.Empty;
        switch (propertyName)
        {
            case "Name": // property name
                // TODO: Check validiation condition
                validationMessage = "Error";
                break;
        }

        return validationMessage;
    }
}

And you have to set ValidatesOnDataErrors=True in the XAML in order to invoke the methods of IDataErrorInfo as follows:

<TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" />

Find records with a date field in the last 24 hours

You simply select dates that are higher than the current time minus 1 day.

SELECT * FROM news WHERE date >= now() - INTERVAL 1 DAY;

Android Studio: Application Installation Failed

This problem cause to me because of the project path . Y:\Example&SourceCode with & sign So i change the Project path to another one without special characters. Now It is Fine.

React - uncaught TypeError: Cannot read property 'setState' of undefined

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>Hello World</title>

    <script src="https://unpkg.com/[email protected]/dist/react.min.js"></script>
    <script src="https://unpkg.com/[email protected]/dist/react-dom.min.js"></script>
    <script src="https://unpkg.com/[email protected]/babel.min.js"></script>

  </head>
  <body>
  <div id="root"></div>
    <script type="text/babel">

        class App extends React.Component{

            constructor(props){
                super(props);
                this.state = {
                    counter : 0,
                    isToggle: false
                }
            this.onEventHandler = this.onEventHandler.bind(this);   
            }

            increment = ()=>{
                this.setState({counter:this.state.counter + 1});
            }

            decrement= ()=>{
                if(this.state.counter > 0 ){
                this.setState({counter:this.state.counter - 1});    
                }else{
                this.setState({counter:0});             
                }
            }
            // Either do it as onEventHandler = () => {} with binding with this  // object. 
            onEventHandler(){
                this.setState({isToggle:!this.state.isToggle})
                alert('Hello');
            }


            render(){
                return(
                    <div>
                        <button onClick={this.increment}> Increment </button>
                        <button onClick={this.decrement}> Decrement </button>
                        {this.state.counter}
                        <button onClick={this.onEventHandler}> {this.state.isToggle ? 'Hi':'Ajay'} </button>

                    </div>
                    )
            }
        }
        ReactDOM.render(
        <App/>,
        document.getElementById('root'),
      );
    </script>
  </body>
  </html>

Handling key-press events (F1-F12) using JavaScript and jQuery, cross-browser

You can do this with jquery like this:

        $("#elemenId").keydown(function (e) {
            if(e.key == "F12"){
                console.log(e.key);
            }

        });

Asynchronously wait for Task<T> to complete with timeout

You can use Task.WaitAny to wait the first of multiple tasks.

You could create two additional tasks (that complete after the specified timeouts) and then use WaitAny to wait for whichever completes first. If the task that completed first is your "work" task, then you're done. If the task that completed first is a timeout task, then you can react to the timeout (e.g. request cancellation).

SQL Server : export query as a .txt file

This is quite simple to do and the answer is available in other queries. For those of you who are viewing this:

select entries from my_entries where id='42' INTO OUTFILE 'bishwas.txt';

How to get row from R data.frame

10 years later ---> Using tidyverse we could achieve this simply and borrowing a leaf from Christopher Bottoms. For a better grasp, see slice().

library(tidyverse)
x <- structure(list(A = c(5,    3.5, 3.25, 4.25,  1.5 ), 
                    B = c(4.25, 4,   4,    4.5,   4.5 ),
                    C = c(4.5,  2.5, 4,    2.25,  3   )
),
.Names    = c("A", "B", "C"),
class     = "data.frame",
row.names = c(NA, -5L)
)

x
#>      A    B    C
#> 1 5.00 4.25 4.50
#> 2 3.50 4.00 2.50
#> 3 3.25 4.00 4.00
#> 4 4.25 4.50 2.25
#> 5 1.50 4.50 3.00

y<-c(A=5, B=4.25, C=4.5)
y
#>    A    B    C 
#> 5.00 4.25 4.50

#The slice() verb allows one to subset data row-wise. 
x <- x %>% slice(1) #(n) for the nth row, or (i:n) for range i to n, (i:n()) for i to last row...

x
#>   A    B   C
#> 1 5 4.25 4.5

#Test that the items in the row match the vector you wanted
x[1,]==y
#>      A    B    C
#> 1 TRUE TRUE TRUE

Created on 2020-08-06 by the reprex package (v0.3.0)

How do I list loaded plugins in Vim?

The problem with :scriptnames, :commands, :functions, and similar Vim commands, is that they display information in a large slab of text, which is very hard to visually parse.

To get around this, I wrote Headlights, a plugin that adds a menu to Vim showing all loaded plugins, TextMate style. The added benefit is that it shows plugin commands, mappings, files, and other bits and pieces.

Color theme for VS Code integrated terminal

In case you are color picky, use this code to customize every segment.

Step 1: Windows: Open user settings (ctrl + ,) Mac: Command + Shift + P

Step 2: Search for "workbench: color customizations" and select Edit in settings.json. Page the following code inside existing {} and customize as you like.

"workbench.colorCustomizations": {
    "terminal.background":"#131212",
    "terminal.foreground":"#dddad6",
    "terminal.ansiBlack":"#1D2021",
    "terminal.ansiBrightBlack":"#665C54",
    "terminal.ansiBrightBlue":"#0D6678",
    "terminal.ansiBrightCyan":"#8BA59B",
    "terminal.ansiBrightGreen":"#237e02",
    "terminal.ansiBrightMagenta":"#8F4673",
    "terminal.ansiBrightRed":"#FB543F",
    "terminal.ansiBrightWhite":"#FDF4C1",
    "terminal.ansiBrightYellow":"#FAC03B",
    "terminal.ansiCyan":"#8BA59B",
    "terminal.ansiGreen":"#95C085",
    "terminal.ansiMagenta":"#8F4673",
    "terminal.ansiRed":"#FB543F",
    "terminal.ansiWhite":"#A89984",
    "terminal.ansiYellow":"#FAC03B"
  }

How display only years in input Bootstrap Datepicker?

format: "YYYY" 

Should be capital instead of "yyyy"

Excel how to find values in 1 column exist in the range of values in another

This is what you need:

 =NOT(ISERROR(MATCH(<cell in col A>,<column B>, 0)))  ## pseudo code

For the first cell of A, this would be:

 =NOT(ISERROR(MATCH(A2,$B$2:$B$5, 0)))

Enter formula (and drag down) as follows:

enter image description here

You will get:

enter image description here

How to convert a byte array to Stream

In your case:

MemoryStream ms = new MemoryStream(buffer);

What is let-* in Angular 2 templates?

The Angular microsyntax lets you configure a directive in a compact, friendly string. The microsyntax parser translates that string into attributes on the <ng-template>. The let keyword declares a template input variable that you reference within the template.

Why shouldn't I use mysql_* functions in PHP?

First, let's begin with the standard comment we give everyone:

Please, don't use mysql_* functions in new code. They are no longer maintained and are officially deprecated. See the red box? Learn about prepared statements instead, and use PDO or MySQLi - this article will help you decide which. If you choose PDO, here is a good tutorial.

Let's go through this, sentence by sentence, and explain:

  • They are no longer maintained, and are officially deprecated

    This means that the PHP community is gradually dropping support for these very old functions. They are likely to not exist in a future (recent) version of PHP! Continued use of these functions may break your code in the (not so) far future.

    NEW! - ext/mysql is now officially deprecated as of PHP 5.5!

    Newer! ext/mysql has been removed in PHP 7.

  • Instead, you should learn of prepared statements

    mysql_* extension does not support prepared statements, which is (among other things) a very effective countermeasure against SQL Injection. It fixed a very serious vulnerability in MySQL dependent applications which allows attackers to gain access to your script and perform any possible query on your database.

    For more information, see How can I prevent SQL injection in PHP?

  • See the Red Box?

    When you go to any mysql function manual page, you see a red box, explaining it should not be used anymore.

  • Use either PDO or MySQLi

    There are better, more robust and well-built alternatives, PDO - PHP Database Object, which offers a complete OOP approach to database interaction, and MySQLi, which is a MySQL specific improvement.

Custom Python list sorting

It's documented here.

The sort() method takes optional arguments for controlling the comparisons.

cmp specifies a custom comparison function of two arguments (list items) which should return a negative, zero or positive number depending on whether the first argument is considered smaller than, equal to, or larger than the second argument: cmp=lambda x,y: cmp(x.lower(), y.lower()). The default value is None.

SQL Server: Null VS Empty String

The conceptual differences between NULL and "empty-string" are real and very important in database design, but often misunderstood and improperly applied - here's a short description of the two:

NULL - means that we do NOT know what the value is, it may exist, but it may not exist, we just don't know.

Empty-String - means we know what the value is and that it is nothing.

Here's a simple example: Suppose you have a table with people's names including separate columns for first_name, middle_name, and last_name. In the scenario where first_name = 'John', last_name = 'Doe', and middle_name IS NULL, it means that we do not know what the middle name is, or if it even exists. Change that scenario such that middle_name = '' (i.e. empty-string), and it now means that we know that there is no middle name.

I once heard a SQL Server instructor promote making every character type column in a database required, and then assigning a DEFAULT VALUE to each of either '' (empty-string), or 'unknown'. In stating this, the instructor demonstrated he did not have a clear understanding of the difference between NULLs and empty-strings. Admittedly, the differences can seem confusing, but for me the above example helps to clarify the difference. Also, it is important to understand the difference when writing SQL code, and properly handle for NULLs as well as empty-strings.

Keyboard shortcuts with jQuery

There is a new version of hotKeys.js that works with 1.10+ version of jQuery. It is small, 100 line javascript file. 4kb or just 2kb minified. Here are some Simple usage examples are :

$('#myBody').hotKey({ key: 'c', modifier: 'alt' }, doSomething);

$('#myBody').hotKey({ key: 'f4' }, doSomethingElse);

$('#myBody').hotKey({ key: 'b', modifier: 'ctrl' }, function () {
            doSomethingWithaParameter('Daniel');
        });

$('#myBody').hotKey({ key: 'd', modifier :'shift' }, doSomethingCool);

Clone the repo from github : https://github.com/realdanielbyrne/HoyKeys.git or go to the github repo page https://github.com/realdanielbyrne/HoyKeys or fork and contribute.

How to execute a command in a remote computer?

IMO, in your case you can try this:

  1. Map the shared folder to a drive or folder on your machine. (here's how)
  2. Access the mapped drive/folder as you normally would local files.

Nothing needs to be installed. No services need to be running except those that enable folder sharing.

If you can access the shared folder and maps it on your machine, most things should work just like local files, including command prompts and all explorer-enhancement tools.

This is different from using PsExec (or RDP-ing in) in that you do not need to have administrative rights and/or remote desktop/terminal services connection rights on the remote server, you just need to be able to access those shared folders.

Also make sure you have all the necessary security permissions to run whatever commands/tools you want to run on those shared folders as well.


If, however you wish the processing to be done on the target machine, then you can try PsExec as @divo and @recursive pointed out, something alongs:

PsExec \\yourServerName -u yourUserName cmd.exe

Which will brings gives you a command prompt at the remote machine. And from there you can execute whatever you want.

I am not sure but I think you need either the Server (lanmanserver) or the Terminal Services (TermService) service to be running (which should have already be running).

How do I create a round cornered UILabel on the iPhone?

Depending on what exactly you are doing you could make an image and set it as the background programatically.

How to select the first element in the dropdown using jquery?

Here is a simple javascript solution which works in most cases:

document.getElementById("selectId").selectedIndex = "0";

Move cursor to end of file in vim

If you want to paste some clipboard content at the end of the file type:

:$ put +

$ ............ last line
put .......... paste 
+ ............ clipboard

Clear text in EditText when entered

i don't know what mistakes i did while implementing the above solutions, bt they were unsuccessful for me

txtDeck.setOnFocusChangeListener(new OnFocusChangeListener() {
    @Override       
    public void onFocusChange(View v, boolean hasFocus) {
        txtDeck.setText("");
    }
});

This works for me,

How to embed matplotlib in pyqt - for Dummies

Below is an adaptation of previous code for using under PyQt5 and Matplotlib 2.0. There are a number of small changes: structure of PyQt submodules, other submodule from matplotlib, deprecated method has been replaced...


import sys
from PyQt5.QtWidgets import QDialog, QApplication, QPushButton, QVBoxLayout

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt

import random

class Window(QDialog):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)

        # a figure instance to plot on
        self.figure = plt.figure()

        # this is the Canvas Widget that displays the `figure`
        # it takes the `figure` instance as a parameter to __init__
        self.canvas = FigureCanvas(self.figure)

        # this is the Navigation widget
        # it takes the Canvas widget and a parent
        self.toolbar = NavigationToolbar(self.canvas, self)

        # Just some button connected to `plot` method
        self.button = QPushButton('Plot')
        self.button.clicked.connect(self.plot)

        # set the layout
        layout = QVBoxLayout()
        layout.addWidget(self.toolbar)
        layout.addWidget(self.canvas)
        layout.addWidget(self.button)
        self.setLayout(layout)

    def plot(self):
        ''' plot some random stuff '''
        # random data
        data = [random.random() for i in range(10)]

        # instead of ax.hold(False)
        self.figure.clear()

        # create an axis
        ax = self.figure.add_subplot(111)

        # discards the old graph
        # ax.hold(False) # deprecated, see above

        # plot data
        ax.plot(data, '*-')

        # refresh canvas
        self.canvas.draw()

if __name__ == '__main__':
    app = QApplication(sys.argv)

    main = Window()
    main.show()

    sys.exit(app.exec_())

What is the most elegant way to check if all values in a boolean array are true?

You can check all value items are true or false by compare your array with the other boolean array via Arrays.equal method like below example :

private boolean isCheckedAnswer(List<Answer> array) {
    boolean[] isSelectedChecks = new boolean[array.size()];
    for (int i = 0; i < array.size(); i++) {
        isSelectedChecks[i] = array.get(i).isChecked();
    }

    boolean[] isAllFalse = new boolean[array.size()];
    for (int i = 0; i < array.size(); i++) {
        isAllFalse[i] = false;
    }

    return !Arrays.equals(isSelectedChecks, isAllFalse);
}

How to create enum like type in TypeScript?

Update:

As noted by @iX3, Typescript 2.4 has support for enum strings.

See:Create an enum with string values in Typescript


Original answer:

For String member values, TypeScript only allows numbers as enum member values. But there are a few solutions/hacks you can implement;

Solution 1:

copied from: https://blog.rsuter.com/how-to-implement-an-enum-with-string-values-in-typescript/

There is a simple solution: Just cast the string literal to any before assigning:

export enum Language {
    English = <any>"English",
    German = <any>"German",
    French = <any>"French",
    Italian = <any>"Italian"
}

solution 2:

copied from: https://basarat.gitbooks.io/typescript/content/docs/types/literal-types.html

You can use a string literal as a type. For example:

let foo: 'Hello';

Here we have created a variable called foo that will only allow the literal value 'Hello' to be assigned to it. This is demonstrated below:

let foo: 'Hello';
foo = 'Bar'; // Error: "Bar" is not assignable to type "Hello"

They are not very useful on their own but can be combined in a type union to create a powerful (and useful) abstraction e.g.:

type CardinalDirection =
    "North"
    | "East"
    | "South"
    | "West";

function move(distance: number, direction: CardinalDirection) {
    // ...
}

move(1,"North"); // Okay
move(1,"Nurth"); // Error!

How do I Set Background image in Flutter?

decoration: BoxDecoration(
      image: DecorationImage(
        image: ExactAssetImage("images/background.png"),
        fit: BoxFit.cover
      ),
    ),

this also works inside a container.

How to create a notification with NotificationCompat.Builder?

Notification in depth

CODE

Intent intent = new Intent(this, SecondActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this,0,intent,0);

NotificationCompat.Builder mBuilder =
                new NotificationCompat.Builder(context)
                        .setSmallIcon(R.drawable.your_notification_icon)
                        .setContentTitle("Notification Title")
                        .setContentText("Notification ")
                        .setContentIntent(pendingIntent );

NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(0, mBuilder.build());

Depth knowledge

Notification can be build using Notification. Builder or NotificationCompat.Builder classes.
But if you want backward compatibility you should use NotificationCompat.Builder class as it is part of v4 Support library as it takes care of heavy lifting for providing consistent look and functionalities of Notification for API 4 and above.

Core Notification Properties

A notification has 4 core properties (3 Basic display properties + 1 click action property)

  • Small icon
  • Title
  • Text
  • Button click event (Click event when you tap the notification )

Button click event is made optional on Android 3.0 and above. It means that you can build your notification using only display properties if your minSdk targets Android 3.0 or above. But if you want your notification to run on older devices than Android 3.0 then you must provide Click event otherwise you will see IllegalArgumentException.

Notification Display

Notification are displayed by calling notify() method of NotificationManger class

notify() parameters

There are two variants available for notify method

notify(String tag, int id, Notification notification)

or

notify(int id, Notification notification)

notify method takes an integer id to uniquely identify your notification. However, you can also provide an optional String tag for further identification of your notification in case of conflict.

This type of conflict is rare but say, you have created some library and other developers are using your library. Now they create their own notification and somehow your notification and other dev's notification id is same then you will face conflict.

Notification after API 11 (More control)

API 11 provides additional control on Notification behavior

  • Notification Dismissal
    By default, if a user taps on notification then it performs the assigned click event but it does not clear away the notification. If you want your notification to get cleared when then you should add this

    mBuilder.setAutoClear(true);

  • Prevent user from dismissing notification
    A user may also dismiss the notification by swiping it. You can disable this default behavior by adding this while building your notification

    mBuilder.setOngoing(true);

  • Positioning of notification
    You can set the relative priority to your notification by

    mBuilder.setOngoing(int pri);

If your app runs on lower API than 11 then your notification will work without above mentioned additional features. This is the advantage to choosing NotificationCompat.Builder over Notification.Builder

Notification after API 16 (More informative)

With the introduction of API 16, notifications were given so many new features
Notification can be so much more informative.
You can add a bigPicture to your logo. Say you get a message from a person now with the mBuilder.setLargeIcon(Bitmap bitmap) you can show that person's photo. So in the statusbar you will see the icon when you scroll you will see the person photo in place of the icon. There are other features too

  • Add a counter in the notification
  • Ticker message when you see the notification for the first time
  • Expandable notification
  • Multiline notification and so on

What is the closest thing Windows has to fork()?

There is no easy way to emulate fork() on Windows.

I suggest you to use threads instead.

How to add images to README.md on GitHub?

You can just do:

git checkout --orphan assets
cp /where/image/currently/located/on/machine/diagram.png .
git add .
git commit -m 'Added diagram'
git push -u origin assets

Then you can just reference it in the README file like so:

![diagram](diagram.png)

Foreign Key Django Model

You create the relationships the other way around; add foreign keys to the Person type to create a Many-to-One relationship:

class Person(models.Model):
    name = models.CharField(max_length=50)
    birthday = models.DateField()
    anniversary = models.ForeignKey(
        Anniversary, on_delete=models.CASCADE)
    address = models.ForeignKey(
        Address, on_delete=models.CASCADE)

class Address(models.Model):
    line1 = models.CharField(max_length=150)
    line2 = models.CharField(max_length=150)
    postalcode = models.CharField(max_length=10)
    city = models.CharField(max_length=150)
    country = models.CharField(max_length=150)

class Anniversary(models.Model):
    date = models.DateField()

Any one person can only be connected to one address and one anniversary, but addresses and anniversaries can be referenced from multiple Person entries.

Anniversary and Address objects will be given a reverse, backwards relationship too; by default it'll be called person_set but you can configure a different name if you need to. See Following relationships "backward" in the queries documentation.

Selenium WebDriver and DropDown Boxes

Just wrap your WebElement into Select Object as shown below

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

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

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

Now to identify dropdown do

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

To select its option say 'Programmer' you can do

dropdown.selectByVisibleText("Programmer ");

or

 dropdown.selectByIndex(1);

or

 dropdown.selectByValue("prog");

Happy Coding :)

Escape text for HTML

Also, you can use this if you don't want to use the System.Web assembly:

var encoded = System.Security.SecurityElement.Escape(unencoded)

Per this article, the difference between System.Security.SecurityElement.Escape() and System.Web.HttpUtility.HtmlEncode() is that the former also encodes apostrophe (') characters.

How to evaluate a boolean variable in an if block in bash?

bash doesn't know boolean variables, nor does test (which is what gets called when you use [).

A solution would be:

if $myVar ; then ... ; fi

because true and false are commands that return 0 or 1 respectively which is what if expects.

Note that the values are "swapped". The command after if must return 0 on success while 0 means "false" in most programming languages.

SECURITY WARNING: This works because BASH expands the variable, then tries to execute the result as a command! Make sure the variable can't contain malicious code like rm -rf /

What's the best way to loop through a set of elements in JavaScript?

I too advise to use the simple way (KISS !-)

-- but some optimization could be found, namely not to test the length of an array more than once:

var elements = document.getElementsByTagName('div');
for (var i=0, im=elements.length; im>i; i++) {
    doSomething(elements[i]);
}

How do you test running time of VBA code?

Seconds with 2 decimal spaces:

Dim startTime As Single 'start timer
MsgBox ("run time: " & Format((Timer - startTime) / 1000000, "#,##0.00") & " seconds") 'end timer

seconds format

Milliseconds:

Dim startTime As Single 'start timer
MsgBox ("run time: " & Format((Timer - startTime), "#,##0.00") & " milliseconds") 'end timer

milliseconds format

Milliseconds with comma seperator:

Dim startTime As Single 'start timer
MsgBox ("run time: " & Format((Timer - startTime) * 1000, "#,##0.00") & " milliseconds") 'end timer

Milliseconds with comma seperator

Just leaving this here for anyone that was looking for a simple timer formatted with seconds to 2 decimal spaces like I was. These are short and sweet little timers I like to use. They only take up one line of code at the beginning of the sub or function and one line of code again at the end. These aren't meant to be crazy accurate, I generally don't care about anything less then 1/100th of a second personally, but the milliseconds timer will give you the most accurate run time of these 3. I've also read you can get the incorrect read out if it happens to run while crossing over midnight, a rare instance but just FYI.

Arithmetic overflow error converting numeric to data type numeric

Use TRY_CAST function in exact same way of CAST function. TRY_CAST takes a string and tries to cast it to a data type specified after the AS keyword. If the conversion fails, TRY_CAST returns a NULL instead of failing.

replace NULL with Blank value or Zero in sql server

The coalesce() is the best solution when there are multiple columns [and]/[or] values and you want the first one. However, looking at books on-line, the query optimize converts it to a case statement.

MSDN excerpt

The COALESCE expression is a syntactic shortcut for the CASE expression.

That is, the code COALESCE(expression1,...n) is rewritten by the query optimizer as the following CASE expression:

CASE
   WHEN (expression1 IS NOT NULL) THEN expression1
   WHEN (expression2 IS NOT NULL) THEN expression2
   ...
   ELSE expressionN
END

With that said, why not a simple ISNULL()? Less code = better solution?

Here is a complete code snippet.

-- drop the test table
drop table #temp1
go

-- create test table
create table #temp1
(
    issue varchar(100) NOT NULL,
    total_amount int NULL
); 
go

-- create test data
insert into #temp1 values
    ('No nulls here', 12),
    ('I am a null', NULL);
go

-- isnull works fine
select
    isnull(total_amount, 0) as total_amount  
from #temp1

Last but not least, how are you getting null values into a NOT NULL column?

I had to change the table definition so that I could setup the test case. When I try to alter the table to NOT NULL, it fails since it does a nullability check.

-- this alter fails
alter table #temp1 alter column total_amount int NOT NULL

How do I obtain crash-data from my Android application?

Just Started to use ACRA https://github.com/ACRA/acra using Google Forms as backend and it's very easy to setup & use, it's the default.

BUT Sending reports to Google Forms are going to be deprecated (then removed): https://plus.google.com/118444843928759726538/posts/GTTgsrEQdN6 https://github.com/ACRA/acra/wiki/Notice-on-Google-Form-Spreadsheet-usage

Anyway it's possible to define your own sender https://github.com/ACRA/acra/wiki/AdvancedUsage#wiki-Implementing_your_own_sender you can give a try to email sender for example.

With minimum effort it's possible to send reports to bugsense: http://www.bugsense.com/docs/android#acra

NB The bugsense free account is limited to 500 report/month

How do I filter query objects by date range in Django?

You can use django's filter with datetime.date objects:

import datetime
samples = Sample.objects.filter(sampledate__gte=datetime.date(2011, 1, 1),
                                sampledate__lte=datetime.date(2011, 1, 31))

Return string without trailing slash

ES6 / ES2015 provides an API for asking whether a string ends with something, which enables writing a cleaner and more readable function.

const stripTrailingSlash = (str) => {
    return str.endsWith('/') ?
        str.slice(0, -1) :
        str;
};

Rails 4 - Strong Parameters - Nested Objects

I found this suggestion useful in my case:

  def product_params
    params.require(:product).permit(:name).tap do |whitelisted|
      whitelisted[:data] = params[:product][:data]
    end
  end

Check this link of Xavier's comment on github.

This approach whitelists the entire params[:measurement][:groundtruth] object.

Using the original questions attributes:

  def product_params
    params.require(:measurement).permit(:name, :groundtruth).tap do |whitelisted|
      whitelisted[:groundtruth] = params[:measurement][:groundtruth]
    end
  end

jquery how to get the page's current screen top position?

Use this to get the page scroll position.

var screenTop = $(document).scrollTop();

$('#content').css('top', screenTop);

Stacked Tabs in Bootstrap 3

To get left and right tabs (now also with sideways) support for Bootstrap 3, bootstrap-vertical-tabs component can be used.

https://github.com/dbtek/bootstrap-vertical-tabs

Single quotes vs. double quotes in Python

I like to use double quotes around strings that are used for interpolation or that are natural language messages, and single quotes for small symbol-like strings, but will break the rules if the strings contain quotes, or if I forget. I use triple double quotes for docstrings and raw string literals for regular expressions even if they aren't needed.

For example:

LIGHT_MESSAGES = {
    'English': "There are %(number_of_lights)s lights.",
    'Pirate':  "Arr! Thar be %(number_of_lights)s lights."
}

def lights_message(language, number_of_lights):
    """Return a language-appropriate string reporting the light count."""
    return LIGHT_MESSAGES[language] % locals()

def is_pirate(message):
    """Return True if the given message sounds piratical."""
    return re.search(r"(?i)(arr|avast|yohoho)!", message) is not None

How do I tell if .NET 3.5 SP1 is installed?

Check is the following directory exists:

In 64bit machines: %SYSTEMROOT%\Microsoft.NET\Framework64\v3.5\Microsoft .NET Framework 3.5 SP1\

In 32bit machines: %SYSTEMROOT%\Microsoft.NET\Framework\v3.5\Microsoft .NET Framework 3.5 SP1\

Where %SYSTEMROOT% is the SYSTEMROOT enviromental variable (e.g. C:\Windows).

How to prevent form from submitting multiple times from client side?

The simpliest and elegant solution for me:

function checkForm(form) // Submit button clicked
{
    form.myButton.disabled = true;
    form.myButton.value = "Please wait...";
    return true;
}

<form method="POST" action="..." onsubmit="return checkForm(this);">
    ...
    <input type="submit" name="myButton" value="Submit">
</form>

Link for more...

Left Join without duplicate rows from left table

You can do this using generic SQL with group by:

SELECT C.Content_ID, C.Content_Title, MAX(M.Media_Id)
FROM tbl_Contents C LEFT JOIN
     tbl_Media M
     ON M.Content_Id = C.Content_Id 
GROUP BY C.Content_ID, C.Content_Title
ORDER BY MAX(C.Content_DatePublished) ASC;

Or with a correlated subquery:

SELECT C.Content_ID, C.Contt_Title,
       (SELECT M.Media_Id
        FROM tbl_Media M
        WHERE M.Content_Id = C.Content_Id
        ORDER BY M.MEDIA_ID DESC
        LIMIT 1
       ) as Media_Id
FROM tbl_Contents C 
ORDER BY C.Content_DatePublished ASC;

Of course, the syntax for limit 1 varies between databases. Could be top. Or rownum = 1. Or fetch first 1 rows. Or something like that.

Java decimal formatting using String.format?

You want java.text.DecimalFormat.

DecimalFormat df = new DecimalFormat("0.00##");
String result = df.format(34.4959);

Run a batch file with Windows task scheduler

Make sure "Start In" does NOT end with a BACKSLASH.

PHP7 : install ext-dom issue

For CentOS, RHEL, Fedora:

$ yum search php-xml
============================================================================================================ N/S matched: php-xml ============================================================================================================
php-xml.x86_64 : A module for PHP applications which use XML
php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php-xmlseclibs.noarch : PHP library for XML Security
php54-php-xml.x86_64 : A module for PHP applications which use XML
php54-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php55-php-xml.x86_64 : A module for PHP applications which use XML
php55-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php56-php-xml.x86_64 : A module for PHP applications which use XML
php56-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php70-php-xml.x86_64 : A module for PHP applications which use XML
php70-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php71-php-xml.x86_64 : A module for PHP applications which use XML
php71-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php72-php-xml.x86_64 : A module for PHP applications which use XML
php72-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php73-php-xml.x86_64 : A module for PHP applications which use XML
php73-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol

Then select the php-xml version matching your php version:

# php -v
PHP 7.2.11 (cli) (built: Oct 10 2018 10:00:29) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies

# sudo yum install -y php72-php-xml.x86_64

Clear icon inside input text

jQuery Mobile now has this built in:

<input type="text" name="clear" id="clear-demo" value="" data-clear-btn="true">

Jquery Mobile API TextInput docs

SQL: how to select a single id ("row") that meets multiple criteria from a single column

First way: JOIN:

get people with multiple countries:

SELECT u1.user_id 
FROM users u1
JOIN users u2
on u1.user_id  = u2.user_id 
AND u1.ancestry <> u2.ancestry

Get people from 2 specific countries:

SELECT u1.user_id 
FROM users u1
JOIN users u2
on u1.user_id  = u2.user_id 
WHERE u1.ancestry = 'Germany'
AND u2.ancestry = 'France'

For 3 countries... join three times. To only get the result(s) once, distinct.

Second way: GROUP BY

This will get users which have 3 lines (having...count) and then you specify which lines are permitted. Note that if you don't have a UNIQUE KEY on (user_id, ancestry), a user with 'id, england' that appears 3 times will also match... so it depends on your table structure and/or data.

SELECT user_id 
FROM users u1
WHERE ancestry = 'Germany'
OR ancestry = 'France'
OR ancestry = 'England'
GROUP BY user_id
HAVING count(DISTINCT ancestry) = 3

Is there "\n" equivalent in VBscript?

For replace you can use vbCrLf:

Replace(string, vbCrLf, "")

You can also use chr(13)+chr(10).

I seem to remember in some odd cases that chr(10) comes before chr(13).

list.clear() vs list = new ArrayList<Integer>();

List.clear would remove the elements without reducing the capacity of the list.

groovy:000> mylist = [1,2,3,4,5,6,7,8,9,10,11,12]
===> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
groovy:000> mylist.elementData.length
===> 12
groovy:000> mylist.elementData
===> [Ljava.lang.Object;@19d6af
groovy:000> mylist.clear()
===> null
groovy:000> mylist.elementData.length
===> 12
groovy:000> mylist.elementData
===> [Ljava.lang.Object;@19d6af
groovy:000> mylist = new ArrayList();
===> []
groovy:000> mylist.elementData
===> [Ljava.lang.Object;@2bfdff
groovy:000> mylist.elementData.length
===> 10

Here mylist got cleared, the references to the elements held by it got nulled out, but it keeps the same backing array. Then mylist was reinitialized and got a new backing array, the old one got GCed. So one way holds onto memory, the other one throws out its memory and gets reallocated from scratch (with the default capacity). Which is better depends on whether you want to reduce garbage-collection churn or minimize the current amount of unused memory. Whether the list sticks around long enough to be moved out of Eden might be a factor in deciding which is faster (because that might make garbage-collecting it more expensive).

How to send email from MySQL 5.1

If you have an SMTP service running, you can outfile to the drop directory. If you have high volume, you may result with duplicate file names, but there are ways to avoid that.

Otherwise, you will need to create a UDF.

Here's a sample trigger solution:

CREATE TRIGGER test.autosendfromdrop BEFORE INSERT ON test.emaildrop
FOR EACH ROW BEGIN
      /* START THE WRITING OF THE EMAIL FILE HERE*/      
      SELECT  concat("To: ",NEW.To),
              concat("From: ",NEW.From),
              concat("Subject: ",NEW.Subject),
              NEW.Body
          INTO OUTFILE 
                   "C:\\inetpub\\mailroot\\pickup\\mail.txt" 
              FIELDS TERMINATED by '\r\n' ESCAPED BY '';            
END;

To markup the message body you will need something like this...

CREATE FUNCTION `HTMLBody`(Msg varchar(8192)) 
    RETURNS varchar(17408) CHARSET latin1 DETERMINISTIC
BEGIN
  declare tmpMsg varchar(17408);
  set tmpMsg = cast(concat(
      'Date: ',date_format(NOW(),'%e %b %Y %H:%i:%S -0600'),'\r\n',
      'MIME-Version: 1.0','\r\n',
      'Content-Type: multipart/alternative;','\r\n',
      ' boundary=\"----=_NextPart_000_0000_01CA4B3F.8C263EE0\"','\r\n',
      'Content-Class: urn:content-classes:message','\r\n',
      'Importance: normal','\r\n',
      'Priority: normal','\r\n','','\r\n','','\r\n',
      'This is a multi-part message in MIME format.','\r\n','','\r\n',
      '------=_NextPart_000_0000_01CA4B3F.8C263EE0','\r\n',
      'Content-Type: text/plain;','\r\n',
      '  charset=\"iso-8859-1\"','\r\n',
      'Content-Transfer-Encoding: 7bit','\r\n','','\r\n','','\r\n',
      Msg,
      '\r\n','','\r\n','','\r\n',
      '------=_NextPart_000_0000_01CA4B3F.8C263EE0','\r\n',
      'Content-Type: text/html','\r\n',
      'Content-Transfer-Encoding: 7bit','\r\n','','\r\n',
      Msg,
      '\r\n','------=_NextPart_000_0000_01CA4B3F.8C263EE0--'
      ) as char);
  RETURN tmpMsg;
END ;

How to prevent scrollbar from repositioning web page?

Wrap the content of your scrollable element into a div and apply padding-left: calc(100vw - 100%);.

<body>
    <div style="padding-left: calc(100vw - 100%);">
        Some Content that is higher than the user's screen
    </div>
</body>

The trick is that 100vw represents 100% of the viewport including the scrollbar. If you subtract 100%, which is the available space without the scrollbar, you end up with the width of the scrollbar or 0 if it is not present. Creating a padding of that width on the left will simulate a second scrollbar, shifting centered content back to the right.

Please note that this will only work if the scrollable element uses the page's entire width, but this should be no problem most of the time because there are only few other cases where you have centered scrollable content.

In Node.js, how do I "include" functions from my other files?

Another way to do this in my opinion, is to execute everything in the lib file when you call require() function using (function(/* things here */){})(); doing this will make all these functions global scope, exactly like the eval() solution

src/lib.js

(function () {
    funcOne = function() {
            console.log('mlt funcOne here');
    }

    funcThree = function(firstName) {
            console.log(firstName, 'calls funcThree here');
    }

    name = "Mulatinho";
    myobject = {
            title: 'Node.JS is cool',
            funcFour: function() {
                    return console.log('internal funcFour() called here');
            }
    }
})();

And then in your main code you can call your functions by name like:

main.js

require('./src/lib')
funcOne();
funcThree('Alex');
console.log(name);
console.log(myobject);
console.log(myobject.funcFour());

Will make this output

bash-3.2$ node -v
v7.2.1
bash-3.2$ node main.js 
mlt funcOne here
Alex calls funcThree here
Mulatinho
{ title: 'Node.JS is cool', funcFour: [Function: funcFour] }
internal funcFour() called here
undefined

Pay atention to the undefined when you call my object.funcFour(), it will be the same if you load with eval(). Hope it helps :)

Static Classes In Java

Java has static methods that are associated with classes (e.g. java.lang.Math has only static methods), but the class itself is not static.

CSS: stretching background image to 100% width and height of screen?

I would recommend background-size: cover; if you don't want your background to lose its proportions: JS Fiddle

html { 
  background: url(image/path) no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

Source: http://css-tricks.com/perfect-full-page-background-image/

Add custom headers to WebView resource requests - android

Here is an implementation using HttpUrlConnection:

class CustomWebviewClient : WebViewClient() {
    private val charsetPattern = Pattern.compile(".*?charset=(.*?)(;.*)?$")

    override fun shouldInterceptRequest(view: WebView, request: WebResourceRequest): WebResourceResponse? {
        try {
            val connection: HttpURLConnection = URL(request.url.toString()).openConnection() as HttpURLConnection
            connection.requestMethod = request.method
            for ((key, value) in request.requestHeaders) {
                connection.addRequestProperty(key, value)
            }

            connection.addRequestProperty("custom header key", "custom header value")

            var contentType: String? = connection.contentType
            var charset: String? = null
            if (contentType != null) {
                // some content types may include charset => strip; e. g. "application/json; charset=utf-8"
                val contentTypeTokenizer = StringTokenizer(contentType, ";")
                val tokenizedContentType = contentTypeTokenizer.nextToken()

                var capturedCharset: String? = connection.contentEncoding
                if (capturedCharset == null) {
                    val charsetMatcher = charsetPattern.matcher(contentType)
                    if (charsetMatcher.find() && charsetMatcher.groupCount() > 0) {
                        capturedCharset = charsetMatcher.group(1)
                    }
                }
                if (capturedCharset != null && !capturedCharset.isEmpty()) {
                    charset = capturedCharset
                }

                contentType = tokenizedContentType
            }

            val status = connection.responseCode
            var inputStream = if (status == HttpURLConnection.HTTP_OK) {
                connection.inputStream
            } else {
                // error stream can sometimes be null even if status is different from HTTP_OK
                // (e. g. in case of 404)
                connection.errorStream ?: connection.inputStream
            }
            val headers = connection.headerFields
            val contentEncodings = headers.get("Content-Encoding")
            if (contentEncodings != null) {
                for (header in contentEncodings) {
                    if (header.equals("gzip", true)) {
                        inputStream = GZIPInputStream(inputStream)
                        break
                    }
                }
            }
            return WebResourceResponse(contentType, charset, status, connection.responseMessage, convertConnectionResponseToSingleValueMap(connection.headerFields), inputStream)
        } catch (e: Exception) {
            e.printStackTrace()
        }
        return super.shouldInterceptRequest(view, request)
    }

    private fun convertConnectionResponseToSingleValueMap(headerFields: Map<String, List<String>>): Map<String, String> {
        val headers = HashMap<String, String>()
        for ((key, value) in headerFields) {
            when {
                value.size == 1 -> headers[key] = value[0]
                value.isEmpty() -> headers[key] = ""
                else -> {
                    val builder = StringBuilder(value[0])
                    val separator = "; "
                    for (i in 1 until value.size) {
                        builder.append(separator)
                        builder.append(value[i])
                    }
                    headers[key] = builder.toString()
                }
            }
        }
        return headers
    }
}

Note that this does not work for POST requests because WebResourceRequest doesn't provide POST data. There is a Request Data - WebViewClient library which uses a JavaScript injection workaround for intercepting POST data.

In Bootstrap 3,How to change the distance between rows in vertical?

UPDATE

Bootstrap 4 has spacing utilities to handle this https://getbootstrap.com/docs/4.0/utilities/spacing/

.mt-0 {
  margin-top: 0 !important;
}

--

ORIGINAL ANSWER

If you are using SASS, this is what I normally do.

$margins: (xs: 0.5rem, sm: 1rem, md: 1.5rem, lg: 2rem, xl: 2.5rem);

@each $name, $value in $margins {
  .margin-top-#{$name} {
    margin-top: $value;
  }

  .margin-bottom-#{$name} {
    margin-bottom: $value;
  }
}

so you can later use margin-top-xs for example

RESTful Authentication

Tips valid for securing any web application

If you want to secure your application, then you should definitely start by using HTTPS instead of HTTP, this ensures a creating secure channel between you & the users that will prevent sniffing the data sent back & forth to the users & will help keep the data exchanged confidential.

You can use JWTs (JSON Web Tokens) to secure RESTful APIs, this has many benefits when compared to the server-side sessions, the benefits are mainly:

1- More scalable, as your API servers will not have to maintain sessions for each user (which can be a big burden when you have many sessions)

2- JWTs are self contained & have the claims which define the user role for example & what he can access & issued at date & expiry date (after which JWT won't be valid)

3- Easier to handle across load-balancers & if you have multiple API servers as you won't have to share session data nor configure server to route the session to same server, whenever a request with a JWT hit any server it can be authenticated & authorized

4- Less pressure on your DB as well as you won't have to constantly store & retrieve session id & data for each request

5- The JWTs can't be tampered with if you use a strong key to sign the JWT, so you can trust the claims in the JWT that is sent with the request without having to check the user session & whether he is authorized or not, you can just check the JWT & then you are all set to know who & what this user can do.

Many libraries provide easy ways to create & validate JWTs in most programming languages, for example: in node.js one of the most popular is jsonwebtoken

Since REST APIs generally aims to keep the server stateless, so JWTs are more compatible with that concept as each request is sent with Authorization token that is self contained (JWT) without the server having to keep track of user session compared to sessions which make the server stateful so that it remembers the user & his role, however, sessions are also widely used & have their pros, which you can search for if you want.

One important thing to note is that you have to securely deliver the JWT to the client using HTTPS & save it in a secure place (for example in local storage).

You can learn more about JWTs from this link

Process.start: how to get the output?

You can log process output using below code:

ProcessStartInfo pinfo = new ProcessStartInfo(item);
pinfo.CreateNoWindow = false;
pinfo.UseShellExecute = true;
pinfo.RedirectStandardOutput = true;
pinfo.RedirectStandardInput = true;
pinfo.RedirectStandardError = true;
pinfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal;
var p = Process.Start(pinfo);
p.WaitForExit();
Process process = Process.Start(new ProcessStartInfo((item + '>' + item + ".txt"))
{
    UseShellExecute = false,
    RedirectStandardOutput = true
});
process.WaitForExit();
string output = process.StandardOutput.ReadToEnd();
if (process.ExitCode != 0) { 
}

Use CSS to remove the space between images

Make them display: block in your CSS.

'' is not recognized as an internal or external command, operable program or batch file

When you want to run an executable file from the Command prompt, (cmd.exe), or a batch file, it will:

  • Search the current working directory for the executable file.
  • Search all locations specified in the %PATH% environment variable for the executable file.

If the file isn't found in either of those options you will need to either:

  1. Specify the location of your executable.
  2. Change the working directory to that which holds the executable.
  3. Add the location to %PATH% by apending it, (recommended only with extreme caution).

You can see which locations are specified in %PATH% from the Command prompt, Echo %Path%.

Because of your reported error we can assume that Mobile.exe is not in the current directory or in a location specified within the %Path% variable, so you need to use 1., 2. or 3..

Examples for 1.

C:\directory_path_without_spaces\My-App\Mobile.exe

or:

"C:\directory path with spaces\My-App\Mobile.exe"

Alternatively you may try:

Start C:\directory_path_without_spaces\My-App\Mobile.exe

or

Start "" "C:\directory path with spaces\My-App\Mobile.exe"

Where "" is an empty title, (you can optionally add a string between those doublequotes).

Examples for 2.

CD /D C:\directory_path_without_spaces\My-App
Mobile.exe

or

CD /D "C:\directory path with spaces\My-App"
Mobile.exe

You could also use the /D option with Start to change the working directory for the executable to be run by the start command

Start /D C:\directory_path_without_spaces\My-App Mobile.exe

or

Start "" /D "C:\directory path with spaces\My-App" Mobile.exe

C# - Fill a combo box with a DataTable

string strConn = "Data Source=SEZSW08;Initial Catalog=Nidhi;Integrated Security=True";
SqlConnection Con = new SqlConnection(strConn);
Con.Open();
string strCmd = "select companyName from companyinfo where CompanyName='" + cmbCompName.SelectedValue + "';";
SqlDataAdapter da = new SqlDataAdapter(strCmd, Con);
DataSet ds = new DataSet();
Con.Close();
da.Fill(ds);
cmbCompName.DataSource = ds;
cmbCompName.DisplayMember = "CompanyName";
cmbCompName.ValueMember = "CompanyName";
//cmbCompName.DataBind();
cmbCompName.Enabled = true;

In C#, what's the difference between \n and \r\n?

\n is the line break used by Unix(-like) systems, \r\n is used by windows. This has nothing to do with C#.

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 programmatically set SelectedValue of Dropdownlist when it is bound to XmlDataSource

This seems to work for me.

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

MySQL - Selecting data from multiple tables all with same structure but different data

Any of the above answers are valid, or an alternative way is to expand the table name to include the database name as well - eg:

SELECT * from us_music, de_music where `us_music.genre` = 'punk' AND `de_music.genre` = 'punk'

How to define custom exception class in Java, the easiest way?

If you use the new class dialog in Eclipse you can just set the Superclass field to java.lang.Exception and check "Constructors from superclass" and it will generate the following:

package com.example.exception;

public class MyException extends Exception {

    public MyException() {
        // TODO Auto-generated constructor stub
    }

    public MyException(String message) {
        super(message);
        // TODO Auto-generated constructor stub
    }

    public MyException(Throwable cause) {
        super(cause);
        // TODO Auto-generated constructor stub
    }

    public MyException(String message, Throwable cause) {
        super(message, cause);
        // TODO Auto-generated constructor stub
    }

}

In response to the question below about not calling super() in the defualt constructor, Oracle has this to say:

Note: If a constructor does not explicitly invoke a superclass constructor, the Java compiler automatically inserts a call to the no-argument constructor of the superclass.

How do I use shell variables in an awk script?

I had to insert date at the beginning of the lines of a log file and it's done like below:

DATE=$(date +"%Y-%m-%d")
awk '{ print "'"$DATE"'", $0; }' /path_to_log_file/log_file.log

It can be redirect to another file to save

Remove end of line characters from Java string

public static void main(final String[] argv) 
{
    String str;

    str = "hello\r\n\tjava\r\nbook";
    str = str.replaceAll("(\\r|\\n|\\t)", "");
    System.out.println(str);
}

It would be useful to add the tabulation in regex too.

The project was not built since its build path is incomplete

Here is what made the error disappear for me:

Close eclipse, open up a terminal window and run:

$ mvn clean eclipse:clean eclipse:eclipse

Are you using Maven? If so,

  1. Right-click on the project, Build Path and go to Configure Build Path
  2. Click the libraries tab. If Maven dependencies are not in the list, you need to add it.
  3. Close the dialog.

To add it: Right-click on the project, Maven → Disable Maven Nature Right-click on the project, Configure → Convert to Maven Project.

And then clean

Edit 1:

If that doesn't resolve the issue try right-clicking on your project and select properties. Select Java Build Path → Library tab. Look for a JVM. If it's not there, click to add Library and add the default JVM. If VM is there, click edit and select the default JVM. Hopefully, that works.

Edit 2:

You can also try going into the folder where you have all your projects and delete the .metadata for eclipse (be aware that you'll have to re-import all the projects afterwards! Also all the environment settings you've set would also have to be redone). After it was deleted just import the project again, and hopefully, it works.

How can I split a delimited string into an array in PHP?

Code:

$string = "9,[email protected],8";

$array  = explode(",", $string);

print_r($array);

$no = 1;
foreach ($array as $line) {
    echo $no . ". " . $line . PHP_EOL;
    $no++;
};

Online:

_x000D_
_x000D_
body, html, iframe { _x000D_
  width: 100% ;_x000D_
  height: 100% ;_x000D_
  overflow: hidden ;_x000D_
}
_x000D_
<iframe src="https://ideone.com/pGEAlb" ></iframe>
_x000D_
_x000D_
_x000D_

Showing an image from an array of images - Javascript

This is a simple example and try to combine it with yours using some modifications. I prefer you set all the images in one array in order to make your code easier to read and shorter:

var myImage = document.getElementById("mainImage");

var imageArray = ["_images/image1.jpg","_images/image2.jpg","_images/image3.jpg",
  "_images/image4.jpg","_images/image5.jpg","_images/image6.jpg"];

var imageIndex = 0; 

function changeImage() {
  myImage.setAttribute("src",imageArray[imageIndex]);
  imageIndex = (imageIndex + 1) % imageArray.length;
}

setInterval(changeImage, 5000);

Changing the "tick frequency" on x or y axis in matplotlib?

Since None of the above solutions worked for my usecase, here I provide a solution using None (pun!) which can be adapted to a wide variety of scenarios.

Here is a sample piece of code that produces cluttered ticks on both X and Y axes.

# Note the super cluttered ticks on both X and Y axis.

# inputs
x = np.arange(1, 101)
y = x * np.log(x) 

fig = plt.figure()     # create figure
ax = fig.add_subplot(111)
ax.plot(x, y)
ax.set_xticks(x)        # set xtick values
ax.set_yticks(y)        # set ytick values

plt.show()

Now, we clean up the clutter with a new plot that shows only a sparse set of values on both x and y axes as ticks.

# inputs
x = np.arange(1, 101)
y = x * np.log(x)

fig = plt.figure()       # create figure
ax = fig.add_subplot(111)
ax.plot(x, y)

ax.set_xticks(x)
ax.set_yticks(y)

# which values need to be shown?
# here, we show every third value from `x` and `y`
show_every = 3

sparse_xticks = [None] * x.shape[0]
sparse_xticks[::show_every] = x[::show_every]

sparse_yticks = [None] * y.shape[0]
sparse_yticks[::show_every] = y[::show_every]

ax.set_xticklabels(sparse_xticks, fontsize=6)   # set sparse xtick values
ax.set_yticklabels(sparse_yticks, fontsize=6)   # set sparse ytick values

plt.show()

Depending on the usecase, one can adapt the above code simply by changing show_every and using that for sampling tick values for X or Y or both the axes.

If this stepsize based solution doesn't fit, then one can also populate the values of sparse_xticks or sparse_yticks at irregular intervals, if that is what is desired.

Fatal error compiling: invalid target release: 1.8 -> [Help 1]

In my case the maven "Run configuration" was using the wrong JRE (1.7). Be sure to check Run -> Run Configurations -> (Tab) JRE to be some jdk1.8.x.

How to check if variable is array?... or something array-like

Since PHP 7.1 there is a pseudo-type iterable for exactly this purpose. Type-hinting iterable accepts any array as well as any implementation of the Traversable interface. PHP 7.1 also introduced the function is_iterable(). For older versions, see other answers here for accomplishing the equivalent type enforcement without the newer built-in features.

Fair play: As BlackHole pointed out, this question appears to be a duplicate of Iterable objects and array type hinting? and his or her answer goes into further detail than mine.

How do I right align div elements?

You can use flexbox with flex-grow to push the last element to the right.

<div style="display: flex;">
  <div style="flex-grow: 1;">Left</div>
  <div>Right</div>
</div>

Using 'starts with' selector on individual class names

I'd recommend making "apple" its own class. You should avoid the starts-with/ends-with if you can because being able to select using div.apple would be a lot faster. That's the more elegant solution. Don't be afraid to split things out into separate classes if it makes the task simpler/faster.

How to fix getImageData() error The canvas has been tainted by cross-origin data?

You are "tainting" the canvas by loading from a cross origins domain. Check out this MDN article:

https://developer.mozilla.org/en-US/docs/HTML/CORS_Enabled_Image

How do you create a temporary table in an Oracle database?

CREATE GLOBAL TEMPORARY TABLE Table_name
    (startdate DATE,
     enddate DATE,
     class CHAR(20))
  ON COMMIT DELETE ROWS;

Combine two arrays

The new way of doing it with php7.4 is Spread operator [...]

$parts = ['apple', 'pear'];
$fruits = ['banana', 'orange', ...$parts, 'watermelon'];
var_dump($fruits);

Spread operator should have better performance than array_merge

A significant advantage of Spread operator is that it supports any traversable objects, while the array_merge function only supports arrays.

How to hide the soft keyboard from inside a fragment?

This code works for fragments:

getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

What is the difference between Integrated Security = True and Integrated Security = SSPI?

Many questions get answers if we use .Net Reflector to see the actual code of SqlConnection :) true and sspi are the same:

internal class DbConnectionOptions

...

internal bool ConvertValueToIntegratedSecurityInternal(string stringValue)
{
    if ((CompareInsensitiveInvariant(stringValue, "sspi") || CompareInsensitiveInvariant(stringValue, "true")) || CompareInsensitiveInvariant(stringValue, "yes"))
    {
        return true;
    }
}

...

EDIT 20.02.2018 Now in .Net Core we can see its open source on github! Search for ConvertValueToIntegratedSecurityInternal method:

https://github.com/dotnet/corefx/blob/fdbb160aeb0fad168b3603dbdd971d568151a0c8/src/System.Data.SqlClient/src/System/Data/Common/DbConnectionOptions.cs

Create array of regex matches

Java makes regex too complicated and it does not follow the perl-style. Take a look at MentaRegex to see how you can accomplish that in a single line of Java code:

String[] matches = match("aa11bb22", "/(\\d+)/g" ); // => ["11", "22"]

Are there best practices for (Java) package organization?

I prefer feature before layers, but I guess it depends on you project. Consider your forces:

  • Dependencies
    Try minimize package dependencies, especially between features. Extract APIs if necessary.
  • Team organization
    In some organizations teams work on features and in others on layers. This influence how code is organized, use it to formalize APIs or encourage cooperation.
  • Deployment and versioning
    Putting everything into a module make deployment and versioning simpler, but bug fixing harder. Splitting things enable better control, scalability and availability.
  • Respond to change
    Well organized code is much simpler to change than a big ball of mud.
  • Size (people and lines of code)
    The bigger the more formalized/standardized it needs to be.
  • Importance/quality
    Some code is more important than other. APIs should be more stable then the implementation. Therefore it needs to be clearly separated.
  • Level of abstraction and entry point
    It should be possible for an outsider to know what the code is about, and where to start reading from looking at the package tree.

Example:

com/company/module
  + feature1/
    - MainClass          // The entry point for exploring
    + api/               // Public interface, used by other features
    + domain/
      - AggregateRoot
      + api/             // Internal API, complements the public, used by web
      + impl/ 
    + persistence/       
    + web/               // presentation layer 
    + services/          // Rest or other remote API 
    + support/            
  + feature2/
  + support/             // Any support or utils used by more than on feature
    + io
    + config
    + persistence
    + web

This is just an example. It is quite formal. For example it defines 2 interfaces for feature1. Normally that is not required, but could be a good idea if used differently by different people. You may let the internal API extend the public.

I do not like the 'impl' or 'support' names, but they help separate the less important stuff from the important (domain and API). When it comes to naming I like to be as concrete as possible. If you have a package called 'utils' with 20 classes, move StringUtils to support/string, HttpUtil to support/http and so on.

Input text dialog Android

@LukeTaylor: I currently have the same task at hand (creating a popup/dialog that contains an EditText)..
Personally, I find the fully-dynamic route to be somewhat limiting in terms of creativity.

FULLY CUSTOM DIALOG LAYOUT :

Rather than relying entirely upon Code to create the Dialog, you can fully customize it like so :

1) - Create a new Layout Resource file.. This will act as your Dialog, allowing for full creative freedom!
NOTE: Refer to the Material Design guidelines to help keep things clean and on point.

2) - Give ID's to all of your View elements.. In my example code below, I have 1 EditText, and 2 Buttons.

3) - Create an Activity with a Button, for testing purposes.. We'll have it inflate and launch your Dialog!

public void buttonClick_DialogTest(View view) {

    AlertDialog.Builder mBuilder = new AlertDialog.Builder(MainActivity.this);

    //  Inflate the Layout Resource file you created in Step 1
    View mView = getLayoutInflater().inflate(R.layout.timer_dialog_layout, null);

    //  Get View elements from Layout file. Be sure to include inflated view name (mView)
    final EditText mTimerMinutes = (EditText) mView.findViewById(R.id.etTimerValue);
    Button mTimerOk = (Button) mView.findViewById(R.id.btnTimerOk);
    Button mTimerCancel = (Button) mView.findViewById(R.id.btnTimerCancel);

    //  Create the AlertDialog using everything we needed from above
    mBuilder.setView(mView);
    final AlertDialog timerDialog = mBuilder.create();

    //  Set Listener for the OK Button
    mTimerOk.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick (View view) {
            if (!mTimerMinutes.getText().toString().isEmpty()) {
                Toast.makeText(MainActivity.this, "You entered a Value!,", Toast.LENGTH_LONG).show();
            } else {
                Toast.makeText(MainActivity.this, "Please enter a Value!", Toast.LENGTH_LONG).show();
            }
        }
    });

    //  Set Listener for the CANCEL Button
    mTimerCancel.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick (View view) {
            timerDialog.dismiss();
        }
    });

    //  Finally, SHOW your Dialog!
    timerDialog.show();


    //  END OF buttonClick_DialogTest
}


Piece of cake! Full creative freedom! Just be sure to follow Material Guidelines ;)

I hope this helps someone! Let me know what you guys think!

How to attach a process in gdb

Try one of these:

gdb -p 12271
gdb /path/to/exe 12271

gdb /path/to/exe
(gdb) attach 12271

Understanding string reversal via slicing

Using extended slice syntax

word = input ("Type a word which you want to reverse: ")
def reverse(word):
  word = word[::-1]
  return word
print (reverse(word))

curl: (6) Could not resolve host: google.com; Name or service not known

Perhaps you have some very weird and restrictive SELinux rules in place?

If not, try strace -o /tmp/wtf -fF curl -v google.com and try to spot from /tmp/wtf output file what's going on.

SQLite select where empty?

It looks like you can simply do:

SELECT * FROM your_table WHERE some_column IS NULL OR some_column = '';

Test case:

CREATE TABLE your_table (id int, some_column varchar(10));

INSERT INTO your_table VALUES (1, NULL);
INSERT INTO your_table VALUES (2, '');
INSERT INTO your_table VALUES (3, 'test');
INSERT INTO your_table VALUES (4, 'another test');
INSERT INTO your_table VALUES (5, NULL);

Result:

SELECT id FROM your_table WHERE some_column IS NULL OR some_column = '';

id        
----------
1         
2         
5    

What are all codecs and formats supported by FFmpeg?

Codecs proper:

ffmpeg -codecs

Formats:

ffmpeg -formats

ImportError: No module named xlsxwriter

I have the same issue. It seems that pip is the problem. Try

pip uninstall xlsxwriter
easy_install xlsxwriter

Convert JSON to Map

Use JSON lib E.g. http://www.json.org/java/

// Assume you have a Map<String, String> in JSONObject jdata
@SuppressWarnings("unchecked")
Iterator<String> nameItr = jdata.keys();
Map<String, String> outMap = new HashMap<String, String>();
while(nameItr.hasNext()) {
    String name = nameItr.next();
    outMap.put(name, jdata.getString(name));

}

IIS7 - The request filtering module is configured to deny a request that exceeds the request content length

<configuration>
    <system.web>
        <httpRuntime maxRequestLength="1048576" />
    </system.web>
</configuration>

From here.

For IIS7 and above, you also need to add the lines below:

 <system.webServer>
   <security>
      <requestFiltering>
         <requestLimits maxAllowedContentLength="1073741824" />
      </requestFiltering>
   </security>
 </system.webServer>

Failed to load resource: the server responded with a status of 404 (Not Found) css

Use the following Code:-

../css/main.css

Note: The "../" is shorthand for "The containing directory", or "Up one directory".

If you don't know the previous folder this will be very helpful..

Clear dropdownlist with JQuery

I tried both .empty() as well as .remove() for my dropdown and both were slow. Since I had almost 4,000 options there.

I used .html("") which is much faster in my condition.
Which is below

  $(dropdown).html("");

How to get row data by clicking a button in a row in an ASP.NET gridview

 protected void btnS10_click(object sender, EventArgs e)
    {
        foreach (GridViewRow row in Grd.Rows)
        {
            CheckBox chk_Single = (CheckBox)row.FindControl("ChkSendOne");
            if (row.RowType == DataControlRowType.DataRow)
            {
                string id = (row.Cells[0].FindControl("lblSNo") as Label).Text;
                if (Convert.ToInt32(id) <= 10)
                {
                   
                    chk_Single.Checked = true;
                    if (chk_Single.Checked == true)
                    {
                        lblSelectedRecord.InnerText = (Convert.ToInt32(lblSelectedRecord.InnerText) + 1).ToString();
                    }
                }
            }
        }
    }

Is there an easy way to attach source in Eclipse?

Another thought for making that easier when using an automated build:

When you create a jar of one of your projects, also create a source files jar:
project.jar
project-src.jar

Instead of going into the build path options dialog to add a source reference to each jar, try the following: add one source reference through the dialog. Edit your .classpath and using the first jar entry as a template, add the source jar files to each of your other jars.

This way you can use Eclipse's navigation aids to their fullest while still using something more standalone to build your projects.

VBA: Conditional - Is Nothing

Based on your comment to Issun:

Thanks for the explanation. In my case, The object is declared and created prior to the If condition. So, How do I use If condition to check for < No Variables> ? In other words, I do not want to execute My_Object.Compute if My_Object has < No Variables>

You need to check one of the properties of the object. Without telling us what the object is, we cannot help you.

I did test several common objects and found that an instantiated Collection with no items added shows <No Variables> in the watch window. If your object is indeed a collection, you can check for the <No Variables> condition using the .Count property:

Sub TestObj()
Dim Obj As Object
    Set Obj = New Collection
    If Obj Is Nothing Then
        Debug.Print "Object not instantiated"
    Else
        If Obj.Count = 0 Then
            Debug.Print "<No Variables> (ie, no items added to the collection)"
        Else
            Debug.Print "Object instantiated and at least one item added"
        End If
    End If
End Sub

It is also worth noting that if you declare any object As New then the Is Nothing check becomes useless. The reason is that when you declare an object As New then it gets created automatically when it is first called, even if the first time you call it is to see if it exists!

Dim MyObject As New Collection
If MyObject Is Nothing Then  ' <--- This check always returns False

This does not seem to be the cause of your specific problem. But, since others may find this question through a Google search, I wanted to include it because it is a common beginner mistake.

How to jump to top of browser page

Without animation, you can use plain JS:

scroll(0,0)

With animation, check Nick's answer.

jQuery UI accordion that keeps multiple sections open?

Simple: active the accordion to a class, and then create divs with this, like multiples instances of accordion.

Like this:

JS

$(function() {
    $( ".accordion" ).accordion({
        collapsible: true,
        clearStyle: true,
        active: false,
    })
});

HTML

<div class="accordion">
    <h3>Title</h3>
    <p>lorem</p>
</div>
<div class="accordion">
    <h3>Title</h3>
    <p>lorem</p>
</div>
<div class="accordion">
    <h3>Title</h3>
    <p>lorem</p>
</div>

https://jsfiddle.net/sparhawk_odin/pm91whz3/

Inserting an item in a Tuple

one way is to convert it to list

>>> b=list(mytuple)
>>> b.append("something")
>>> a=tuple(b)

JavaScript - Getting HTML form values

I know this is an old post but maybe someone down the line can use this.

_x000D_
_x000D_
// use document.form["form-name"] to reference the form
const ccForm = document.forms["ccform"];

// bind the onsubmit property to a function to do some logic
ccForm.onsubmit = function(e) {

  // access the desired input through the var we setup
  let ccSelection = ccForm.ccselect.value;
  console.log(ccSelection);

  e.preventDefault();
}
_x000D_
<form name="ccform">
  <select name="ccselect">
    <option value="card1">Card 1</option>
    <option value="card2">Card 2</option>
    <option value="card3">Card 3</option>
  </select>
  <button type="submit">Enter</button>
</form>
_x000D_
_x000D_
_x000D_

Can I style an image's ALT text with CSS?

In Firefox and Chrome (and possibly more) we can insert the string ‘( .... )’ into the alt text of an image that hasn’t loaded.

_x000D_
_x000D_
img {_x000D_
  font-style: italic;_x000D_
  color: #c00;_x000D_
}_x000D_
_x000D_
img:after {_x000D_
  content: " (Image - Right click to reload if not loaded)";_x000D_
}_x000D_
_x000D_
img::after {_x000D_
  content: " (Image - Right click to reload if not loaded)";_x000D_
}
_x000D_
<img alt="Alt text - " />
_x000D_
_x000D_
_x000D_

Why is it that "No HTTP resource was found that matches the request URI" here?

WebApiConfig.Register(GlobalConfiguration.Configuration); should be on top.

How to restart remote MySQL server running on Ubuntu linux?

sudo service mysql stop;
sudo service mysql start;

If the above process will not work let's check one the given code above you can stop Mysql server and again start server

Can a class member function template be virtual?

No they can't. But:

template<typename T>
class Foo {
public:
  template<typename P>
  void f(const P& p) {
    ((T*)this)->f<P>(p);
  }
};

class Bar : public Foo<Bar> {
public:
  template<typename P>
  void f(const P& p) {
    std::cout << p << std::endl;
  }
};

int main() {
  Bar bar;

  Bar *pbar = &bar;
  pbar -> f(1);

  Foo<Bar> *pfoo = &bar;
  pfoo -> f(1);
};

has much the same effect if all you want to do is have a common interface and defer implementation to subclasses.

Max tcp/ip connections on Windows Server 2008

There is a limit on the number of half-open connections, but afaik not for active connections. Although it appears to depend on the type of Windows 2008 server, at least according to this MSFT employee:

It depends on the edition, Web and Foundation editions have connection limits while Standard, Enterprise, and Datacenter do not.

change text of button and disable button in iOS

Assuming that the button is a UIButton:

UIButton *button = …;
[button setEnabled:NO]; // disables
[button setTitle:@"Foo" forState:UIControlStateNormal]; // sets text

See the documentation for UIButton.

MSOnline can't be imported on PowerShell (Connect-MsolService error)

The following is needed:

  • MS Online Services Assistant needs to be downloaded and installed.
  • MS Online Module for PowerShell needs to be downloaded and installed
  • Connect to Microsoft Online in PowerShell

Source: http://www.msdigest.net/2012/03/how-to-connect-to-office-365-with-powershell/

Then Follow this one if you're running a 64bits computer: I’m running a x64 OS currently (Win8 Pro).

Copy the folder MSOnline from (1) –> (2) as seen here

1) C:\Windows\System32\WindowsPowerShell\v1.0\Modules(MSOnline)

2) C:\Windows\SysWOW64\WindowsPowerShell\v1.0\Modules(MSOnline)

Source: http://blog.clauskonrad.net/2013/06/powershell-and-c-cant-load-msonline.html

Hope this is better and can save some people's time

What are some ways of accessing Microsoft SQL Server from Linux?

I'd like to recommend Sqlectron. Besides being open source under MIT license it's multiplatform boosted by Electron. Its own definition is:

A simple and lightweight SQL client desktop with cross database and platform support

It currently supports PostgreSQL, MySQL, MS SQL Server, Cassandra and SQLite.

Laravel 5: Display HTML with Blade

For who using tinymce and markup within textarea:

{{ htmlspecialchars($text) }}

How to execute a function when page has fully loaded?

And here's a way to do it with PrototypeJS:

Event.observe(window, 'load', function(event) {
    // Do stuff
});

Adding a column to a data.frame

You can add a column to your data using various techniques. The quotes below come from the "Details" section of the relevant help text, [[.data.frame.

Data frames can be indexed in several modes. When [ and [[ are used with a single vector index (x[i] or x[[i]]), they index the data frame as if it were a list.

my.dataframe["new.col"] <- a.vector
my.dataframe[["new.col"]] <- a.vector

The data.frame method for $, treats x as a list

my.dataframe$new.col <- a.vector

When [ and [[ are used with two indices (x[i, j] and x[[i, j]]) they act like indexing a matrix

my.dataframe[ , "new.col"] <- a.vector

Since the method for data.frame assumes that if you don't specify if you're working with columns or rows, it will assume you mean columns.


For your example, this should work:

# make some fake data
your.df <- data.frame(no = c(1:4, 1:7, 1:5), h_freq = runif(16), h_freqsq = runif(16))

# find where one appears and 
from <- which(your.df$no == 1)
to <- c((from-1)[-1], nrow(your.df)) # up to which point the sequence runs

# generate a sequence (len) and based on its length, repeat a consecutive number len times
get.seq <- mapply(from, to, 1:length(from), FUN = function(x, y, z) {
            len <- length(seq(from = x[1], to = y[1]))
            return(rep(z, times = len))
         })

# when we unlist, we get a vector
your.df$group <- unlist(get.seq)
# and append it to your original data.frame. since this is
# designating a group, it makes sense to make it a factor
your.df$group <- as.factor(your.df$group)


   no     h_freq   h_freqsq group
1   1 0.40998238 0.06463876     1
2   2 0.98086928 0.33093795     1
3   3 0.28908651 0.74077119     1
4   4 0.10476768 0.56784786     1
5   1 0.75478995 0.60479945     2
6   2 0.26974011 0.95231761     2
7   3 0.53676266 0.74370154     2
8   4 0.99784066 0.37499294     2
9   5 0.89771767 0.83467805     2
10  6 0.05363139 0.32066178     2
11  7 0.71741529 0.84572717     2
12  1 0.10654430 0.32917711     3
13  2 0.41971959 0.87155514     3
14  3 0.32432646 0.65789294     3
15  4 0.77896780 0.27599187     3
16  5 0.06100008 0.55399326     3

How to display a confirmation dialog when clicking an <a> link?

Inline event handler

In the most simple way, you can use the confirm() function in an inline onclick handler.

<a href="delete.php?id=22" onclick="return confirm('Are you sure?')">Link</a>

Advanced event handling

But normally you would like to separate your HTML and Javascript, so I suggest you don't use inline event handlers, but put a class on your link and add an event listener to it.

<a href="delete.php?id=22" class="confirmation">Link</a>
...
<script type="text/javascript">
    var elems = document.getElementsByClassName('confirmation');
    var confirmIt = function (e) {
        if (!confirm('Are you sure?')) e.preventDefault();
    };
    for (var i = 0, l = elems.length; i < l; i++) {
        elems[i].addEventListener('click', confirmIt, false);
    }
</script>

This example will only work in modern browsers (for older IEs you can use attachEvent(), returnValue and provide an implementation for getElementsByClassName() or use a library like jQuery that will help with cross-browser issues). You can read more about this advanced event handling method on MDN.

jQuery

I'd like to stay far away from being considered a jQuery fanboy, but DOM manipulation and event handling are two areas where it helps the most with browser differences. Just for fun, here is how this would look with jQuery:

<a href="delete.php?id=22" class="confirmation">Link</a>
...
<!-- Include jQuery - see http://jquery.com -->
<script type="text/javascript">
    $('.confirmation').on('click', function () {
        return confirm('Are you sure?');
    });
</script>

Getting IP address of client

I use the following static helper method to retrieve the IP of a client:

public static String getClientIpAddr(HttpServletRequest request) {  
    String ip = request.getHeader("X-Forwarded-For");  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("Proxy-Client-IP");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("WL-Proxy-Client-IP");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_FORWARDED");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_X_CLUSTER_CLIENT_IP");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_CLIENT_IP");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_FORWARDED_FOR");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_FORWARDED");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("HTTP_VIA");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getHeader("REMOTE_ADDR");  
    }  
    if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
        ip = request.getRemoteAddr();  
    }  
    return ip;  
}

the easiest way to convert matrix to one row vector

You can use the function RESHAPE:

B = reshape(A.',1,[]);

jQuery: Currency Format Number

There is a plugin for that, jquery-formatcurrency.

You can set the decimal separator (default .) and currency symbol (default $) for custom formatting or use the built in International Support. The format for Bahasa Indonesia (Indonesia) - Indonesian (Indonesia) coded id-ID looks closest to what you have provided.

ASP.NET Core - Swashbuckle not creating swagger.json file

According to Microsoft: To serve the Swagger UI at the app's root (http://localhost:/), set the RoutePrefix property to an empty string:

app.UseSwaggerUI(c =>
{
c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
c.RoutePrefix = string.Empty;
});

Is SMTP based on TCP or UDP?

In theory SMTP can be handled by either TCP, UDP, or some 3rd party protocol.

As defined in RFC 821, RFC 2821, and RFC 5321:

SMTP is independent of the particular transmission subsystem and requires only a reliable ordered data stream channel.

In addition, the Internet Assigned Numbers Authority has allocated port 25 for both TCP and UDP for use by SMTP.

In practice however, most if not all organizations and applications only choose to implement the TCP protocol. For example, in Microsoft's port listing port 25 is only listed for TCP and not UDP.


The big difference between TCP and UDP that makes TCP ideal here is that TCP checks to make sure that every packet is received and re-sends them if they are not whereas UDP will simply send packets and not check for receipt. This makes UDP ideal for things like streaming video where every single packet isn't as important as keeping a continuous flow of packets from the server to the client.

Considering SMTP, it makes more sense to use TCP over UDP. SMTP is a mail transport protocol, and in mail every single packet is important. If you lose several packets in the middle of the message the recipient might not even receive the message and if they do they might be missing key information. This makes TCP more appropriate because it ensures that every packet is delivered.

How do you enable auto-complete functionality in Visual Studio C++ express edition?

Include the class that you are using Within your text file, then intelliSense will know where to look when you type within your text file. This works for me.

So it’s important to check the Unreal API to see where the included class is so that you have the path to type on the include line. Hope that makes sense.

Apache and IIS side by side (both listening to port 80) on windows2003

I see this is quite an old post, but came across this looking for an answer for this problem. After reading some of the answers they seem very long winded, so after about 5 mins I managed to solve the problem very simply as follows:

httpd.conf for Apache leave the listen port as 80 and 'Server Name' as FQDN/IP :80.

Now for IIS go to Administrative Services > IIS Manager > 'Sites' in the Left hand nav drop down > in the right window select the top line (default web site) then bindings on the right.

Now select http > edit and change to 81 and enter your local IP for the server/pc and in domain enter either your FQDN (www.domain.com) or external IP close.

Restart both servers ensure your ports are open on both router and firewall, done.

This sounds long winded but literally took 5 mins of playing about. works perfectly.

System: Windows 8, IIS 8, Apache 2.2

using mailto to send email with an attachment

If you are using c# on the desktop, you can use SimpleMapi. That way it will be sent using the default mail client, and the user has the option of reviewing the message before sending, just like mailto:.

To use it you add the Simple-MAPI.NET package (it's 13Kb), and run:

var mapi = new SimpleMapi();
mapi.AddRecipient(null, address, false);
mapi.Attach(path);
//mapi.Logon(ParentForm.Handle);    //not really necessary
mapi.Send(subject, body, true);

Convert double to float in Java

Convert Double to Float

public static Float convertToFloat(Double doubleValue) {
    return doubleValue == null ? null : doubleValue.floatValue();
}

Convert double to Float

public static Float convertToFloat(double doubleValue) {
    return (float) doubleValue;
}

org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]A child container failed during start

Went through the various resources on the net but none of them helped then i deleted the existing server and added the same server again and now it is working fine and the steps are

Window>>ShowView>>Servers>>RightClick>>Delete

and then add the server again as you have added previously.

Convert Date/Time for given Timezone - java

The solution is actually quite simple (pure, simple Java):

System.out.println(" NZ Local Time: 2011-10-06 03:35:05");
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime localNZ = LocalDateTime.parse("2011-10-06 03:35:05",formatter);
ZonedDateTime zonedNZ = ZonedDateTime.of(localNZ,ZoneId.of("+13:00"));
LocalDateTime localUTC = zonedNZ.withZoneSameInstant(ZoneId.of("UTC")).toLocalDateTime();
System.out.println("UTC Local Time: "+localUTC.format(formatter));

OUTPUT IS:

 NZ Local Time: 2011-10-06 03:35:05
UTC Local Time: 2011-10-05 14:35:05

Extract file basename without path and extension in bash

Here are oneliners:

  1. $(basename "${s%.*}")
  2. $(basename "${s}" ".${s##*.}")

I needed this, the same as asked by bongbang and w4etwetewtwet.

How to check if $_GET is empty?

I would use the following if statement because it is easier to read (and modify in the future)


if(!isset($_GET) || !is_array($_GET) || count($_GET)==0) {
   // empty, let's make sure it's an empty array for further reference
   $_GET=array();
   // or unset it 
   // or set it to null
   // etc...
}

How to downgrade python from 3.7 to 3.6

I would just recommend creating a new virtual environment and installing all the packages from the start as the wheels for some packages might have been installed for the previous version of the Python. I believe this is the safest way and you have two options.

  1. Creating a new virtual environment with venv:

    python3.6 -m venv -n new_env
    source venv_env/bin/activate
    
  2. Creating a conda environment:

    conda create -n new_env python=3.6
    conda activate new_env
    

The packages you install in an environment are built based on the Python version of the environment and if you do not carefully modify the existing environment, then, you can cause some incompatibilities between packages. That is why I would recommend a using a new environment built with Python 3.6.

Appending a vector to a vector

While saying "the compiler can reserve", why rely on it? And what about automatic detection of move semantics? And what about all that repeating of the container name with the begins and ends?

Wouldn't you want something, you know, simpler?

(Scroll down to main for the punchline)

#include <type_traits>
#include <vector>
#include <iterator>
#include <iostream>

template<typename C,typename=void> struct can_reserve: std::false_type {};

template<typename T, typename A>
struct can_reserve<std::vector<T,A>,void>:
    std::true_type
{};

template<int n> struct secret_enum { enum class type {}; };
template<int n>
using SecretEnum = typename secret_enum<n>::type;

template<bool b, int override_num=1>
using EnableFuncIf = typename std::enable_if< b, SecretEnum<override_num> >::type;
template<bool b, int override_num=1>
using DisableFuncIf = EnableFuncIf< !b, -override_num >;

template<typename C, EnableFuncIf< can_reserve<C>::value >... >
void try_reserve( C& c, std::size_t n ) {
  c.reserve(n);
}
template<typename C, DisableFuncIf< can_reserve<C>::value >... >
void try_reserve( C& c, std::size_t ) { } // do nothing

template<typename C,typename=void>
struct has_size_method:std::false_type {};
template<typename C>
struct has_size_method<C, typename std::enable_if<std::is_same<
  decltype( std::declval<C>().size() ),
  decltype( std::declval<C>().size() )
>::value>::type>:std::true_type {};

namespace adl_aux {
  using std::begin; using std::end;
  template<typename C>
  auto adl_begin(C&&c)->decltype( begin(std::forward<C>(c)) );
  template<typename C>
  auto adl_end(C&&c)->decltype( end(std::forward<C>(c)) );
}
template<typename C>
struct iterable_traits {
    typedef decltype( adl_aux::adl_begin(std::declval<C&>()) ) iterator;
    typedef decltype( adl_aux::adl_begin(std::declval<C const&>()) ) const_iterator;
};
template<typename C> using Iterator = typename iterable_traits<C>::iterator;
template<typename C> using ConstIterator = typename iterable_traits<C>::const_iterator;
template<typename I> using IteratorCategory = typename std::iterator_traits<I>::iterator_category;

template<typename C, EnableFuncIf< has_size_method<C>::value, 1>... >
std::size_t size_at_least( C&& c ) {
    return c.size();
}

template<typename C, EnableFuncIf< !has_size_method<C>::value &&
  std::is_base_of< std::random_access_iterator_tag, IteratorCategory<Iterator<C>> >::value, 2>... >
std::size_t size_at_least( C&& c ) {
    using std::begin; using std::end;
  return end(c)-begin(c);
};
template<typename C, EnableFuncIf< !has_size_method<C>::value &&
  !std::is_base_of< std::random_access_iterator_tag, IteratorCategory<Iterator<C>> >::value, 3>... >
std::size_t size_at_least( C&& c ) {
  return 0;
};

template < typename It >
auto try_make_move_iterator(It i, std::true_type)
-> decltype(make_move_iterator(i))
{
    return make_move_iterator(i);
}
template < typename It >
It try_make_move_iterator(It i, ...)
{
    return i;
}


#include <iostream>
template<typename C1, typename C2>
C1&& append_containers( C1&& c1, C2&& c2 )
{
  using std::begin; using std::end;
  try_reserve( c1, size_at_least(c1) + size_at_least(c2) );

  using is_rvref = std::is_rvalue_reference<C2&&>;
  c1.insert( end(c1),
             try_make_move_iterator(begin(c2), is_rvref{}),
             try_make_move_iterator(end(c2), is_rvref{}) );

  return std::forward<C1>(c1);
}

struct append_infix_op {} append;
template<typename LHS>
struct append_on_right_op {
  LHS lhs;
  template<typename RHS>
  LHS&& operator=( RHS&& rhs ) {
    return append_containers( std::forward<LHS>(lhs), std::forward<RHS>(rhs) );
  }
};

template<typename LHS>
append_on_right_op<LHS> operator+( LHS&& lhs, append_infix_op ) {
  return { std::forward<LHS>(lhs) };
}
template<typename LHS,typename RHS>
typename std::remove_reference<LHS>::type operator+( append_on_right_op<LHS>&& lhs, RHS&& rhs ) {
  typename std::decay<LHS>::type retval = std::forward<LHS>(lhs.lhs);
  return append_containers( std::move(retval), std::forward<RHS>(rhs) );
}

template<typename C>
void print_container( C&& c ) {
  for( auto&& x:c )
    std::cout << x << ",";
  std::cout << "\n";
};

int main() {
  std::vector<int> a = {0,1,2};
  std::vector<int> b = {3,4,5};
  print_container(a);
  print_container(b);
  a +append= b;
  const int arr[] = {6,7,8};
  a +append= arr;
  print_container(a);
  print_container(b);
  std::vector<double> d = ( std::vector<double>{-3.14, -2, -1} +append= a );
  print_container(d);
  std::vector<double> c = std::move(d) +append+ a;
  print_container(c);
  print_container(d);
  std::vector<double> e = c +append+ std::move(a);
  print_container(e);
  print_container(a);
}

hehe.

Now with move-data-from-rhs, append-array-to-container, append forward_list-to-container, move-container-from-lhs, thanks to @DyP's help.

Note that the above does not compile in clang thanks to the EnableFunctionIf<>... technique. In clang this workaround works.

Named tuple and default values for optional keyword arguments

Python 3.7

Use the defaults parameter.

>>> from collections import namedtuple
>>> fields = ('val', 'left', 'right')
>>> Node = namedtuple('Node', fields, defaults=(None,) * len(fields))
>>> Node()
Node(val=None, left=None, right=None)

Or better yet, use the new dataclasses library, which is much nicer than namedtuple.

>>> from dataclasses import dataclass
>>> from typing import Any
>>> @dataclass
... class Node:
...     val: Any = None
...     left: 'Node' = None
...     right: 'Node' = None
>>> Node()
Node(val=None, left=None, right=None)

Before Python 3.7

Set Node.__new__.__defaults__ to the default values.

>>> from collections import namedtuple
>>> Node = namedtuple('Node', 'val left right')
>>> Node.__new__.__defaults__ = (None,) * len(Node._fields)
>>> Node()
Node(val=None, left=None, right=None)

Before Python 2.6

Set Node.__new__.func_defaults to the default values.

>>> from collections import namedtuple
>>> Node = namedtuple('Node', 'val left right')
>>> Node.__new__.func_defaults = (None,) * len(Node._fields)
>>> Node()
Node(val=None, left=None, right=None)

Order

In all versions of Python, if you set fewer default values than exist in the namedtuple, the defaults are applied to the rightmost parameters. This allows you to keep some arguments as required arguments.

>>> Node.__new__.__defaults__ = (1,2)
>>> Node()
Traceback (most recent call last):
  ...
TypeError: __new__() missing 1 required positional argument: 'val'
>>> Node(3)
Node(val=3, left=1, right=2)

Wrapper for Python 2.6 to 3.6

Here's a wrapper for you, which even lets you (optionally) set the default values to something other than None. This does not support required arguments.

import collections
def namedtuple_with_defaults(typename, field_names, default_values=()):
    T = collections.namedtuple(typename, field_names)
    T.__new__.__defaults__ = (None,) * len(T._fields)
    if isinstance(default_values, collections.Mapping):
        prototype = T(**default_values)
    else:
        prototype = T(*default_values)
    T.__new__.__defaults__ = tuple(prototype)
    return T

Example:

>>> Node = namedtuple_with_defaults('Node', 'val left right')
>>> Node()
Node(val=None, left=None, right=None)
>>> Node = namedtuple_with_defaults('Node', 'val left right', [1, 2, 3])
>>> Node()
Node(val=1, left=2, right=3)
>>> Node = namedtuple_with_defaults('Node', 'val left right', {'right':7})
>>> Node()
Node(val=None, left=None, right=7)
>>> Node(4)
Node(val=4, left=None, right=7)

mysql query result in php variable

Of course there is. Check out mysql_query, and mysql_fetch_row if you use MySQL.
Example from PHP manual:

<?php
$result = mysql_query("SELECT id,email FROM people WHERE id = '42'");
if (!$result) {
    echo 'Could not run query: ' . mysql_error();
    exit;
}
$row = mysql_fetch_row($result);

echo $row[0]; // 42
echo $row[1]; // the email value
?>

Difference between jQuery .hide() and .css("display", "none")

jQuery('#id').css("display","block")

The display property can have many possible values, among which are block, inline, inline-block, and many more.

The .show() method doesn't set it necessarily to block, but rather resets it to what you defined it (if at all).

In the jQuery source code, you can see how they're setting the display property to "" (an empty string) to check what it was before any jQuery manipulation: little link.

On the other hand, hiding is done via display: none;, so you can consider .hide() and .css("display", "none") equivalent to some point.

It's recommended to use .show() and .hide() anyway to avoid any gotcha's (plus, they're shorter).

Get total number of items on Json object?

Is that your actual code? A javascript object (which is what you've given us) does not have a length property, so in this case exampleArray.length returns undefined rather than 5.

This stackoverflow explains the length differences between an object and an array, and this stackoverflow shows how to get the 'size' of an object.

XAMPP, Apache - Error: Apache shutdown unexpectedly

Note that whenever you change the default ports, your browser will not know about that. 80 and 443 seem to be standard in some way, so for example, if you changed 80 to 8080, you'll have to access your websites this way then:

localhost:8080/path_to_your_website.php

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

@hahn's answer required a bit of modification for it to work for me, but it is by far the most customizable thing I could get.

It didn't work for me, probably because I also have a HandlerInterceptorAdapter[??] but I kept getting a bad response from the server in that version. Here's my modification of it.

public class LoggableDispatcherServlet extends DispatcherServlet {

    private final Log logger = LogFactory.getLog(getClass());

    @Override
    protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {

        long startTime = System.currentTimeMillis();
        try {
            super.doDispatch(request, response);
        } finally {
            log(new ContentCachingRequestWrapper(request), new ContentCachingResponseWrapper(response),
                    System.currentTimeMillis() - startTime);
        }
    }

    private void log(HttpServletRequest requestToCache, HttpServletResponse responseToCache, long timeTaken) {
        int status = responseToCache.getStatus();
        JsonObject jsonObject = new JsonObject();
        jsonObject.addProperty("httpStatus", status);
        jsonObject.addProperty("path", requestToCache.getRequestURI());
        jsonObject.addProperty("httpMethod", requestToCache.getMethod());
        jsonObject.addProperty("timeTakenMs", timeTaken);
        jsonObject.addProperty("clientIP", requestToCache.getRemoteAddr());
        if (status > 299) {
            String requestBody = null;
            try {
                requestBody = requestToCache.getReader().lines().collect(Collectors.joining(System.lineSeparator()));
            } catch (IOException e) {
                e.printStackTrace();
            }
            jsonObject.addProperty("requestBody", requestBody);
            jsonObject.addProperty("requestParams", requestToCache.getQueryString());
            jsonObject.addProperty("tokenExpiringHeader",
                    responseToCache.getHeader(ResponseHeaderModifierInterceptor.HEADER_TOKEN_EXPIRING));
        }
        logger.info(jsonObject);
    }
}

'Conda' is not recognized as internal or external command

If you don't want to add Anaconda to env. path and you are using Windows try this:

  • Open cmd;
  • Type path to your folder instalation. It's something like: C:\Users\your_home folder\Anaconda3\Scripts
  • Test Anaconda, for exemple type conda --version.
  • Update Anaconda: conda update conda or conda update --all or conda update anaconda.

Update Spyder:

  • conda update qt pyqt
  • conda update spyder

SQL how to check that two tables has exactly the same data?

I wrote this to compare the results of a pretty nasty view I ported from Oracle to SQL Server. It creates a pair of temp tables, #DataVariances and #SchemaVariances, with differences in (you guessed it) the data in the tables and the schema of the tables themselves.

It requires both tables have a primary key, but you could drop it into tempdb with an identity column if the source tables don't have one.

declare @TableA_ThreePartName nvarchar(max) = ''
declare @TableB_ThreePartName nvarchar(max) = ''
declare @KeyName nvarchar(max) = ''

/***********************************************************************************************

    Script to compare two tables and return differneces in schema and data.

    Author: Devin Lamothe       2017-08-11

***********************************************************************************************/
set nocount on

-- Split three part name into database/schema/table
declare @Database_A nvarchar(max) = (
    select  left(@TableA_ThreePartName,charindex('.',@TableA_ThreePartName) - 1))
declare @Table_A nvarchar(max) = (
    select  right(@TableA_ThreePartName,len(@TableA_ThreePartName) - charindex('.',@TableA_ThreePartName,len(@Database_A) + 2)))
declare @Schema_A nvarchar(max) = (
    select  replace(replace(@TableA_ThreePartName,@Database_A + '.',''),'.' + @Table_A,''))

declare @Database_B nvarchar(max) = (
    select  left(@TableB_ThreePartName,charindex('.',@TableB_ThreePartName) - 1))
declare @Table_B nvarchar(max) = (
    select  right(@TableB_ThreePartName,len(@TableB_ThreePartName) - charindex('.',@TableB_ThreePartName,len(@Database_B) + 2)))
declare @Schema_B nvarchar(max) = (
    select  replace(replace(@TableB_ThreePartName,@Database_B + '.',''),'.' + @Table_B,''))

-- Get schema for both tables
declare @GetTableADetails nvarchar(max) = '
    use [' + @Database_A +']
        select  COLUMN_NAME
             ,  DATA_TYPE
          from  INFORMATION_SCHEMA.COLUMNS
         where  TABLE_NAME = ''' + @Table_A + '''
           and  TABLE_SCHEMA = ''' + @Schema_A + '''
    '
create table #Table_A_Details (
    ColumnName nvarchar(max)
,   DataType nvarchar(max)
)
insert into #Table_A_Details
exec (@GetTableADetails)

declare @GetTableBDetails nvarchar(max) = '
    use [' + @Database_B +']
        select  COLUMN_NAME
             ,  DATA_TYPE
          from  INFORMATION_SCHEMA.COLUMNS
         where  TABLE_NAME = ''' + @Table_B + '''
           and  TABLE_SCHEMA = ''' + @Schema_B + '''
    '
create table #Table_B_Details (
    ColumnName nvarchar(max)
,   DataType nvarchar(max)
)
insert into #Table_B_Details
exec (@GetTableBDetails)


-- Get differences in table schema
            select  ROW_NUMBER() over (order by
                        a.ColumnName
                    ,   b.ColumnName) as RowKey
                 ,  a.ColumnName as A_ColumnName
                 ,  a.DataType as A_DataType
                 ,  b.ColumnName as B_ColumnName
                 ,  b.DataType as B_DataType
              into  #FieldList
              from  #Table_A_Details a
   full outer join  #Table_B_Details b
                on  a.ColumnName = b.ColumnName
             where  a.ColumnName is null
                or  b.ColumnName is null
                or  a.DataType <> b.DataType

        drop table  #Table_A_Details
        drop table  #Table_B_Details

            select  coalesce(A_ColumnName,B_ColumnName) as ColumnName
                 ,  A_DataType
                 ,  B_DataType
              into  #SchemaVariances
              from  #FieldList

-- Get differences in table data
declare @LastColumn int = (select max(RowKey) from #FieldList)
declare @RowNumber int = 1
declare @ThisField nvarchar(max)
declare @TestSql nvarchar(max)



create table #DataVariances (
    TableKey            nvarchar(max)
,   FieldName           nvarchar(max)
,   TableA_Value        nvarchar(max)
,   TableB_Value        nvarchar(max)
)

delete from #FieldList where A_DataType in ('varbinary','image') or B_DataType in ('varbinary','image') 

while @RowNumber <= @LastColumn begin
    set @TestSql = '
        select  coalesce(a.[' + @KeyName + '],b.[' + @KeyName + ']) as TableKey
             ,  ''' + @ThisField + ''' as FieldName
             ,  a.[' + @ThisField + '] as [TableA_Value]
             ,  b.[' + @ThisField + '] as [TableB_Value]
          from  [' + @Database_A + '].[' + @Schema_A + '].[' + @Table_A + '] a 
    inner join  [' + @Database_B + '].[' + @Schema_B + '].[' + @Table_B + '] b
            on  a.[' + @KeyName + '] = b.[' + @KeyName + ']
         where  ltrim(rtrim(a.[' + @ThisField + '])) <> ltrim(rtrim(b.[' + @ThisField + ']))
            or (a.[' + @ThisField + '] is null and  b.[' + @ThisField + '] is not null)
            or (a.[' + @ThisField + '] is not null and  b.[' + @ThisField + '] is null)
'

insert into #DataVariances
exec (@TestSql)

set @RowNumber = @RowNumber + 1
set @ThisField = (select coalesce(A_ColumnName,B_ColumnName) from #FieldList a where RowKey = @RowNumber)

end

drop table #FieldList

print 'Query complete.  Select from #DataVariances to verify data integrity or #SchemaVariances to verify schemas match.  Data types varbinary and image are not checked.'

Why does my 'git branch' have no master?

I actually had the same problem with a completely new repository. I had even tried creating one with git checkout -b master, but it would not create the branch. I then realized if I made some changes and committed them, git created my master branch.

Add key value pair to all objects in array

You can do this with map()

_x000D_
_x000D_
var arrOfObj = [{_x000D_
  name: 'eve'_x000D_
}, {_x000D_
  name: 'john'_x000D_
}, {_x000D_
  name: 'jane'_x000D_
}];_x000D_
_x000D_
var result = arrOfObj.map(function(o) {_x000D_
  o.isActive = true;_x000D_
  return o;_x000D_
})_x000D_
_x000D_
console.log(result)
_x000D_
_x000D_
_x000D_

If you want to keep original array you can clone objects with Object.assign()

_x000D_
_x000D_
var arrOfObj = [{_x000D_
  name: 'eve'_x000D_
}, {_x000D_
  name: 'john'_x000D_
}, {_x000D_
  name: 'jane'_x000D_
}];_x000D_
_x000D_
var result = arrOfObj.map(function(el) {_x000D_
  var o = Object.assign({}, el);_x000D_
  o.isActive = true;_x000D_
  return o;_x000D_
})_x000D_
_x000D_
console.log(arrOfObj);_x000D_
console.log(result);
_x000D_
_x000D_
_x000D_

How do I use extern to share variables between source files?

A very short solution I use to allow a header file to contain the extern reference or actual implementation of an object. The file that actually contains the object just does #define GLOBAL_FOO_IMPLEMENTATION. Then when I add a new object to this file it shows up in that file also without me having to copy and paste the definition.

I use this pattern across multiple files. So in order to keep things as self contained as possible, I just reuse the single GLOBAL macro in each header. My header looks like this:

//file foo_globals.h
#pragma once  
#include "foo.h"  //contains definition of foo

#ifdef GLOBAL  
#undef GLOBAL  
#endif  

#ifdef GLOBAL_FOO_IMPLEMENTATION  
#define GLOBAL  
#else  
#define GLOBAL extern  
#endif  

GLOBAL Foo foo1;  
GLOBAL Foo foo2;


//file main.cpp
#define GLOBAL_FOO_IMPLEMENTATION
#include "foo_globals.h"

//file uses_extern_foo.cpp
#include "foo_globals.h

Creating/writing into a new file in Qt

#include <QFile>
#include <QCoreApplication>
#include <QTextStream>

int main(int argc, char *argv[])
{
    // Create a new file     
    QFile file("out.txt");
    file.open(QIODevice::WriteOnly | QIODevice::Text);
    QTextStream out(&file);
    out << "This file is generated by Qt\n";

    // optional, as QFile destructor will already do it:
    file.close(); 

    //this would normally start the event loop, but is not needed for this
    //minimal example:
    //return app.exec();

    return 0;
}

Switch case with conditions

function date_conversion(start_date){
    var formattedDate = new Date(start_date);
    var d = formattedDate.getDate();
    var m =  formattedDate.getMonth();
    var month;
    m += 1;  // JavaScript months are 0-11
    switch (m) {
        case 1: {
            month="Jan";
            break;
        }
        case 2: {
            month="Feb";
            break;
        }
        case 3: {
            month="Mar";
            break;
        }
        case 4: {
            month="Apr";
            break;
        }
        case 5: {
            month="May";
            break;
        }
        case 6: {
            month="Jun";
            break;
        }
        case 7: {
            month="Jul";
            break;
        }
        case 8: {
            month="Aug";
            break;
        }
        case 9: {
            month="Sep";
            break;
        }
        case 10: {
            month="Oct";
            break;
        }
        case 11: {
            month="Nov";
            break;
        }
        case 12: {
            month="Dec";
            break;
        }
    }
    var y = formattedDate.getFullYear();
    var now_date=d + "-" + month + "-" + y;
    return now_date;
}

How to VueJS router-link active style

As mentioned above by @Ricky vue-router automatically applies two active classes, .router-link-active and .router-link-exact-active, to the component.

So, to change active link css use:

.router-link-exact-active{
 //your desired design when link is clicked
font-weight: 700;
}

How to check if type of a variable is string?

If you do not want to depend on external libs, this works both for Python 2.7+ and Python 3 (http://ideone.com/uB4Kdc):

# your code goes here
s = ["test"];
#s = "test";
isString = False;

if(isinstance(s, str)):
    isString = True;
try:
    if(isinstance(s, basestring)):
        isString = True;
except NameError:
    pass;

if(isString):
    print("String");
else:
    print("Not String");

In practice, what are the main uses for the new "yield from" syntax in Python 3.3?

Wherever you invoke a generator from within a generator you need a "pump" to re-yield the values: for v in inner_generator: yield v. As the PEP points out there are subtle complexities to this which most people ignore. Non-local flow-control like throw() is one example given in the PEP. The new syntax yield from inner_generator is used wherever you would have written the explicit for loop before. It's not merely syntactic sugar, though: It handles all of the corner cases that are ignored by the for loop. Being "sugary" encourages people to use it and thus get the right behaviors.

This message in the discussion thread talks about these complexities:

With the additional generator features introduced by PEP 342, that is no longer the case: as described in Greg's PEP, simple iteration doesn't support send() and throw() correctly. The gymnastics needed to support send() and throw() actually aren't that complex when you break them down, but they aren't trivial either.

I can't speak to a comparison with micro-threads, other than to observe that generators are a type of paralellism. You can consider the suspended generator to be a thread which sends values via yield to a consumer thread. The actual implementation may be nothing like this (and the actual implementation is obviously of great interest to the Python developers) but this does not concern the users.

The new yield from syntax does not add any additional capability to the language in terms of threading, it just makes it easier to use existing features correctly. Or more precisely it makes it easier for a novice consumer of a complex inner generator written by an expert to pass through that generator without breaking any of its complex features.

ASP.NET MVC: No parameterless constructor defined for this object

I had this problem as well and thought I'd share since I can't find my problem above.

This was my code

return RedirectToAction("Overview", model.Id);

Calling this ActionResult:

public ActionResult Overview(int id)

I assumed it would be smart enough to figure out that the value I pass it is the id paramter for Overview, but it's not. This fixed it:

return RedirectToAction("Overview", new {id = model.Id});

How I can get and use the header file <graphics.h> in my C++ program?

graphics.h appears to something once bundled with Borland and/or Turbo C++, in the 90's.

http://www.daniweb.com/software-development/cpp/threads/17709/88149#post88149

It's unlikely that you will find any support for that file with modern compiler. For other graphics libraries check the list of "related" questions (questions related to this one). E.g., "A Simple, 2d cross-platform graphics library for c or c++?".

How to provide a file download from a JSF backing bean?

Introduction

You can get everything through ExternalContext. In JSF 1.x, you can get the raw HttpServletResponse object by ExternalContext#getResponse(). In JSF 2.x, you can use the bunch of new delegate methods like ExternalContext#getResponseOutputStream() without the need to grab the HttpServletResponse from under the JSF hoods.

On the response, you should set the Content-Type header so that the client knows which application to associate with the provided file. And, you should set the Content-Length header so that the client can calculate the download progress, otherwise it will be unknown. And, you should set the Content-Disposition header to attachment if you want a Save As dialog, otherwise the client will attempt to display it inline. Finally just write the file content to the response output stream.

Most important part is to call FacesContext#responseComplete() to inform JSF that it should not perform navigation and rendering after you've written the file to the response, otherwise the end of the response will be polluted with the HTML content of the page, or in older JSF versions, you will get an IllegalStateException with a message like getoutputstream() has already been called for this response when the JSF implementation calls getWriter() to render HTML.

Turn off ajax / don't use remote command!

You only need to make sure that the action method is not called by an ajax request, but that it is called by a normal request as you fire with <h:commandLink> and <h:commandButton>. Ajax requests and remote commands are handled by JavaScript which in turn has, due to security reasons, no facilities to force a Save As dialogue with the content of the ajax response.

In case you're using e.g. PrimeFaces <p:commandXxx>, then you need to make sure that you explicitly turn off ajax via ajax="false" attribute. In case you're using ICEfaces, then you need to nest a <f:ajax disabled="true" /> in the command component.

Generic JSF 2.x example

public void download() throws IOException {
    FacesContext fc = FacesContext.getCurrentInstance();
    ExternalContext ec = fc.getExternalContext();

    ec.responseReset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
    ec.setResponseContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ExternalContext#getMimeType() for auto-detection based on filename.
    ec.setResponseContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
    ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.

    OutputStream output = ec.getResponseOutputStream();
    // Now you can write the InputStream of the file to the above OutputStream the usual way.
    // ...

    fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}

Generic JSF 1.x example

public void download() throws IOException {
    FacesContext fc = FacesContext.getCurrentInstance();
    HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();

    response.reset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
    response.setContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ServletContext#getMimeType() for auto-detection based on filename.
    response.setContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
    response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.

    OutputStream output = response.getOutputStream();
    // Now you can write the InputStream of the file to the above OutputStream the usual way.
    // ...

    fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}

Common static file example

In case you need to stream a static file from the local disk file system, substitute the code as below:

File file = new File("/path/to/file.ext");
String fileName = file.getName();
String contentType = ec.getMimeType(fileName); // JSF 1.x: ((ServletContext) ec.getContext()).getMimeType(fileName);
int contentLength = (int) file.length();

// ...

Files.copy(file.toPath(), output);

Common dynamic file example

In case you need to stream a dynamically generated file, such as PDF or XLS, then simply provide output there where the API being used expects an OutputStream.

E.g. iText PDF:

String fileName = "dynamic.pdf";
String contentType = "application/pdf";

// ...

Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, output);
document.open();
// Build PDF content here.
document.close();

E.g. Apache POI HSSF:

String fileName = "dynamic.xls";
String contentType = "application/vnd.ms-excel";

// ...

HSSFWorkbook workbook = new HSSFWorkbook();
// Build XLS content here.
workbook.write(output);
workbook.close();

Note that you cannot set the content length here. So you need to remove the line to set response content length. This is technically no problem, the only disadvantage is that the enduser will be presented an unknown download progress. In case this is important, then you really need to write to a local (temporary) file first and then provide it as shown in previous chapter.

Utility method

If you're using JSF utility library OmniFaces, then you can use one of the three convenient Faces#sendFile() methods taking either a File, or an InputStream, or a byte[], and specifying whether the file should be downloaded as an attachment (true) or inline (false).

public void download() throws IOException {
    Faces.sendFile(file, true);
}

Yes, this code is complete as-is. You don't need to invoke responseComplete() and so on yourself. This method also properly deals with IE-specific headers and UTF-8 filenames. You can find source code here.

How do you create a REST client for Java?

I am currently using https://github.com/kevinsawicki/http-request I like their simplicity and the way examples are shown, but mostly I was sold when I read:

What are the dependencies?

None. The goal of this library is to be a single class class with some inner static classes. The test project does require Jetty in order to test requests against an actual HTTP server implementation.

which sorted out some problems on a java 1.6 project. As for decoding json into objects gson is just invincible :)

How to print a list in Python "nicely"

As the other answers suggest pprint module does the trick.
Nonetheless, in case of debugging where you might need to put the entire list into some log file, one might have to use pformat method along with module logging along with pprint.

import logging
from pprint import pformat

logger = logging.getLogger('newlogger')
handler = logging.FileHandler('newlogger.log')

formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s')
handler.setFormatter(formatter)

logger.addHandler(handler) 
logger.setLevel(logging.WARNING)

data = [ (i, { '1':'one',
           '2':'two',
           '3':'three',
           '4':'four',
           '5':'five',
           '6':'six',
           '7':'seven',
           '8':'eight',
           })
         for i in xrange(3)
      ]

logger.error(pformat(data))

And if you need to directly log it to a File, one would have to specify an output stream, using the stream keyword. Ref

from pprint import pprint

with open('output.txt', 'wt') as out:
   pprint(myTree, stream=out)

See Stefano Sanfilippo's answer

importing a CSV into phpmyadmin

Using the LOAD DATA INFILE SQL statement you can import the CSV file, but you can't update data. However, there is a trick you can use.

  • Create another temporary table to use for the import
  • Load onto this table from the CSC

    LOAD DATA LOCAL INFILE '/file.csv'
    INTO TABLE temp_table
    FIELDS TERMINATED BY ','
    LINES TERMINATED BY '\n'
    (field1, field2, field3); 
    
  • UPDATE the real table joining the table

    UPDATE maintable
    INNER JOIN temp_table A USING (field1)
    SET maintable.field1 = temp_table.field1
    

Test method is inconclusive: Test wasn't run. Error?

For me the issue was an asynchronous call which was not waited in any way.

   dc.Start(); // Asynchronous, it is mocked on this particular test, so i did not bother blocking the test.

Changed it to :

   dc.Start().ContinueWith(t =>
   {
        waitHandle.Set();
   });

   waitHandle.WaitOne(60000); // wait dc start

And the test began to be applicable again.

Stop absolutely positioned div from overlapping text

Put a z-indez of -1 on your absolute (or relative) positioned element.

This will pull it out of the stacking context. (I think.) Read more wonderful things about "stacking contexts" here: https://philipwalton.com/articles/what-no-one-told-you-about-z-index/

Android: How can I validate EditText input?

If you want nice validation popups and images when an error occurs you can use the setError method of the EditText class as I describe here

Screenshot of the use of setError taken from Donn Felker, the author of the linked post

Is mongodb running?

I know this is for php, but I got here looking for a solution for node. Using mongoskin:

mongodb.admin().ping(function(err) {
    if(err === null)
        // true - you got a conntion, congratulations
    else if(err.message.indexOf('failed to connect') !== -1)
        // false - database isn't around
    else
        // actual error, do something about it
})

With other drivers, you can attempt to make a connection and if it fails, you know the mongo server's down. Mongoskin needs to actually make some call (like ping) because it connects lazily. For php, you can use the try-to-connect method. Make a script!

PHP:

$dbIsRunning = true
try {
  $m = new MongoClient('localhost:27017');
} catch($e) {
  $dbIsRunning = false
}

Java 8, Streams to find the duplicate elements

A multiset is a structure maintaining the number of occurrences for each element. Using Guava implementation:

Set<Integer> duplicated =
        ImmutableMultiset.copyOf(numbers).entrySet().stream()
                .filter(entry -> entry.getCount() > 1)
                .map(Multiset.Entry::getElement)
                .collect(Collectors.toSet());

How to INNER JOIN 3 tables using CodeIgniter

it should be like that,

$this->db->select('*');    
$this->db->from('table1');
$this->db->join('table2', 'table1.id = table2.id');
$this->db->join('table3', 'table1.id = table3.id');
$query = $this->db->get();

as per CodeIgniters active record framework

log4j:WARN No appenders could be found for logger in web.xml

If you want to configure for the standalone log4j applications, you can use the BasicConfigurator. This solution won't be good for the web applications like Spring environment.

You need to write-

BasicConfigurator.configure();

or

ServletContext sc = config.getServletContext();
String log4jLocation = config.getInitParameter("log4j-properties-location");
String webAppPath = sc.getRealPath("/");
String log4jProp = webAppPath + log4jLocation;
PropertyConfigurator.configure(log4jProp);

Algorithm for solving Sudoku

Here is my sudoku solver in python. It uses simple backtracking algorithm to solve the puzzle. For simplicity no input validations or fancy output is done. It's the bare minimum code which solves the problem.

Algorithm

  1. Find all legal values of a given cell
  2. For each legal value, Go recursively and try to solve the grid

Solution

It takes 9X9 grid partially filled with numbers. A cell with value 0 indicates that it is not filled.

Code

def findNextCellToFill(grid, i, j):
        for x in range(i,9):
                for y in range(j,9):
                        if grid[x][y] == 0:
                                return x,y
        for x in range(0,9):
                for y in range(0,9):
                        if grid[x][y] == 0:
                                return x,y
        return -1,-1

def isValid(grid, i, j, e):
        rowOk = all([e != grid[i][x] for x in range(9)])
        if rowOk:
                columnOk = all([e != grid[x][j] for x in range(9)])
                if columnOk:
                        # finding the top left x,y co-ordinates of the section containing the i,j cell
                        secTopX, secTopY = 3 *(i//3), 3 *(j//3) #floored quotient should be used here. 
                        for x in range(secTopX, secTopX+3):
                                for y in range(secTopY, secTopY+3):
                                        if grid[x][y] == e:
                                                return False
                        return True
        return False

def solveSudoku(grid, i=0, j=0):
        i,j = findNextCellToFill(grid, i, j)
        if i == -1:
                return True
        for e in range(1,10):
                if isValid(grid,i,j,e):
                        grid[i][j] = e
                        if solveSudoku(grid, i, j):
                                return True
                        # Undo the current cell for backtracking
                        grid[i][j] = 0
        return False

Testing the code


>>> input = [[5,1,7,6,0,0,0,3,4],[2,8,9,0,0,4,0,0,0],[3,4,6,2,0,5,0,9,0],[6,0,2,0,0,0,0,1,0],[0,3,8,0,0,6,0,4,7],[0,0,0,0,0,0,0,0,0],[0,9,0,0,0,0,0,7,8],[7,0,3,4,0,0,5,6,0],[0,0,0,0,0,0,0,0,0]]
>>> solveSudoku(input)
True
>>> input
[[5, 1, 7, 6, 9, 8, 2, 3, 4], [2, 8, 9, 1, 3, 4, 7, 5, 6], [3, 4, 6, 2, 7, 5, 8, 9, 1], [6, 7, 2, 8, 4, 9, 3, 1, 5], [1, 3, 8, 5, 2, 6, 9, 4, 7], [9, 5, 4, 7, 1, 3, 6, 8, 2], [4, 9, 5, 3, 6, 2, 1, 7, 8], [7, 2, 3, 4, 8, 1, 5, 6, 9], [8, 6, 1, 9, 5, 7, 4, 2, 3]]

The above one is very basic backtracking algorithm which is explained at many places. But the most interesting and natural of the sudoku solving strategies I came across is this one from here

Change navbar text color Bootstrap

Make it the following:

.nav.navbar-nav.navbar-right li a {
    color: blue;
}

The above will target the specific links, which is what you want, versus styling the entire list blue, which is what you were initially doing. Here is a JsFiddle.

The other way would be creating another class and implementing it like so:

HTML

<li><a href="#" class="color-me"><span class="glyphicon glyphicon-list-alt"></span> R&eacute;sum&eacute;</a></li>

CSS

.color-me{
    color:blue;
}

Also demonstrated in this JsFiddle

JS search in object values

I needed to perform a search on a large object and return the addresses of the matches, not just the matched values themselves.

This function searches an object for a string (or alternatively, uses a callback function to perform custom logic) and keeps track of where the value was found within the object. It also avoids circular references.

_x000D_
_x000D_
//Search function_x000D_
var locateInObject = function(obj, key, find, result, currentLocation){_x000D_
  if(obj === null) return;_x000D_
  result = result||{done:[],found:{}};_x000D_
  if(typeof obj == 'object'){_x000D_
    result.done.push(obj);_x000D_
  }_x000D_
  currentLocation = currentLocation||key;_x000D_
  var keys = Object.keys(obj);_x000D_
  for(var k=0; k<keys.length; ++k){_x000D_
    var done = false;_x000D_
    for(var d=0; d<result.done.length; ++d){_x000D_
      if(result.done[d] === obj[keys[k]]){_x000D_
        done = true;_x000D_
        break;_x000D_
      }_x000D_
    }_x000D_
    if(!done){_x000D_
      var location = currentLocation+'.'+keys[k];_x000D_
      if(typeof obj[keys[k]] == 'object'){_x000D_
        locateInObject(obj[keys[k]], keys[k], find, result, location)_x000D_
      }else if((typeof find == 'string' && obj[keys[k]].toString().indexOf(find) > -1) || (typeof find == 'function' && find(obj[keys[k]], keys[k]))){_x000D_
        result.found[location] = obj[keys[k]];_x000D_
      }_x000D_
    }_x000D_
  }_x000D_
  return result.found;_x000D_
}_x000D_
_x000D_
//Test data_x000D_
var test = {_x000D_
  key1: {_x000D_
    keyA: 123,_x000D_
    keyB: "string"_x000D_
  },_x000D_
  key2: {_x000D_
    keyC: [_x000D_
      {_x000D_
        keyI: "string123",_x000D_
        keyII: 2.3_x000D_
      },_x000D_
      "string"_x000D_
    ],_x000D_
    keyD: null_x000D_
  },_x000D_
  key3: [_x000D_
    1,_x000D_
    2,_x000D_
    123,_x000D_
    "testString"_x000D_
  ],_x000D_
  key4: "123string"_x000D_
}_x000D_
//Add a circular reference_x000D_
test.key5 = test;_x000D_
_x000D_
//Tests_x000D_
console.log(locateInObject(test, 'test', 'string'))_x000D_
console.log(locateInObject(test, 'test', '123'))_x000D_
console.log(locateInObject(test, 'test', function(val, key){ return key.match(/key\d/) && val.indexOf('string') > -1}))
_x000D_
_x000D_
_x000D_

How do I print part of a rendered HTML page in JavaScript?

You could use a print stylesheet, but this will affect all print functions.

You could try having a print stylesheet externalally, and it is included via JavaScript when a button is pressed, and then call window.print(), then after that remove it.

$lookup on ObjectId's in an array

Starting with MongoDB v3.4 (released in 2016), the $lookup aggregation pipeline stage can also work directly with an array. There is no need for $unwind any more.

This was tracked in SERVER-22881.

Binding ConverterParameter

The ConverterParameter property can not be bound because it is not a dependency property.

Since Binding is not derived from DependencyObject none of its properties can be dependency properties. As a consequence, a Binding can never be the target object of another Binding.

There is however an alternative solution. You could use a MultiBinding with a multi-value converter instead of a normal Binding:

<Style TargetType="FrameworkElement">
    <Setter Property="Visibility">
        <Setter.Value>
            <MultiBinding Converter="{StaticResource AccessLevelToVisibilityConverter}">
                <Binding Path="Tag" RelativeSource="{RelativeSource Mode=FindAncestor,
                                                     AncestorType=UserControl}"/>
                <Binding Path="Tag" RelativeSource="{RelativeSource Mode=Self}"/>
            </MultiBinding>
        </Setter.Value>
    </Setter>
</Style>

The multi-value converter gets an array of source values as input:

public class AccessLevelToVisibilityConverter : IMultiValueConverter
{
    public object Convert(
        object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        return values.All(v => (v is bool && (bool)v))
            ? Visibility.Visible
            : Visibility.Hidden;
    }

    public object[] ConvertBack(
        object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

concat yesterdays date with a specific time

where date_dt = to_date(to_char(sysdate-1, 'YYYY-MM-DD') || ' 19:16:08', 'YYYY-MM-DD HH24:MI:SS') 

should work.

fatal: does not appear to be a git repository

I had a similar problem when using TFS 2017. I was not able to push or pull GIT repositories. Eventually I reinstalled TFS 2017, making sure that I installed TFS 2017 with an SSH Port different from 22 (in my case, I chose 8022). After that, push and pull became possible against TFS using SSH.

Flutter- wrapping text

If it's a single text widget that you want to wrap, you can either use Flexible or Expanded widgets.

Expanded(
  child: Text('Some lengthy text for testing'),
)

or

Flexible(
  child: Text('Some lengthy text for testing'),
)

For multiple widgets, you may choose Wrap widget. For further details checkout this

Timing Delays in VBA

For MS Access: Launch a hidden form with Me.TimerInterval set and a Form_Timer event handler. Put your to-be-delayed code in the Form_Timer routine - exiting the routine after each execution.

E.g.:

Private Sub Form_Load()
    Me.TimerInterval = 30000 ' 30 sec
End Sub

Private Sub Form_Timer()

    Dim lngTimerInterval  As Long: lngTimerInterval = Me.TimerInterval

    Me.TimerInterval = 0

    '<Your Code goes here>

    Me.TimerInterval = lngTimerInterval
End Sub

"Your Code goes here" will be executed 30 seconds after the form is opened and 30 seconds after each subsequent execution.

Close the hidden form when done.

Access files in /var/mobile/Containers/Data/Application without jailbreaking iPhone

If this is your app, if you connect the device to your computer, you can use the "Devices" option on Xcode's "Window" menu and then download the app's data container to your computer. Just select your app from the list of installed apps, and click on the "gear" icon and choose "Download Container".

enter image description here

Once you've downloaded it, right click on the file in the Finder and choose "Show Package Contents".

Transparent image - background color

If I understand you right, you can do this:

<img src="image.png" style="background-color:red;" />

In fact, you can even apply a whole background-image to the image, resulting in two "layers" without the need for multi-background support in the browser ;)

Angular JS POST request not sending JSON data

$http({
    url: '/api/user',
    method: "POST",
    data: angular.toJson(yourData)
}).success(function (data, status, headers, config) {
    $scope.users = data.users;
}).error(function (data, status, headers, config) {
    $scope.status = status + ' ' + headers;
});

Why are iframes considered dangerous and a security risk?

"Dangerous" and "Security risk" are not the first things that spring to mind when people mention iframes … but they can be used in clickjacking attacks.

How do I get started with Node.js

Use the source, Luke.

No, but seriously I found that building Node.js from source, running the tests, and looking at the benchmarks did get me on the right track. From there, the .js files in the lib directory are a good place to look, especially the file http.js.

Update: I wrote this answer over a year ago, and since that time there has an explosion in the number of great resources available for people learning Node.js. Though I still believe diving into the source is worthwhile, I think that there are now better ways to get started. I would suggest some of the books on Node.js that are starting to come out.

Conda uninstall one package and one package only

You can use conda remove --force.

The documentation says:

--force               Forces removal of a package without removing packages
                      that depend on it. Using this option will usually
                      leave your environment in a broken and inconsistent
                      state

how to find array size in angularjs

You can find the number of members in a Javascript array by using its length property:

var number = $scope.names.length;

Docs - Array.prototype.length

In a Dockerfile, How to update PATH environment variable?

This is discouraged (if you want to create/distribute a clean Docker image), since the PATH variable is set by /etc/profile script, the value can be overridden.

head /etc/profile:

if [ "`id -u`" -eq 0 ]; then
  PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
else
  PATH="/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games"
fi
export PATH

At the end of the Dockerfile, you could add:

RUN echo "export PATH=$PATH" > /etc/environment

So PATH is set for all users.

Getting current unixtimestamp using Moment.js

for UNIX time-stamp in milliseconds

moment().format('x') // lowerCase x

for UNIX time-stamp in seconds moment().format('X') // capital X

JavaScript: Parsing a string Boolean value?

I shamelessly converted Apache Common's toBoolean to JavaScript:

JSFiddle: https://jsfiddle.net/m2efvxLm/1/

Code:

_x000D_
_x000D_
function toBoolean(str) {_x000D_
  if (str == "true") {_x000D_
    return true;_x000D_
  }_x000D_
  if (!str) {_x000D_
    return false;_x000D_
  }_x000D_
  switch (str.length) {_x000D_
    case 1: {_x000D_
      var ch0 = str.charAt(0);_x000D_
      if (ch0 == 'y' || ch0 == 'Y' ||_x000D_
          ch0 == 't' || ch0 == 'T' ||_x000D_
          ch0 == '1') {_x000D_
        return true;_x000D_
      }_x000D_
      if (ch0 == 'n' || ch0 == 'N' ||_x000D_
          ch0 == 'f' || ch0 == 'F' ||_x000D_
          ch0 == '0') {_x000D_
        return false;_x000D_
      }_x000D_
      break;_x000D_
    }_x000D_
    case 2: {_x000D_
      var ch0 = str.charAt(0);_x000D_
      var ch1 = str.charAt(1);_x000D_
      if ((ch0 == 'o' || ch0 == 'O') &&_x000D_
          (ch1 == 'n' || ch1 == 'N') ) {_x000D_
        return true;_x000D_
      }_x000D_
      if ((ch0 == 'n' || ch0 == 'N') &&_x000D_
          (ch1 == 'o' || ch1 == 'O') ) {_x000D_
        return false;_x000D_
      }_x000D_
      break;_x000D_
    }_x000D_
    case 3: {_x000D_
      var ch0 = str.charAt(0);_x000D_
      var ch1 = str.charAt(1);_x000D_
      var ch2 = str.charAt(2);_x000D_
      if ((ch0 == 'y' || ch0 == 'Y') &&_x000D_
          (ch1 == 'e' || ch1 == 'E') &&_x000D_
          (ch2 == 's' || ch2 == 'S') ) {_x000D_
        return true;_x000D_
      }_x000D_
      if ((ch0 == 'o' || ch0 == 'O') &&_x000D_
          (ch1 == 'f' || ch1 == 'F') &&_x000D_
          (ch2 == 'f' || ch2 == 'F') ) {_x000D_
        return false;_x000D_
      }_x000D_
      break;_x000D_
    }_x000D_
    case 4: {_x000D_
      var ch0 = str.charAt(0);_x000D_
      var ch1 = str.charAt(1);_x000D_
      var ch2 = str.charAt(2);_x000D_
      var ch3 = str.charAt(3);_x000D_
      if ((ch0 == 't' || ch0 == 'T') &&_x000D_
          (ch1 == 'r' || ch1 == 'R') &&_x000D_
          (ch2 == 'u' || ch2 == 'U') &&_x000D_
          (ch3 == 'e' || ch3 == 'E') ) {_x000D_
        return true;_x000D_
      }_x000D_
      break;_x000D_
    }_x000D_
    case 5: {_x000D_
      var ch0 = str.charAt(0);_x000D_
      var ch1 = str.charAt(1);_x000D_
      var ch2 = str.charAt(2);_x000D_
      var ch3 = str.charAt(3);_x000D_
      var ch4 = str.charAt(4);_x000D_
      if ((ch0 == 'f' || ch0 == 'F') &&_x000D_
          (ch1 == 'a' || ch1 == 'A') &&_x000D_
          (ch2 == 'l' || ch2 == 'L') &&_x000D_
          (ch3 == 's' || ch3 == 'S') &&_x000D_
          (ch4 == 'e' || ch4 == 'E') ) {_x000D_
        return false;_x000D_
      }_x000D_
      break;_x000D_
    }_x000D_
    default:_x000D_
      break;_x000D_
  }_x000D_
_x000D_
  return false;_x000D_
}_x000D_
console.log(toBoolean("yEs")); // true_x000D_
console.log(toBoolean("yES")); // true_x000D_
console.log(toBoolean("no")); // false_x000D_
console.log(toBoolean("NO")); // false_x000D_
console.log(toBoolean("on")); // true_x000D_
console.log(toBoolean("oFf")); // false
_x000D_
Inspect this element, and view the console output.
_x000D_
_x000D_
_x000D_

Difference between session affinity and sticky session?

This article clarifies the question for me and discusses other types of load balancer persistence.

Dave's Thoughts: Load balancer persistence (sticky sessions)

How can I display a list view in an Android Alert Dialog?

Isn't it smoother to make a method to be called after the creation of the EditText unit in an AlertDialog, for general use?

public static void EditTextListPicker(final Activity activity, final EditText EditTextItem, final String SelectTitle, final String[] SelectList) {
    EditTextItem.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            AlertDialog.Builder builder = new AlertDialog.Builder(activity);
            builder.setTitle(SelectTitle);
            builder.setItems(SelectList, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialogInterface, int item) {
                    EditTextItem.setText(SelectList[item]);
                }
            });
            builder.create().show();
            return false;
        }
    });
}

How to Compare two strings using a if in a stored procedure in sql server 2008?

You can also try this for match string.

DECLARE @temp1 VARCHAR(1000)
    SET @temp1 = '<li>Error in connecting server.</li>'
DECLARE @temp2 VARCHAR(1000)
    SET @temp2 = '<li>Error in connecting server. connection timeout.</li>'

IF @temp1 like '%Error in connecting server.%' OR @temp1 like '%Error in connecting server. connection timeout.%'
  SELECT 'yes'
ELSE
  SELECT 'no'

How to get Database Name from Connection String using SqlConnectionStringBuilder

You can use the provider-specific ConnectionStringBuilder class (within the appropriate namespace), or System.Data.Common.DbConnectionStringBuilder to abstract the connection string object if you need to. You'd need to know the provider-specific keywords used to designate the information you're looking for, but for a SQL Server example you could do either of these two things:

System.Data.SqlClient.SqlConnectionStringBuilder builder = new System.Data.SqlClient.SqlConnectionStringBuilder(connectionString);

string server = builder.DataSource;
string database = builder.InitialCatalog;

or

System.Data.Common.DbConnectionStringBuilder builder = new System.Data.Common.DbConnectionStringBuilder();

builder.ConnectionString = connectionString;

string server = builder["Data Source"] as string;
string database = builder["Initial Catalog"] as string;

How to convert string to integer in PowerShell

Use:

$filelist = @("11", "1", "2")
$filelist | sort @{expression={[int]$_}} | % {$newName = [string]([int]$_ + 1)}
New-Item $newName -ItemType Directory

Optimal way to concatenate/aggregate strings

For those of us who found this and are not using Azure SQL Database:

STRING_AGG() in PostgreSQL, SQL Server 2017 and Azure SQL
https://www.postgresql.org/docs/current/static/functions-aggregate.html
https://docs.microsoft.com/en-us/sql/t-sql/functions/string-agg-transact-sql

GROUP_CONCAT() in MySQL
http://dev.mysql.com/doc/refman/5.7/en/group-by-functions.html#function_group-concat

(Thanks to @Brianjorden and @milanio for Azure update)

Example Code:

select Id
, STRING_AGG(Name, ', ') Names 
from Demo
group by Id

SQL Fiddle: http://sqlfiddle.com/#!18/89251/1