Programs & Examples On #Dom traversal

The process of traversing the Document Object Model (DOM) tree and finding nodes based on certain criterion.

How to select a single child element using jQuery?

<html>
<title>

    </title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" type="text/css" href="assets/css/bootstrap.css">
<body>




<!-- <asp:LinkButton ID="MoreInfoButton" runat="server" Text="<%#MoreInfo%>" > -->
 <!-- </asp:LinkButton> -->
<!-- </asp:LinkButton> -->

<br />
<asp:Repeater ID="Repeater1" runat="server" DataSourceID="SqlDataSource1">
<div>
<a><span id="imgDownArrow_0" class="glyphicon glyphicon-chevron-right " runat="server"> MoreInformation</span></a>
<div id="parent" class="dataContentSectionMessages" style="display:none">
    <!-- repeater1 starts -->
        <!-- <sc:text field="Event Description" runat="server" item="<%#Container.DataItem %>" /> -->
            <ul  >
                <li ><h6><strong>lorem</strong></h6></li>
                <li ><h6><strong>An assigned contact who knows you and your lorem analysis system</strong></h6></li>
                <li ><h6><strong>Internet accessible on-demand information and an easy to use internet shop</strong></h6></li>
                <li ><h6><strong>Extensive and flexible repair capabilities at any location</strong></h6></li>
                <li ><h6><strong>Full Service Contracts</strong></h6></li>
                <li ><h6><strong>Maintenance Contracts</strong></h6></li>
            </ul>
    <!-- repeater1 ends -->
</div>
</div>
<div>
<a><span id="imgDownArrow_0" class="glyphicon glyphicon-chevron-right " runat="server"> MoreInformation</span></a>
<div id="parent" class="dataContentSectionMessages" style="display:none">
    <!-- repeater1 starts -->
        <!-- <sc:text field="Event Description" runat="server" item="<%#Container.DataItem %>" /> -->
            <ul  >
                <li ><h6><strong>lorem</strong></h6></li>
                <li ><h6><strong>An assigned contact who knows you and your lorem analysis system</strong></h6></li>
                <li ><h6><strong>Internet accessible on-demand information and an easy to use internet shop</strong></h6></li>
                <li ><h6><strong>Extensive and flexible repair capabilities at any location</strong></h6></li>
                <li ><h6><strong>Full Service Contracts</strong></h6></li>
                <li ><h6><strong>Maintenance Contracts</strong></h6></li>
            </ul>
    <!-- repeater1 ends -->
</div>
</div>
<div>
<a><span id="imgDownArrow_0" class="glyphicon glyphicon-chevron-right " runat="server"> MoreInformation</span></a>
<div id="parent" class="dataContentSectionMessages" style="display:none">
    <!-- repeater1 starts -->
        <!-- <sc:text field="Event Description" runat="server" item="<%#Container.DataItem %>" /> -->
            <ul  >
                <li ><h6><strong>lorem</strong></h6></li>
                <li ><h6><strong>An assigned contact who knows you and your lorem analysis system</strong></h6></li>
                <li ><h6><strong>Internet accessible on-demand information and an easy to use internet shop</strong></h6></li>
                <li ><h6><strong>Extensive and flexible repair capabilities at any location</strong></h6></li>
                <li ><h6><strong>Full Service Contracts</strong></h6></li>
                <li ><h6><strong>Maintenance Contracts</strong></h6></li>
            </ul>
    <!-- repeater1 ends -->
</div>
</div>
<div>
<a><span id="imgDownArrow_0" class="glyphicon glyphicon-chevron-right " runat="server"> MoreInformation</span></a>
<div id="parent" class="dataContentSectionMessages" style="display:none">
    <!-- repeater1 starts -->
        <!-- <sc:text field="Event Description" runat="server" item="<%#Container.DataItem %>" /> -->
            <ul  >
                <li ><h6><strong>lorem</strong></h6></li>
                <li ><h6><strong>An assigned contact who knows you and your lorem analysis system</strong></h6></li>
                <li ><h6><strong>Internet accessible on-demand information and an easy to use internet shop</strong></h6></li>
                <li ><h6><strong>Extensive and flexible repair capabilities at any location</strong></h6></li>
                <li ><h6><strong>Full Service Contracts</strong></h6></li>
                <li ><h6><strong>Maintenance Contracts</strong></h6></li>
            </ul>
    <!-- repeater1 ends -->
</div>
</div>




</asp:Repeater>


</body>
<!-- Predefined JavaScript -->
<script src="jquery.js"></script>
<script src="bootstrap.js"></script>

<script>

 $(function () {
        $('a').click(function() {
            $(this).parent().children('.dataContentSectionMessages').slideToggle();
        });
    });

    </script>


</html>

jQuery append and remove dynamic table row

There are multiple problems here

  1. Id should be unique in a page
  2. For dynamic elements, you need to use event delegation using .on()

Ex

$(document).ready(function(){
    $("#addCF").click(function(){
        $("#customFields").append('<tr valign="top"><th scope="row"><label for="customFieldName">Custom Field</label></th><td><input type="text" class="code" id="customFieldName" name="customFieldName[]" value="" placeholder="Input Name" /> &nbsp; <input type="text" class="code" id="customFieldValue" name="customFieldValue[]" value="" placeholder="Input Value" /> &nbsp; <a href="javascript:void(0);" id="remCF">Remove</a></td></tr>');
    });

    $("#customFields").on('click', '#remCF', function(){
        $(this).parent().parent().remove();
    });

});

Demo: Fiddle

See this demo where id properties are removed.

$(document).ready(function(){
    $("#addCF").click(function(){
        $("#customFields").append('<tr valign="top"><th scope="row"><label for="customFieldName">Custom Field</label></th><td><input type="text" class="code" name="customFieldName[]" value="" placeholder="Input Name" /> &nbsp; <input type="text" class="code" name="customFieldValue[]" value="" placeholder="Input Value" /> &nbsp; <a href="javascript:void(0);" class="remCF">Remove</a></td></tr>');
    });

    $("#customFields").on('click', '.remCF', function(){
        $(this).parent().parent().remove();
    });

});

Jquery find nearest matching element

You could try:

$(this).closest(".column").prev().find(".inputQty").val();

Return different type of data from a method in java?

the approach you took is good. Just Implementation may need to be better. For instance ReturningValues should be well defined and Its better if you can make ReturningValues as immutable.

// this approach is better
public static ReturningValues myMethod() {
    ReturningValues rv = new ReturningValues("value", 12);
    return rv;
}


public final class ReturningValues {
    private final String value;
    private final int index;


    public ReturningValues(String value, int index) {
      this.value = value;
      this.index = index;
     }

} 

Or if you have lots of key value pairs you can use HashMap then

public static Map<String,Object> myMethod() {
  Map<String,Object> map = new HashMap<String,Object>();
  map.put(VALUE, "value");
  map.put(INDEX, 12);
  return Collections.unmodifiableMap(map); // try to use this 
}

Slide right to left Android Animations

You can do Your own Animation style as an xml file like this(put it in anim folder):

left to right:

  <set xmlns:android="http://schemas.android.com/apk/res/android"
     android:shareInterpolator="false">
        <translate android:fromXDelta="-100%" android:toXDelta="0%"
         android:fromYDelta="0%" android:toYDelta="0%"
         android:duration="500"/>
  </set>

right to left:

    <set xmlns:android="http://schemas.android.com/apk/res/android"
     android:shareInterpolator="false">
     <translate
        android:fromXDelta="0%" android:toXDelta="100%"
        android:fromYDelta="0%" android:toYDelta="0%"
        android:duration="500" />
   </set>

here You can set Your own values at duration, maybe it depends on the phone model how the animation will look like, try some values out if it looks not good.

and then You can call it in Your activity:

     Intent animActivity = new Intent(this,YourStartAfterAnimActivity.class);
      startActivity(nextActivity);

      overridePendingTransition(R.anim.your_left_to_right, R.anim.your_right_to_left);

Typescript interface default values

You can use the Partial mapped type as explained in the documentation: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-1.html

In your example, you'll have:

interface IX {
    a: string;
    b: any;
    c: AnotherType;
}

let x: Partial<IX> = {
    a: 'abc'
}

How can I fix assembly version conflicts with JSON.NET after updating NuGet package references in a new ASP.NET MVC 5 project?

Remember that with the binding redirection

oldVersion="0.0.0.0-6.0.0.0"

You are saying that the old versions of the dll are between version 0.0.0.0 and version 6.0.0.0.

How can I specify a local gem in my Gemfile?

If you want the branch too:

gem 'foo', path: "point/to/your/path", branch: "branch-name"

Cannot truncate table because it is being referenced by a FOREIGN KEY constraint?

truncate did not work for me, delete + reseed is the best way out. In case there are some of you out there who need to iterate over huge number of tables to perform delete + reseed, you might run into issues with some tables which does not have an identity column, the following code checks if identity column exist before attempting to reseed

    EXEC ('DELETE FROM [schemaName].[tableName]')
    IF EXISTS (Select * from sys.identity_columns where object_name(object_id) = 'tableName')
    BEGIN
        EXEC ('DBCC CHECKIDENT ([schemaName.tableName], RESEED, 0)')
    END

replacing NA's with 0's in R dataframe

dataset <- matrix(sample(c(NA, 1:5), 25, replace = TRUE), 5);
data <- as.data.frame(dataset)
[,1] [,2] [,3] [,4] [,5] 
[1,]    2    3    5    5    4
[2,]    2    4    3    2    4
[3,]    2   NA   NA   NA    2
[4,]    2    3   NA    5    5
[5,]    2    3    2    2    3
data[is.na(data)] <- 0

Which version of CodeIgniter am I currently using?

Yes, the constant CI_VERSION will give you the current CodeIgniter version number. It's defined in: /system/codeigniter/CodeIgniter.php As of CodeIgniter 2, it's defined in /system/core/CodeIgniter.php

For example,

echo CI_VERSION; // echoes something like 1.7.1

How do I tar a directory of files and folders without including the directory itself?

function tar.create() {
        local folder="${1}"
        
        local tar="$(basename "${folder}")".tar.gz
        
        cd "${folder}" && tar -zcvf "../${tar}" .; cd - &> /dev/null
}

Example:

tar.create /path/to/folder

You are welcome.

C# HttpWebRequest The underlying connection was closed: An unexpected error occurred on a send

I had similar issue and the below line helped me solving the issue.Thanks to rene. I just pasted this line above the authentication code and it worked

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

How to clear all data in a listBox?

What about

listbox1.Items.Clear();

angular.element vs document.getElementById or jQuery selector with spin (busy) control

Improvement to kaiser's answer:

var myEl = $document.find('#some-id');

Don't forget to inject $document into your directive

Cloud Firestore collection count

Took me a while to get this working based on some of the answers above, so I thought I'd share it for others to use. I hope it's useful.

'use strict';

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
const db = admin.firestore();

exports.countDocumentsChange = functions.firestore.document('library/{categoryId}/documents/{documentId}').onWrite((change, context) => {

    const categoryId = context.params.categoryId;
    const categoryRef = db.collection('library').doc(categoryId)
    let FieldValue = require('firebase-admin').firestore.FieldValue;

    if (!change.before.exists) {

        // new document created : add one to count
        categoryRef.update({numberOfDocs: FieldValue.increment(1)});
        console.log("%s numberOfDocs incremented by 1", categoryId);

    } else if (change.before.exists && change.after.exists) {

        // updating existing document : Do nothing

    } else if (!change.after.exists) {

        // deleting document : subtract one from count
        categoryRef.update({numberOfDocs: FieldValue.increment(-1)});
        console.log("%s numberOfDocs decremented by 1", categoryId);

    }

    return 0;
});

System.Drawing.Image to stream C#

Use a memory stream

using(MemoryStream ms = new MemoryStream())
{
    image.Save(ms, ...);
    return ms.ToArray();
}

How to set focus on input field?

Here is my original solution:

plunker

var app = angular.module('plunker', []);
app.directive('autoFocus', function($timeout) {
    return {
        link: function (scope, element, attrs) {
            attrs.$observe("autoFocus", function(newValue){
                if (newValue === "true")
                    $timeout(function(){element[0].focus()});
            });
        }
    };
});

And the HTML:

<button ng-click="isVisible = !isVisible">Toggle input</button>
<input ng-show="isVisible" auto-focus="{{ isVisible }}" value="auto-focus on" />

What it does:

It focuses the input as it becomes visible with ng-show. No use of $watch or $on here.

When does a cookie with expiration time 'At end of session' expire?

When you use setcookie, you can either set the expiration time to 0 or simply omit the parametre - the cookie will then expire at the end of session (ie, when you close the browser).

How to make remote REST call inside Node.js? any CURL?

I have been using restler for making webservices call, works like charm and is pretty neat.

How to restart Postgresql

Try this as root (maybe you can use sudo or su):

/etc/init.d/postgresql restart

Without any argument the script also gives you a hint on how to restart a specific version

[Uqbar@Feynman ~] /etc/init.d/postgresql
Usage: /etc/init.d/postgresql {start|stop|restart|reload|force-reload|status} [version ...]

Similarly, in case you have it, you can also use the service tool:

[Uqbar@Feynman ~] service postgresql
Usage: /etc/init.d/postgresql {start|stop|restart|reload|force reload|status} [version ...]

Please, pay attention to the optional [version ...] trailing argument. That's meant to allow you, the user, to act on a specific version, in case you were running multiple ones. So you can restart version X while keeping version Y and Z untouched and running.

Finally, in case you are running systemd, then you can use systemctl like this:

[support@Feynman ~] systemctl status postgresql
? postgresql.service - PostgreSQL database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql.service; enabled; vendor preset: disabled)
   Active: active (running) since Wed 2017-11-14 12:33:35 CET; 7min ago
...

You can replace status with stop, start or restart as well as other actions. Please refer to the documentation for full details. In order to operate on multiple concurrent versions, the syntax is slightly different. For example to stop v12 and reload v13 you can run:

systemctl stop postgresql-12.service
systemctl reload postgresql-13.service

Thanks to @Jojo for pointing me to this very one. Finally Keep in mind that root permissions may be needed for non-informative tasks as in the other cases seen earlier.

Call to a member function on a non-object

Either $objPage is not an instance variable OR your are overwriting $objPage with something that is not an instance of class PageAttributes.

Pandas groupby: How to get a union of strings

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

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

Default Values to Stored Procedure in Oracle

Default-Values are only considered for parameters NOT given to the function.

So given a function

procedure foo( bar1 IN number DEFAULT 3,
     bar2 IN number DEFAULT 5,
     bar3 IN number DEFAULT 8 );

if you call this procedure with no arguments then it will behave as if called with

foo( bar1 => 3,
     bar2 => 5,
     bar3 => 8 );

but 'NULL' is still a parameter.

foo( 4,
     bar3 => NULL );

This will then act like

foo( bar1 => 4,
     bar2 => 5,
     bar3 => Null );

( oracle allows you to either give the parameter in order they are specified in the procedure, specified by name, or first in order and then by name )

one way to treat NULL the same as a default value would be to default the value to NULL

procedure foo( bar1 IN number DEFAULT NULL,
     bar2 IN number DEFAULT NULL,
     bar3 IN number DEFAULT NULL );

and using a variable with the desired value then

procedure foo( bar1 IN number DEFAULT NULL,
     bar2 IN number DEFAULT NULL,
     bar3 IN number DEFAULT NULL )
AS
     v_bar1    number := NVL( bar1, 3);
     v_bar2    number := NVL( bar2, 5);
     v_bar3    number := NVL( bar3, 8);

sqlite3.ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 74 supplied

cursor.execute(sql,array)

Only takes two arguments.
It will iterate the "array"-object and match ? in the sql-string.
(with sanity checks to avoid sql-injection)

Cleanest way to build an SQL string in Java

I am wondering if you are after something like Squiggle. Also something very useful is jDBI. It won't help you with the queries though.

using scp in terminal

Simple :::

scp remoteusername@remoteIP:/path/of/file /Local/path/to/copy

scp -r remoteusername@remoteIP:/path/of/folder /Local/path/to/copy

jQuery text() and newlines

It's the year 2015. The correct answer to this question at this point is to use CSS white-space: pre-line or white-space: pre-wrap. Clean and elegant. The lowest version of IE that supports the pair is 8.

https://css-tricks.com/almanac/properties/w/whitespace/

P.S. Until CSS3 become common you'd probably need to manually trim off initial and/or trailing white-spaces.

How to run test methods in specific order in JUnit4?

I ended up here thinking that my tests weren't run in order, but the truth is that the mess was in my async jobs. When working with concurrency you need to perform concurrency checks between your tests as well. In my case, jobs and tests share a semaphore, so next tests hang until the running job releases the lock.

I know this is not fully related to this question, but maybe could help targeting the correct issue

SVG rounded corner

This question is the first result for Googling "svg rounded corners path". Phrogz suggestion to use stroke has some limitations (namely, that I cannot use stroke for other purposes, and that the dimensions have to be corrected for the stroke width).

Jlange suggestion to use a curve is better, but not very concrete. I ended up using quadratic Bézier curves for drawing rounded corners. Consider this picture of a corner marked with a blue dot and two red points on adjacent edges:

corner of a figure marked blue with two points on the adjacent edges

The two lines could be made with the L command. To turn this sharp corner into a rounded corner, start drawing a curve from the left red point (use M x,y to move to that point). Now a quadratic Bézier curve has just a single control point which you must set on the blue point. Set the end of the curve at the right red point. As the tangent at the two red points are in the direction of the previous lines, you will see a fluent transition, "rounded corners".

Now to continue the shape after the rounded corner, a straight line in a Bézier curve can be achieved by setting the control point between on the line between the two corners.

To help me with determining the path, I wrote this Python script that accepts edges and a radius. Vector math makes this actually very easy. The resulting image from the output:

shape created from script output

#!/usr/bin/env python
# Given some vectors and a border-radius, output a SVG path with rounded
# corners.
#
# Copyright (C) Peter Wu <[email protected]>

from math import sqrt

class Vector(object):
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def sub(self, vec):
        return Vector(self.x - vec.x, self.y - vec.y)

    def add(self, vec):
        return Vector(self.x + vec.x, self.y + vec.y)

    def scale(self, n):
        return Vector(self.x * n, self.y * n)

    def length(self):
        return sqrt(self.x**2 + self.y**2)

    def normal(self):
        length = self.length()
        return Vector(self.x / length, self.y / length)

    def __str__(self):
        x = round(self.x, 2)
        y = round(self.y, 2)
        return '{},{}'.format(x, y)

# A line from vec_from to vec_to
def line(vec_from, vec_to):
    half_vec = vec_from.add(vec_to.sub(vec_from).scale(.5))
    return '{} {}'.format(half_vec, vec_to)

# Adds 'n' units to vec_from pointing in direction vec_to
def vecDir(vec_from, vec_to, n):
    return vec_from.add(vec_to.sub(vec_from).normal().scale(n))

# Draws a line, but skips 'r' units from the begin and end
def lineR(vec_from, vec_to, r):
    vec = vec_to.sub(vec_from).normal().scale(r)
    return line(vec_from.add(vec), vec_to.sub(vec))

# An edge in vec_from, to vec_to with radius r
def edge(vec_from, vec_to, r):
    v = vecDir(vec_from, vec_to, r)
    return '{} {}'.format(vec_from, v)


# Hard-coded border-radius and vectors
r = 5
a = Vector(  0,  60)
b = Vector(100,   0)
c = Vector(100, 200)
d = Vector(  0, 200 - 60)

path = []
# Start below top-left edge
path.append('M {} Q'.format(a.add(Vector(0, r))))

# top-left edge...
path.append(edge(a, b, r))
path.append(lineR(a, b, r))
path.append(edge(b, c, r))
path.append(lineR(b, c, r))
path.append(edge(c, d, r))
path.append(lineR(c, d, r))
path.append(edge(d, a, r))
path.append(lineR(d, a, r))

# Show results that can be pushed into a <path d="..." />
for part in path:
    print(part)

Using Position Relative/Absolute within a TD?

With regards to your second attempt, did you try using vertical align ? Either

<td valign="bottom">

or with css

vertical-align:bottom

How to round up a number in Javascript?

parseInt always rounds down soo.....

_x000D_
_x000D_
console.log(parseInt(5.8)+1);
_x000D_
_x000D_
_x000D_

do parseInt()+1

Install a module using pip for specific python version

Alternatively, since pip itself is written in python, you can just call it with the python version you want to install the package for:

python2.7 -m pip install foo

error: package com.android.annotations does not exist

Open gradle.properties and use following code:

android.useAndroidX=false
android.enableJetifier=false

or U can use these dependencies too:

implementation 'androidx.appcompat:appcompat:1.0.2'
 implementation 'androidx.annotation:annotation:1.0.2'

Fastest way to update 120 Million records

What I'd try first is
to drop all constraints, indexes, triggers and full text indexes first before you update.

If above wasn't performant enough, my next move would be
to create a CSV file with 12 million records and bulk import it using bcp.

Lastly, I'd create a new heap table (meaning table with no primary key) with no indexes on a different filegroup, populate it with -1. Partition the old table, and add the new partition using "switch".

Recursively list files in Java

base on @Michael answer, add check whether listFiles return null

static Stream<File> files(File file) {
    return file.isDirectory()
            ? Optional.ofNullable(file.listFiles()).map(Stream::of).orElseGet(Stream::empty).flatMap(MainActivity::files)
            : Stream.of(file);
}

or use Lightweight-Stream-API, which support Android5 & Android6

static Stream<File> files(File f) {
    return f.isDirectory() ? Stream.ofNullable(f.listFiles()).flatMap(MainActivity::files) : Stream.of(f);
}

Difference between natural join and inner join

  • An inner join is one where the matching row in the joined table is required for a row from the first table to be returned
  • An outer join is one where the matching row in the joined table is not required for a row from the first table to be returned
  • A natural join is a join (you can have either natural left or natural right) that assumes the join criteria to be where same-named columns in both table match

I would avoid using natural joins like the plague, because natural joins are:

  • not standard sql [SQL 92] and therefore not portable, not particularly readable (by most SQL coders) and possibly not supported by various tools/libraries
  • not informative; you can't tell what columns are being joined on without referring to the schema
  • your join conditions are invisibly vulnerable to schema changes - if there are multiple natural join columns and one such column is removed from a table, the query will still execute, but probably not correctly and this change in behaviour will be silent
  • hardly worth the effort; you're only saving about 10 seconds of typing

How to prevent form resubmission when page is refreshed (F5 / CTRL+R)

I searched for solution to prevent resubmission in a huge project afterwards. The code highly works with $_GET and $_POST and I can't change the form elements behaviour without the risk of unforeseen bugs. So, here is my code:

<!-- language: lang-php -->
<?php

// Very top of your code:

// Start session:
session_start();

// If Post Form Data send and no File Upload
if ( empty( $_FILES ) && ! empty( $_POST ) ) {
    // Store Post Form Data in Session Variable
    $_SESSION["POST"] = $_POST;
    // Reload Page if there were no outputs
    if ( ! headers_sent() ) {
        // Build URL to reload with GET Parameters
        // Change https to http if your site has no ssl
        $location = "https://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
        // Reload Page
        header( "location: " . $location, true, 303 );
        // Stop any further progress
        die();
    }
}

// Rebuilt POST Form Data from Session Variable
if ( isset( $_SESSION["POST"] ) ) {
    $_POST = $_SESSION["POST"];
    // Tell PHP that POST is sent
    $_SERVER['REQUEST_METHOD'] = 'POST';
}

// Your code:
?><html>
    <head>
        <title>GET/POST Resubmit</title>
    </head>
    <body>

    <h1>Forms:</h1>
    <h2>GET Form:</h2>
    <form action="index.php" method="get">
        <input type="text" id="text_get" value="test text get" name="text_get"/>
        <input type="submit" value="submit">
    </form>
    <h2>POST Form:</h2>
    <form action="index.php" method="post">
        <input type="text" id="text_post" value="test text post" name="text_post"/>
        <input type="submit" value="submit">
    </form>
    <h2>POST Form with GET action:</h2>
    <form action="index.php?text_get2=getwithpost" method="post">
        <input type="text" id="text_post2" value="test text get post" name="text_post2"/>
        <input type="submit" value="submit">
    </form>
    <h2>File Upload Form:</h2>
    <form action="index.php" method="post" enctype="multipart/form-data">
        <input type="file" id="file" name="file">
        <input type="submit" value="submit">
    </form>

    <h1>Results:</h1>
    <h2>GET Form Result:</h2>
    <p>text_get: <?php echo $_GET["text_get"]; ?></p>
    <h2>POST Form Result:</h2>
    <p>text_post: <?php echo $_POST["text_post"]; ?></p>
    <h2>POST Form with GET Result:</h2>
    <p>text_get2: <?php echo $_GET["text_get2"]; ?></p>
    <p>text_post2: <?php echo $_POST["text_post2"]; ?></p>
    <h2>File Upload:</h2>
    <p>file:
    <pre><?php if ( ! empty( $_FILES ) ) {
            echo print_r( $_FILES, true );
        } ?></pre>
    </p>
    <p></p>
    </body>
    </html><?php
// Very Bottom of your code:
// Kill Post Form Data Session Variable, so User can reload the Page without sending post data twice
unset( $_SESSION["POST"] );

It only works to avoid the resubmit of $_POST, not $_GET. But this is the behaviour I need. The resubmit issue doesn't work with file uploads!

Working with TIFFs (import, export) in Python using numpy

I use matplotlib for reading TIFF files:

import matplotlib.pyplot as plt
I = plt.imread(tiff_file)

and I will be of type ndarray.

According to the documentation though it is actually PIL that works behind the scenes when handling TIFFs as matplotlib only reads PNGs natively, but this has been working fine for me.

There's also a plt.imsave function for saving.

Why does instanceof return false for some literals?

You can use constructor property:

'foo'.constructor == String // returns true
true.constructor == Boolean // returns true

When to use: Java 8+ interface default method, vs. abstract method

Default methods in Java interface enables interface evolution.

Given an existing interface, if you wish to add a method to it without breaking the binary compatibility with older versions of the interface, you have two options at hands: add a default or a static method. Indeed, any abstract method added to the interface would have to be impleted by the classes or interfaces implementing this interface.

A static method is unique to a class. A default method is unique to an instance of the class.

If you add a default method to an existing interface, classes and interfaces which implement this interface do not need to implement it. They can

  • implement the default method, and it overrides the implementation in implemented interface.
  • re-declare the method (without implementation) which makes it abstract.
  • do nothing (then the default method from implemented interface is simply inherited).

More on the topic here.

How can I show a hidden div when a select option is selected?

You should hook onto the change event of the <select> element instead of on the individual options.

var select = document.getElementById('test'),
onChange = function(event) {
    var shown = this.options[this.selectedIndex].value == 1;

    document.getElementById('hidden_div').style.display = shown ? 'block' : 'none';
};

// attach event handler
if (window.addEventListener) {
    select.addEventListener('change', onChange, false);
} else {
    // of course, IE < 9 needs special treatment
    select.attachEvent('onchange', function() {
        onChange.apply(select, arguments);
    });
}

Demo

How to convert a structure to a byte array in C#?

Have a look at these methods:

byte [] StructureToByteArray(object obj)
{
    int len = Marshal.SizeOf(obj);

    byte [] arr = new byte[len];

    IntPtr ptr = Marshal.AllocHGlobal(len);

    Marshal.StructureToPtr(obj, ptr, true);

    Marshal.Copy(ptr, arr, 0, len);

    Marshal.FreeHGlobal(ptr);

    return arr;
}

void ByteArrayToStructure(byte [] bytearray, ref object obj)
{
    int len = Marshal.SizeOf(obj);

    IntPtr i = Marshal.AllocHGlobal(len);

    Marshal.Copy(bytearray,0, i,len);

    obj = Marshal.PtrToStructure(i, obj.GetType());

    Marshal.FreeHGlobal(i);
}

This is a shameless copy of another thread which I found upon Googling!

Update : For more details, check the source

What does \u003C mean?

Those are unicode escapes. The general unicode escapes looks like \uxxxx where xxxx are the hexadecimal digits of the ASCI characters. They are used mainly to insert special characters inside a javascript string.

How to know what the 'errno' means?

Call

perror("execl");

in case of error.

Sample:

if(read(fd, buf, 1)==-1) {
    perror("read");
}

The manpages of errno(3) and perror(3) are interesting, too...

Column/Vertical selection with Keyboard in SublimeText 3

The reason why the sublime documented shortcuts for Mac does not work are they are linked to the shortcuts of other Mac functionalities such as Mission Control, Application Windows, etc. Solution: Go to System Preferences -> Keyboard -> Shortcuts and then un-check the options for Mission Control and Application Windows. Now try "Control + Shift [+ Arrow keys]" for selecting the required text and then move the cursor to the required location without any mouse click, so that the selection can be pasted with the correct indentation at the required location.

php REQUEST_URI

I think that parse_str is what you're looking for, something like this should do the trick for you:

parse_str($_SERVER['QUERY_STRING'], $vars);

Then the $vars array will hold all the passed arguments.

PHP, getting variable from another php-file

You could also use a session for passing small bits of info. You will need to have session_start(); at the top of the PHP pages that use the session else the variables will not be accessable

page1.php

<?php

   session_start();
   $_SESSION['superhero'] = "batman";

?>
<a href="page2.php" title="">Go to the other page</a>

page2.php

<?php 

   session_start(); // this NEEDS TO BE AT THE TOP of the page before any output etc
   echo $_SESSION['superhero'];

?>

How to change lowercase chars to uppercase using the 'keyup' event?

I work with telerik radcontrols that's why I Find a control, but you can find control directly like: $('#IdExample').css({

this code works for me, I hope help you and sorry my english.

Code Javascript:

<script type="javascript"> 
function changeToUpperCase(event, obj) {
var txtDescripcion = $("#%=RadPanelBar1.Items(0).Items(0).FindControl("txtDescripcion").ClientID%>");
             txtDescripcion.css({
                 "text-transform": "uppercase"
             });
} </script>

Code ASP.NET

<asp:TextBox ID="txtDescripcion" runat="server" MaxLength="80" Width="500px"                                                             onkeypress="return changeToUpperCase(event,this)"></asp:TextBox>

Scroll back to the top of scrollable div

This worked for me :

document.getElementById('yourDivID').scrollIntoView();

Javascript change Div style

Using jQuery:

$(document).ready(function(){
    $('div').click(function(){
        $(this).toggleClass('clicked');
    });
});?

Live example

Using Spring RestTemplate in generic method with generic parameter

No, it is not a bug. It is a result of how the ParameterizedTypeReference hack works.

If you look at its implementation, it uses Class#getGenericSuperclass() which states

Returns the Type representing the direct superclass of the entity (class, interface, primitive type or void) represented by this Class.

If the superclass is a parameterized type, the Type object returned must accurately reflect the actual type parameters used in the source code.

So, if you use

new ParameterizedTypeReference<ResponseWrapper<MyClass>>() {}

it will accurately return a Type for ResponseWrapper<MyClass>.

If you use

new ParameterizedTypeReference<ResponseWrapper<T>>() {}

it will accurately return a Type for ResponseWrapper<T> because that is how it appears in the source code.

When Spring sees T, which is actually a TypeVariable object, it doesn't know the type to use, so it uses its default.

You cannot use ParameterizedTypeReference the way you are proposing, making it generic in the sense of accepting any type. Consider writing a Map with key Class mapped to a predefined ParameterizedTypeReference for that class.

You can subclass ParameterizedTypeReference and override its getType method to return an appropriately created ParameterizedType, as suggested by IonSpin.

How to write multiple conditions in Makefile.am with "else if"

ifeq ($(CHIPSET),8960)
   BLD_ENV_BUILD_ID="8960"
else ifeq ($(CHIPSET),8930)
   BLD_ENV_BUILD_ID="8930"
else ifeq ($(CHIPSET),8064)
   BLD_ENV_BUILD_ID="8064"
else ifeq ($(CHIPSET), 9x15)
   BLD_ENV_BUILD_ID="9615"
else
   BLD_ENV_BUILD_ID=
endif

Subtracting 1 day from a timestamp date

Use the INTERVAL type to it. E.g:

--yesterday
SELECT NOW() - INTERVAL '1 DAY';

--Unrelated to the question, but PostgreSQL also supports some shortcuts:
SELECT 'yesterday'::TIMESTAMP, 'tomorrow'::TIMESTAMP, 'allballs'::TIME;

Then you can do the following on your query:

SELECT 
    org_id,
    count(accounts) AS COUNT,
    ((date_at) - INTERVAL '1 DAY') AS dateat
FROM 
    sourcetable
WHERE 
    date_at <= now() - INTERVAL '130 DAYS'
GROUP BY 
    org_id,
    dateat;


TIPS

Tip 1

You can append multiple operands. E.g.: how to get last day of current month?

SELECT date_trunc('MONTH', CURRENT_DATE) + INTERVAL '1 MONTH - 1 DAY';

Tip 2

You can also create an interval using make_interval function, useful when you need to create it at runtime (not using literals):

SELECT make_interval(days => 10 + 2);
SELECT make_interval(days => 1, hours => 2);
SELECT make_interval(0, 1, 0, 5, 0, 0, 0.0);


More info:

Date/Time Functions and Operators

datatype-datetime (Especial values).

Access parent DataContext from DataTemplate

I was searching how to do something similar in WPF and I got this solution:

<ItemsControl ItemsSource="{Binding MyItems,Mode=OneWay}">
<ItemsControl.ItemsPanel>
    <ItemsPanelTemplate>
        <StackPanel Orientation="Vertical" />
    </ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
    <DataTemplate>
        <RadioButton 
            Content="{Binding}" 
            Command="{Binding Path=DataContext.CustomCommand, 
                        RelativeSource={RelativeSource Mode=FindAncestor,      
                        AncestorType={x:Type ItemsControl}} }"
            CommandParameter="{Binding}" />
    </DataTemplate>
</ItemsControl.ItemTemplate>

I hope this works for somebody else. I have a data context which is set automatically to the ItemsControls, and this data context has two properties: MyItems -which is a collection-, and one command 'CustomCommand'. Because of the ItemTemplate is using a DataTemplate, the DataContext of upper levels is not directly accessible. Then the workaround to get the DC of the parent is use a relative path and filter by ItemsControl type.

how to fix EXE4J_JAVA_HOME, No JVM could be found on your system error?

There are few steps to overcome this problem:

  1. Uninstall Java related softwares
  2. Uninstall NodeJS if installed
  3. Download java 8 update161
  4. Install it

The problem solved: The problem raised to me at the uninstallation on openfire server.

How do I put my website's logo to be the icon image in browser tabs?

That image is called 'favicon' and it's a small square shaped .ico file, which is the standard file type for favicons. You could use .png or .gif too, but you should follow the standard for better compatibility.

To set one for your website you should:

  1. Make a square image of your logo (preferably 32x32 or 16x16 pixels, as far as I know there's no max size*), and transform it into an .ico file. You can do this on Gimp, Photoshop (with help of a plugin) or a website like Favicon.cc or RealFaviconGenerator.

  2. Then, you have two ways of setting it up:

    A) Placing it on the root folder/directory of your website (next to index.html) with the name favicon.ico.

    or

    B) Link to it between the <head></head> tags of every .html file on your site, like this:

    <head>
      <link rel="shortcut icon" type="image/x-icon" href="favicon.ico" />
    </head>
    

If you want to see the favicon from any website, just write www.url.com/favicon.ico and you'll (probably) see it. Stackoverflow's favicon is 16x16 pixels and Wikipedia is 32x32.

*: There's even a browser problem with no filesize limit. You could easily crash a browser with an exceedingly large favicon, more info here

R - " missing value where TRUE/FALSE needed "

Can you change the if condition to this:

if (!is.na(comments[l])) print(comments[l]);

You can only check for NA values with is.na().

How to handle an IF STATEMENT in a Mustache template?

Mustache templates are, by design, very simple; the homepage even says:

Logic-less templates.

So the general approach is to do your logic in JavaScript and set a bunch of flags:

if(notified_type == "Friendship")
    data.type_friendship = true;
else if(notified_type == "Other" && action == "invite")
    data.type_other_invite = true;
//...

and then in your template:

{{#type_friendship}}
    friendship...
{{/type_friendship}}
{{#type_other_invite}}
    invite...
{{/type_other_invite}}

If you want some more advanced functionality but want to maintain most of Mustache's simplicity, you could look at Handlebars:

Handlebars provides the power necessary to let you build semantic templates effectively with no frustration.

Mustache templates are compatible with Handlebars, so you can take a Mustache template, import it into Handlebars, and start taking advantage of the extra Handlebars features.

Twitter Bootstrap - full width navbar

You can override some css

body {
    padding-left: 0px !important;
    padding-right: 0px !important;
}

.navbar-inner {
    border-radius: 0px !important;
}

The !important is needed just in case you link the bootstrap.css after your custom css.

And add your nav html out of a .container

Lotus Notes email as an attachment to another email

I have been trying to do this for a while also. Here is what I do now. Highlight the email you want to create as a file. Click on Create. Hover over Special, then click on Link message. This will open up a new tab for the link. At the bottom of the message is a small yellow piece of paper icon. Copy this icon and paste into your message like you would any other file. It is tiny, so I put a statement like "see email attachment ---->" in front of the icon. You might like this way. Not sure though.

Count number of iterations in a foreach loop

You can do sizeof($Contents) or count($Contents)

also this

$count = 0;
foreach($Contents as $items) {
  $count++;
  $items[number];
}

How do I determine if a port is open on a Windows server?

Assuming that it's a TCP (rather than UDP) port that you're trying to use:

  1. On the server itself, use netstat -an to check to see which ports are listening.

  2. From outside, just use telnet host port (or telnet host:port on Unix systems) to see if the connection is refused, accepted, or timeouts.

On that latter test, then in general:

  • connection refused means that nothing is running on that port
  • accepted means that something is running on that port
  • timeout means that a firewall is blocking access

On Windows 7 or Windows Vista the default option 'telnet' is not recognized as an internal or external command, operable program or batch file. To solve this, just enable it: Click *Start** → Control PanelProgramsTurn Windows Features on or off. In the list, scroll down and select Telnet Client and click OK.

Finding index of character in Swift String

This worked for me,

var loc = "abcdefghi".rangeOfString("c").location
NSLog("%d", loc);

this worked too,

var myRange: NSRange = "abcdefghi".rangeOfString("c")
var loc = myRange.location
NSLog("%d", loc);

Open a local HTML file using window.open in Chrome

This worked for me fine:

File 1:

    <html>
    <head></head>
    <body>
        <a href="#" onclick="window.open('file:///D:/Examples/file2.html'); return false">CLICK ME</a>
    </body>
    <footer></footer>
    </html>

File 2:

    <html>
        ...
    </html>

This method works regardless of whether or not the 2 files are in the same directory, BUT both files must be local.

For obvious security reasons, if File 1 is located on a remote server you absolutely cannot open a file on some client's host computer and trying to do so will open a blank target.

How do you count the lines of code in a Visual Studio solution?

Agree with Ali Parr. The WndTab Line Counter addin is a such tool. http://www.codeproject.com/KB/macros/linecount.aspx

It's also a good idea to search from download site to find some related tool. http://www.cnet.com/1770-5_1-0.html?query=code+counter&tag=srch

websocket.send() parameter

As I understand it, you want the server be able to send messages through from client 1 to client 2. You cannot directly connect two clients because one of the two ends of a WebSocket connection needs to be a server.

This is some pseudocodish JavaScript:

Client:

var websocket = new WebSocket("server address");

websocket.onmessage = function(str) {
  console.log("Someone sent: ", str);
};

// Tell the server this is client 1 (swap for client 2 of course)
websocket.send(JSON.stringify({
  id: "client1"
}));

// Tell the server we want to send something to the other client
websocket.send(JSON.stringify({
  to: "client2",
  data: "foo"
}));

Server:

var clients = {};

server.on("data", function(client, str) {
  var obj = JSON.parse(str);

  if("id" in obj) {
    // New client, add it to the id/client object
    clients[obj.id] = client;
  } else {
    // Send data to the client requested
    clients[obj.to].send(obj.data);
  }
});

How to query between two dates using Laravel and Eloquent?

I know this might be an old question but I just found myself in a situation where I had to implement this feature in a Laravel 5.7 app. Below is what worked from me.

 $articles = Articles::where("created_at",">", Carbon::now()->subMonths(3))->get();

You will also need to use Carbon

use Carbon\Carbon;

SQlite - Android - Foreign key syntax

You have to define your TASK_CAT column first and then set foreign key on it.

private static final String TASK_TABLE_CREATE = "create table "
        + TASK_TABLE + " (" 
        + TASK_ID + " integer primary key autoincrement, " 
        + TASK_TITLE + " text not null, " 
        + TASK_NOTES + " text not null, "
        + TASK_DATE_TIME + " text not null,"
        + TASK_CAT + " integer,"
        + " FOREIGN KEY ("+TASK_CAT+") REFERENCES "+CAT_TABLE+"("+CAT_ID+"));";

More information you can find on sqlite foreign keys doc.

Simple way to check if a string contains another string in C?

if (strstr(request, "favicon") != NULL) {
    // contains
}

Delete a single record from Entity Framework?

I am using entity framework with LINQ. Following code was helpful for me;

1- For multiple records

 using (var dbContext = new Chat_ServerEntities())
 {
     var allRec= dbContext.myEntities;
     dbContext.myEntities.RemoveRange(allRec);
     dbContext.SaveChanges();
 }

2- For Single record

 using (var dbContext = new Chat_ServerEntities())
 {
     var singleRec = dbContext.ChatUserConnections.FirstOrDefault( x => x.ID ==1);// object your want to delete
     dbContext.ChatUserConnections.Remove(singleRec);
     dbContext.SaveChanges();
 }

What is the difference between C# and .NET?

C# does not have a seperate runtime library. It uses .NET as a runtime library.

regex pattern to match the end of a string

Something like this should work: /([^/]*)$

What language are you using? End-of-string regex signifiers can vary in different languages.

How do I copy a folder from remote to local using scp?

I don't know why but I was had to use local folder before source server directive . to make it work

scp -r . [email protected]:/usr/share/nginx/www/example.org/

How do I call REST API from an android app?

  1. If you want to integrate Retrofit (all steps defined here):

Goto my blog : retrofit with kotlin

  1. Please use android-async-http library.

the link below explains everything step by step.

http://loopj.com/android-async-http/

Here are sample apps:

  1. http://www.techrepublic.com/blog/software-engineer/calling-restful-services-from-your-android-app/

  2. http://blog.strikeiron.com/bid/73189/Integrate-a-REST-API-into-Android-Application-in-less-than-15-minutes

Create a class :

public class HttpUtils {
  private static final String BASE_URL = "http://api.twitter.com/1/";
 
  private static AsyncHttpClient client = new AsyncHttpClient();

  public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.get(getAbsoluteUrl(url), params, responseHandler);
  }

  public static void post(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.post(getAbsoluteUrl(url), params, responseHandler);
  }
      
  public static void getByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.get(url, params, responseHandler);
  }

  public static void postByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.post(url, params, responseHandler);
  }

  private static String getAbsoluteUrl(String relativeUrl) {
      return BASE_URL + relativeUrl;
  }
}

Call Method :

    RequestParams rp = new RequestParams();
    rp.add("username", "aaa"); rp.add("password", "aaa@123");
                    
    HttpUtils.post(AppConstant.URL_FEED, rp, new JsonHttpResponseHandler() {
        @Override
        public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
            // If the response is JSONObject instead of expected JSONArray
            Log.d("asd", "---------------- this is response : " + response);
            try {
                JSONObject serverResp = new JSONObject(response.toString());                                                
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }                   
        }
            
        @Override
        public void onSuccess(int statusCode, Header[] headers, JSONArray timeline) {
            // Pull out the first event on the public timeline
                    
        }
    });

Please grant internet permission in your manifest file.

 <uses-permission android:name="android.permission.INTERNET" />

you can add compile 'com.loopj.android:android-async-http:1.4.9' for Header[] and compile 'org.json:json:20160212' for JSONObject in build.gradle file if required.

How to increment variable under DOS?

A little bit late for the party, but it's an interessting question.

You can write your own inc.bat for incrementing a number.
It can increment numbers from 0 to 9998.

@echo off
if "%1"==":inc" goto :increment

call %0 :inc %counter0%
set counter0=%_cnt%
if %_overflow%==0 goto :exit 

call %0 :inc %counter1%
set counter1=%_cnt%
if %_overflow%==0 goto :exit 

call %0 :inc %counter2%
set counter2=%_cnt%
if %_overflow%==0 goto :exit 

call %0 :inc %counter3%
set counter3=%_cnt%
goto :exit

:increment
set _overflow=0
set _cnt=%2

if "%_cnt%"=="" set _cnt=0

if %_cnt%==9 goto :overflow
if %_cnt%==8 set _cnt=9
if %_cnt%==7 set _cnt=8
if %_cnt%==6 set _cnt=7
if %_cnt%==5 set _cnt=6
if %_cnt%==4 set _cnt=5
if %_cnt%==3 set _cnt=4
if %_cnt%==2 set _cnt=3
if %_cnt%==1 set _cnt=2
if %_cnt%==0 set _cnt=1
goto :exit

:overflow
set _cnt=0
set _overflow=1
goto :exit

:exit
set count=%counter3%%counter2%%counter1%%counter0%

A sample for using it is here

@echo off
set counter0=0
set counter1=
set counter2=
set counter3=

:loop
call inc.bat
echo %count%
if not %count%==250 goto :loop

How do you represent a JSON array of strings?

Basically yes, JSON is just a javascript literal representation of your value so what you said is correct.

You can find a pretty clear and good explanation of JSON notation on http://json.org/

How to format a date using ng-model?

In Angular2+ for anyone interested:

<input type="text" placeholder="My Date" [ngModel]="myDate | date: 'longDate'">

with type of filters in DatePipe Angular.

How to efficiently check if variable is Array or Object (in NodeJS & V8)?

looking at jQuery they in there jQuery.isArray(...) they do:

    isArray = Array.isArray || function( obj ) {
    return jQuery.type(obj) === "array";
}

this leads us to: jQuery.type:

    type = function( obj ) {
    return obj == null ?
        String( obj ) :
        class2type[ toString.call(obj) ] || "object";
}

and again we have to look in: class2type

class2type = {};

// Populate the class2type map
jQuery.each("Boolean Number String Function Array Date RegExp Object".split(" "), function(i, name) {
    class2type[ "[object " + name + "]" ] = name.toLowerCase();
});

and in native JS:

var a, t = "Boolean Number String Function Array Date RegExp Object".split(" ");
for( a in t ) {
    class2type[ "[object " + t[a] + "]" ] = t[a].toLowerCase();
}

this ends up with:

var isArray = Array.isArray || function( obj ) {
    return toString.call(obj) === "[object Array]";
}

Determine if Android app is being used for the first time

I like to have an "update count" in my shared preferences. If it's not there (or default zero value) then this is my app's "first use".

private static final int UPDATE_COUNT = 1;    // Increment this on major change
...
if (sp.getInt("updateCount", 0) == 0) {
    // first use
} else if (sp.getInt("updateCount", 0) < UPDATE_COUNT) {
    // Pop up dialog telling user about new features
}
...
sp.edit().putInt("updateCount", UPDATE_COUNT);

So now, whenever there's an update to the app that users should know about, I increment UPDATE_COUNT

How to delay the .keyup() handler until the user stops typing?

I'm surprised that nobody mention the problem with multiple input in CMS's very nice snipped.

Basically, you would have to define delay variable individually for each input. Otherwise if sb put text to first input and quickly jump to other input and start typing, callback for the first one WON'T be called!

See the code below I came with based on other answers:

(function($) {
    /**
     * KeyUp with delay event setup
     * 
     * @link http://stackoverflow.com/questions/1909441/jquery-keyup-delay#answer-12581187
     * @param function callback
     * @param int ms
     */
    $.fn.delayKeyup = function(callback, ms){
            $(this).keyup(function( event ){
                var srcEl = event.currentTarget;
                if( srcEl.delayTimer )
                    clearTimeout (srcEl.delayTimer );
                srcEl.delayTimer = setTimeout(function(){ callback( $(srcEl) ); }, ms);
            });

        return $(this);
    };
})(jQuery);

This solution keeps setTimeout reference within input's delayTimer variable. It also passes reference of element to callback as fazzyx suggested.

Tested in IE6, 8(comp - 7), 8 and Opera 12.11.

How to validate an email address in JavaScript

     // Html form call function name at submit button

    <form name="form1" action="#"> 
    <input type='text' name='text1'/>
    <input type="submit" name="submit" value="Submit" 
    onclick="ValidateEmail(document.form1.text1)"/>
   </from>

    // Write the function name ValidateEmail below

    <script>
     function ValidateEmail(inputText)
    {
  var mailformat = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/;
    if(inputText.value.match(mailformat))
    {
    alert("Valid email address!");
    document.form1.text1.focus();
    return true;
    }
    else
   {
    alert("You have entered an invalid email address!");
    document.form1.text1.focus();
    return false;
    }
    }
   </script>

Protect image download

1. Disable the Right Click on all Images

let allImages = document.querySelectorAll("img");
allImages.forEach((value)=>{
    value.oncontextmenu = (e)=>{
        e.preventDefault();
    }
})

2. Disable the Pointer Event Using CSS

img{
    pointer-events: none;
}

3. Put a transparent overlay over all the Images

<div class="imageContainer">
    <div class="overlayDiv"></div>
    <img src="Image.jpg" alt="Image">
</div>

And some CSS like this

.imageContainer{
    position: relative;
}
img{
    position: absolute;
    width: 100%;
    height: auto;
    top: 0px;
    left: 0px;
}
.overlayDiv{
    position: absolute;
    width: 100%;
    height: auto;
    top: 0px;
    left: 0px;
    background-color: transparent;
    z-index: 2;
}

4. Put your Image as a Background Image

div{
    background-image: url(Image.jpg);
    background-size: cover;
}

These methods will only work on normal users because they most probably don't know about the inspector or how to check source code.
But a web developer can easily download these files, there is no such way you can disable the inspector completely.



At the end i would like to add few words.

Technically, Now think about this you are sending a Image from your server to another computer over HTTP, and you are at the same time trying to prevent it, it doesn't make any sense.....

you should always assume that anything that enters the machine of the user can be retrieved back now or later, no matter how hard you try, to hide it with encryption or maybe like youtube, sending the thing in chunks, and collecting them in browser.

getting the image ultimately is hard for a common user but not for people with a lot of technical background, maybe they are intercepting the entire network on Operating System Level, how you gonna stop them there.

Convert Mat to Array/Vector in OpenCV

You can use iterators:

Mat matrix = ...;

std::vector<float> vec(matrix.begin<float>(), matrix.end<float>());

How to upgrade all Python packages with pip

One line in PowerShell 5.1 with administrator rights, Python 3.6.5, and pip version 10.0.1:

pip list -o --format json | ConvertFrom-Json | foreach {pip install $_.name -U --no-warn-script-location}

It works smoothly if there are no broken packages or special wheels in the list...

C# 4.0 optional out/ref arguments

void foo(ref int? n)
{
    return null;
}

favicon.png vs favicon.ico - why should I use PNG instead of ICO?

An ico can be a png.

More precisely, you can store one or more png inside this minimal container format, instead of the usual bitmap+alpha that everyone strongly associates with ico.

Support is old, appearing in Windows Vista (2007) and is well supported by browsers, though not necessarily by icon editing software.

Any valid png (whole including header) can be prepended by a 6 byte ico header and 16 byte image directory.
GIMP has native support. Simply export as ico and tick "Compressed (PNG)".

Store query result in a variable using in PL/pgSQL

Create Learning Table:

CREATE TABLE "public"."learning" (
    "api_id" int4 DEFAULT nextval('share_api_api_id_seq'::regclass) NOT NULL,
    "title" varchar(255) COLLATE "default"
);

Insert Data Learning Table:

INSERT INTO "public"."learning" VALUES ('1', 'Google AI-01');
INSERT INTO "public"."learning" VALUES ('2', 'Google AI-02');
INSERT INTO "public"."learning" VALUES ('3', 'Google AI-01');

Step: 01

CREATE OR REPLACE FUNCTION get_all (pattern VARCHAR) RETURNS TABLE (
        learn_id INT,
        learn_title VARCHAR
) AS $$
BEGIN
    RETURN QUERY SELECT
        api_id,
        title
    FROM
        learning
    WHERE
        title = pattern ;
END ; $$ LANGUAGE 'plpgsql';

Step: 02

SELECT * FROM get_all('Google AI-01');

Step: 03

DROP FUNCTION get_all();

Demo: enter image description here

UITextField border color

To simplify this actions from accepted answer, you can also create Category for UIView (since this works for all subclasses of UIView, not only for textfields:

UIView+Additions.h:

#import <Foundation/Foundation.h>

@interface UIView (Additions)
- (void)setBorderForColor:(UIColor *)color 
                    width:(float)width 
                   radius:(float)radius;
@end

UIView+Additions.m:

#import "UIView+Additions.h"

@implementation UIView (Additions)

- (void)setBorderForColor:(UIColor *)color 
                    width:(float)width
                   radius:(float)radius
{
    self.layer.cornerRadius = radius;
    self.layer.masksToBounds = YES;
    self.layer.borderColor = [color CGColor];
    self.layer.borderWidth = width;
}

@end

Usage:

#import "UIView+Additions.h"
//...
[textField setBorderForColor:[UIColor redColor]
                       width:1.0f
                      radius:8.0f];

Converting int to bytes in Python 3

If the question is how to convert an integer itself (not its string equivalent) into bytes, I think the robust answer is:

>>> i = 5
>>> i.to_bytes(2, 'big')
b'\x00\x05'
>>> int.from_bytes(i.to_bytes(2, 'big'), byteorder='big')
5

More information on these methods here:

  1. https://docs.python.org/3.8/library/stdtypes.html#int.to_bytes
  2. https://docs.python.org/3.8/library/stdtypes.html#int.from_bytes

VBA, if a string contains a certain letter

Not sure if this is what you're after, but it will loop through the range that you gave it and if it finds an "A" it will remove it from the cell. I'm not sure what oldStr is used for...

Private Sub foo()
Dim myString As String
RowCount = WorksheetFunction.CountA(Range("A:A"))

For i = 2 To RowCount
    myString = Trim(Cells(i, 1).Value)
    If InStr(myString, "A") > 0 Then
        Cells(i, 1).Value = Left(myString, InStr(myString, "A"))
    End If
Next
End Sub

Rebase array keys after unsetting elements

Got another interesting method:

$array = array('a', 'b', 'c', 'd'); 
unset($array[2]); 

$array = array_merge($array); 

Now the $array keys are reset.

Python: fastest way to create a list of n lists

So I did some speed comparisons to get the fastest way. List comprehensions are indeed very fast. The only way to get close is to avoid bytecode getting exectuded during construction of the list. My first attempt was the following method, which would appear to be faster in principle:

l = [[]]
for _ in range(n): l.extend(map(list,l))

(produces a list of length 2**n, of course) This construction is twice as slow as the list comprehension, according to timeit, for both short and long (a million) lists.

My second attempt was to use starmap to call the list constructor for me, There is one construction, which appears to run the list constructor at top speed, but still is slower, but only by a tiny amount:

from itertools import starmap
l = list(starmap(list,[()]*(1<<n)))

Interesting enough the execution time suggests that it is the final list call that is makes the starmap solution slow, since its execution time is almost exactly equal to the speed of:

l = list([] for _ in range(1<<n))

My third attempt came when I realized that list(()) also produces a list, so I tried the apperently simple:

l = list(map(list, [()]*(1<<n)))

but this was slower than the starmap call.

Conclusion: for the speed maniacs: Do use the list comprehension. Only call functions, if you have to. Use builtins.

Regular Expression - 2 letters and 2 numbers in C#

This should get you for starting with two letters and ending with two numbers.

[A-Za-z]{2}(.*)[0-9]{2}

If you know it will always be just two and two you can

[A-Za-z]{2}[0-9]{2}

How to get number of rows inserted by a transaction

I found the answer to may previous post. Here it is.

CREATE TABLE #TempTable (id int) 

INSERT INTO @TestTable (col1, col2) OUTPUT INSERTED.id INTO #TempTable select 1,2 

INSERT INTO @TestTable (col1, col2) OUTPUT INSERTED.id INTO #TempTable select 3,4 

SELECT * FROM #TempTable --this select will chage @@ROWCOUNT value

How to pass object with NSNotificationCenter

You'll have to use the "userInfo" variant and pass a NSDictionary object that contains the messageTotal integer:

NSDictionary* userInfo = @{@"total": @(messageTotal)};

NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
[nc postNotificationName:@"eRXReceived" object:self userInfo:userInfo];

On the receiving end you can access the userInfo dictionary as follows:

-(void) receiveTestNotification:(NSNotification*)notification
{
    if ([notification.name isEqualToString:@"TestNotification"])
    {
        NSDictionary* userInfo = notification.userInfo;
        NSNumber* total = (NSNumber*)userInfo[@"total"];
        NSLog (@"Successfully received test notification! %i", total.intValue);
    }
}

Sending mass email using PHP

Why don't you rather use phplist? It's also built on top of PHP Mailer and a lot of industry leaders are using it. I've used it myself a couple of times to send out bulk mails to my clients. The nice thing about phplist is that you can throttle your messages on a domain level plus a time limit level.

What we've also done with a couple of internal capture systems we've got was to push our user base to the mailling list and then have a cron entry triggering a given mail each day. The possibilities are endless, that's the awesome thing about open source!

Choice between vector::resize() and vector::reserve()

reserve when you do not want the objects to be initialized when reserved. also, you may prefer to logically differentiate and track its count versus its use count when you resize. so there is a behavioral difference in the interface - the vector will represent the same number of elements when reserved, and will be 100 elements larger when resized in your scenario.

Is there any better choice in this kind of scenario?

it depends entirely on your aims when fighting the default behavior. some people will favor customized allocators -- but we really need a better idea of what it is you are attempting to solve in your program to advise you well.

fwiw, many vector implementations will simply double the allocated element count when they must grow - are you trying to minimize peak allocation sizes or are you trying to reserve enough space for some lock free program or something else?

Typescript sleep

This works: (thanks to the comments)

setTimeout(() => 
{
    this.router.navigate(['/']);
},
5000);

Save classifier to disk in scikit-learn

You can also use joblib.dump and joblib.load which is much more efficient at handling numerical arrays than the default python pickler.

Joblib is included in scikit-learn:

>>> import joblib
>>> from sklearn.datasets import load_digits
>>> from sklearn.linear_model import SGDClassifier

>>> digits = load_digits()
>>> clf = SGDClassifier().fit(digits.data, digits.target)
>>> clf.score(digits.data, digits.target)  # evaluate training error
0.9526989426822482

>>> filename = '/tmp/digits_classifier.joblib.pkl'
>>> _ = joblib.dump(clf, filename, compress=9)

>>> clf2 = joblib.load(filename)
>>> clf2
SGDClassifier(alpha=0.0001, class_weight=None, epsilon=0.1, eta0=0.0,
       fit_intercept=True, learning_rate='optimal', loss='hinge', n_iter=5,
       n_jobs=1, penalty='l2', power_t=0.5, rho=0.85, seed=0,
       shuffle=False, verbose=0, warm_start=False)
>>> clf2.score(digits.data, digits.target)
0.9526989426822482

Edit: in Python 3.8+ it's now possible to use pickle for efficient pickling of object with large numerical arrays as attributes if you use pickle protocol 5 (which is not the default).

Sort Go map values by keys

According to the Go spec, the order of iteration over a map is undefined, and may vary between runs of the program. In practice, not only is it undefined, it's actually intentionally randomized. This is because it used to be predictable, and the Go language developers didn't want people relying on unspecified behavior, so they intentionally randomized it so that relying on this behavior was impossible.

What you'll have to do, then, is pull the keys into a slice, sort them, and then range over the slice like this:

var m map[keyType]valueType
keys := sliceOfKeys(m) // you'll have to implement this
for _, k := range keys {
    v := m[k]
    // k is the key and v is the value; do your computation here
}

HTML / CSS Popup div on text click

DEMO

In the content area you can provide whatever you want to display in it.

_x000D_
_x000D_
.black_overlay {_x000D_
  display: none;_x000D_
  position: absolute;_x000D_
  top: 0%;_x000D_
  left: 0%;_x000D_
  width: 100%;_x000D_
  height: 100%;_x000D_
  background-color: black;_x000D_
  z-index: 1001;_x000D_
  -moz-opacity: 0.8;_x000D_
  opacity: .80;_x000D_
  filter: alpha(opacity=80);_x000D_
}_x000D_
.white_content {_x000D_
  display: none;_x000D_
  position: absolute;_x000D_
  top: 25%;_x000D_
  left: 25%;_x000D_
  width: 50%;_x000D_
  height: 50%;_x000D_
  padding: 16px;_x000D_
  border: 16px solid orange;_x000D_
  background-color: white;_x000D_
  z-index: 1002;_x000D_
  overflow: auto;_x000D_
}
_x000D_
<html>_x000D_
_x000D_
<head>_x000D_
  <title>LIGHTBOX EXAMPLE</title>_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
  <p>This is the main content. To display a lightbox click <a href="javascript:void(0)" onclick="document.getElementById('light').style.display='block';document.getElementById('fade').style.display='block'">here</a>_x000D_
  </p>_x000D_
  <div id="light" class="white_content">This is the lightbox content. <a href="javascript:void(0)" onclick="document.getElementById('light').style.display='none';document.getElementById('fade').style.display='none'">Close</a>_x000D_
  </div>_x000D_
  <div id="fade" class="black_overlay"></div>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

How to use paths in tsconfig.json?

This can be set up on your tsconfig.json file, as it is a TS feature.

You can do like this:

"compilerOptions": {
        "baseUrl": "src", // This must be specified if "paths" is.
         ...
        "paths": {
            "@app/*": ["app/*"],
            "@config/*": ["app/_config/*"],
            "@environment/*": ["environments/*"],
            "@shared/*": ["app/_shared/*"],
            "@helpers/*": ["helpers/*"]
        },
        ...

Have in mind that the path where you want to refer to, it takes your baseUrl as the base of the route you are pointing to and it's mandatory as described on the doc.

The character '@' is not mandatory.

After you set it up on that way, you can easily use it like this:

import { Yo } from '@config/index';

the only thing you might notice is that the intellisense does not work in the current latest version, so I would suggest to follow an index convention for importing/exporting files.

https://www.typescriptlang.org/docs/handbook/module-resolution.html#path-mapping

Equivalent of Clean & build in Android Studio?

Also you can edit your Run/Debug configuration and add clean task.

Click on the Edit configuration

Click on the Edit configuration

In the left list of available configurations choose your current configuration and then on the right side of the dialog window in the section Before launch press on plus sign and choose Run Gradle task

choose <code>Run Gradle task</code>

In the new window choose your gradle project and in the field Tasks type clean.

type <code>clean</code>

Then move your gradle clean on top of Gradle-Aware make

Filter df when values matches part of a string in pyspark

pyspark.sql.Column.contains() is only available in pyspark version 2.2 and above.

df.where(df.location.contains('google.com'))

How to do a redirect to another route with react-router?

For the simple answer, you can use Link component from react-router, instead of button. There is ways to change the route in JS, but seems you don't need that here.

<span className="input-group-btn">
  <Link to="/login" />Click to login</Link>
</span>

To do it programmatically in 1.0.x, you do like this, inside your clickHandler function:

this.history.pushState(null, 'login');

Taken from upgrade doc here

You should have this.history placed on your route handler component by react-router. If it child component beneath that mentioned in routes definition, you may need pass that down further

HQL ERROR: Path expected for join

You need to name the entity that holds the association to User. For example,

... INNER JOIN ug.user u ...

That's the "path" the error message is complaining about -- path from UserGroup to User entity.

Hibernate relies on declarative JOINs, for which the join condition is declared in the mapping metadata. This is why it is impossible to construct the native SQL query without having the path.

Trying to get the average of a count resultset

You just can put your query as a subquery:

SELECT avg(count)
  FROM 
    (
    SELECT COUNT (*) AS Count
      FROM Table T
     WHERE T.Update_time =
               (SELECT MAX (B.Update_time )
                  FROM Table B
                 WHERE (B.Id = T.Id))
    GROUP BY T.Grouping
    ) as counts

Edit: I think this should be the same:

SELECT count(*) / count(distinct T.Grouping)
  FROM Table T
 WHERE T.Update_time =
           (SELECT MAX (B.Update_time)
              FROM Table B
             WHERE (B.Id = T.Id))

Extending from two classes

Extending from multiple classes is not allowed in java.. to prevent Deadly Diamond of death !

Android: keep Service running when app is killed

If your Service is started by your app then actually your service is running on main process. so when app is killed service will also be stopped. So what you can do is, send broadcast from onTaskRemoved method of your service as follows:

 Intent intent = new Intent("com.android.ServiceStopped");
 sendBroadcast(intent);

and have an broadcast receiver which will again start a service. I have tried it. service restarts from all type of kills.

This Handler class should be static or leaks might occur: IncomingHandler

If IncomingHandler class is not static, it will have a reference to your Service object.

Handler objects for the same thread all share a common Looper object, which they post messages to and read from.

As messages contain target Handler, as long as there are messages with target handler in the message queue, the handler cannot be garbage collected. If handler is not static, your Service or Activity cannot be garbage collected, even after being destroyed.

This may lead to memory leaks, for some time at least - as long as the messages stay int the queue. This is not much of an issue unless you post long delayed messages.

You can make IncomingHandler static and have a WeakReference to your service:

static class IncomingHandler extends Handler {
    private final WeakReference<UDPListenerService> mService; 

    IncomingHandler(UDPListenerService service) {
        mService = new WeakReference<UDPListenerService>(service);
    }
    @Override
    public void handleMessage(Message msg)
    {
         UDPListenerService service = mService.get();
         if (service != null) {
              service.handleMessage(msg);
         }
    }
}

See this post by Romain Guy for further reference

How can I resize an image using Java?

I have developed a solution with the freely available classes ( AnimatedGifEncoder, GifDecoder, and LWZEncoder) available for handling GIF Animation.
You can download the jgifcode jar and run the GifImageUtil class. Link: http://www.jgifcode.com

Paging with LINQ for objects

   ( for o in objects
    where ...
    select new
   {
     A=o.a,
     B=o.b
   })
.Skip((page-1)*pageSize)
.Take(pageSize)

How to use opencv in using Gradle?

OpenCV, Android Studio 1.4.1, gradle-experimental plugin 0.2.1

None of the other answers helped me. Here's what worked for me. I'm using the tutorial-1 sample from opencv but I will be doing using the NDK in my project so I'm using the gradle-experimental plugin which has a different structure than the gradle plugin.

Android studio should be installed, the Android NDK should be installed via the Android SDK Manager, and the OpenCV Android SDK should be downloaded and unzipped.

This is in chunks of bash script to keep it compact but complete. It's also all on the command line because on of the big problems I had was that in-IDE instructions were obsolete as the IDE evolved.

First set the location of the root directory of the OpenCV SDK.

export OPENCV_SDK=/home/user/wip/OpenCV-2.4.11-android-sdk
cd $OPENCV_SDK

Create your gradle build files...

First the OpenCV library

cat > $OPENCV_SDK/sdk/java/build.gradle <<'==='


apply plugin: 'com.android.model.library'
model {
    android {
        compileSdkVersion = 23
        buildToolsVersion = "23.0.2"

        defaultConfig.with {
            minSdkVersion.apiLevel = 8
            targetSdkVersion.apiLevel = 23
        }
    }

    android.buildTypes {
        release {
            minifyEnabled = false
        }
        debug{
            minifyEnabled = false
        }
    }
   android.sources {
       main.manifest.source.srcDirs +=  "."
       main.res.source.srcDirs +=  "res"
       main.aidl.source.srcDirs +=  "src"
       main.java.source.srcDirs +=  "src"
   }

}


===

Then tell the tutorial sample what to label the library as and where to find it.

cat > $OPENCV_SDK/samples/tutorial-1-camerapreview/settings.gradle <<'==='


include ':openCVLibrary2411'
project(':openCVLibrary2411').projectDir = new File('../../sdk/java')


===

Create the build file for the tutorial.

cat > $OPENCV_SDK/samples/tutorial-1-camerapreview/build.gradle <<'==='


buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle-experimental:0.2.1'
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

apply plugin: 'com.android.model.application'

model {
    android {
        compileSdkVersion = 23
        buildToolsVersion = "23.0.2"

        defaultConfig.with {
            applicationId = "org.opencv.samples.tutorial1"
            minSdkVersion.apiLevel = 8
            targetSdkVersion.apiLevel = 23
        }
    }

    android.sources {
       main.manifest.source.srcDirs +=  "."
       main.res.source.srcDirs +=  "res"
       main.aidl.source.srcDirs +=  "src"
       main.java.source.srcDirs +=  "src"
    } 

    android.buildTypes {
        release {
            minifyEnabled = false
            proguardFiles += file('proguard-rules.pro')
        }
        debug {
             minifyEnabled = false
        }
    }
}

dependencies {
    compile project(':openCVLibrary2411')
}


===

Your build tools version needs to be set correctly. Here's an easy way to see what you have installed. (You can install other versions via the Android SDK Manager). Change buildToolsVersion if you don't have 23.0.2.

echo "Your buildToolsVersion is one of: "
ls $ANDROID_HOME/build-tools

Change the environment variable on the first line to your version number

REP=23.0.2 #CHANGE ME
sed -i.bak s/23\.0\.2/${REP}/g $OPENCV_SDK/sdk/java/build.gradle
sed -i.bak s/23\.0\.2/${REP}/g $OPENCV_SDK/samples/tutorial-1-camerapreview/build.gradle

Finally, set up the correct gradle wrapper. Gradle needs a clean directory to do this.

pushd $(mktemp -d)

gradle wrapper --gradle-version 2.5

mv -f gradle* $OPENCV_SDK/samples/tutorial-1-camerapreview
popd

You should now be all set. You can now browse to this directory with Android Studio and open up the project.

Build the tutoral on the command line with the following command:

./gradlew assembleDebug

It should build your apk, putting it in ./build/outputs/apk

How to calculate an age based on a birthday?

I do it like this:

(Shortened the code a bit)

public struct Age
{
    public readonly int Years;
    public readonly int Months;
    public readonly int Days;

}

public Age( int y, int m, int d ) : this()
{
    Years = y;
    Months = m;
    Days = d;
}

public static Age CalculateAge ( DateTime birthDate, DateTime anotherDate )
{
    if( startDate.Date > endDate.Date )
        {
            throw new ArgumentException ("startDate cannot be higher then endDate", "startDate");
        }

        int years = endDate.Year - startDate.Year;
        int months = 0;
        int days = 0;

        // Check if the last year, was a full year.
        if( endDate < startDate.AddYears (years) && years != 0 )
        {
            years--;
        }

        // Calculate the number of months.
        startDate = startDate.AddYears (years);

        if( startDate.Year == endDate.Year )
        {
            months = endDate.Month - startDate.Month;
        }
        else
        {
            months = ( 12 - startDate.Month ) + endDate.Month;
        }

        // Check if last month was a complete month.
        if( endDate < startDate.AddMonths (months) && months != 0 )
        {
            months--;
        }

        // Calculate the number of days.
        startDate = startDate.AddMonths (months);

        days = ( endDate - startDate ).Days;

        return new Age (years, months, days);
}

// Implement Equals, GetHashCode, etc... as well
// Overload equality and other operators, etc...

}

Javascript Image Resize

Here is my cover fill solution (similar to background-size: cover, but it supports old IE browser)

<div class="imgContainer" style="height:100px; width:500px; overflow:hidden; background-color: black">
    <img src="http://dev.isaacsonwebdevelopment.com/sites/development/files/views-slideshow-settings-jquery-cycle-custom-options-message.png" id="imgCat">
</div>
<script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.11.3.min.js"></script>
<script>
    $(window).load(function() {
        var heightRate =$("#imgCat").height() / $("#imgCat").parent(".imgContainer").height();
        var widthRate = $("#imgCat").width() / $("#imgCat").parent(".imgContainer").width();

        if (window.console) {
            console.log($("#imgCat").height());
            console.log(heightRate);
            console.log(widthRate);
            console.log(heightRate > widthRate);
        }
        if (heightRate <= widthRate) {
            $("#imgCat").height($("#imgCat").parent(".imgContainer").height());
        } else {
            $("#imgCat").width($("#imgCat").parent(".imgContainer").width());
        }
    });
</script>

Recommended date format for REST GET API

Always use UTC:

For example I have a schedule component that takes in one parameter DATETIME. When I call this using a GET verb I use the following format where my incoming parameter name is scheduleDate.

Example:
https://localhost/api/getScheduleForDate?scheduleDate=2003-11-21T01:11:11Z

How to detect string which contains only spaces?

Similar to Rory's answer, with ECMA 5 you can now just call str.trim().length instead of using a regular expression. If the resulting value is 0 you know you have a string that contains only spaces.

if (!str.trim().length) {
  console.log('str is empty!');
}

You can read more about trim here.

How to validate an email address in PHP

Use below code:

// Variable to check
$email = "[email protected]";

// Remove all illegal characters from email
$email = filter_var($email, FILTER_SANITIZE_EMAIL);

// Validate e-mail
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
  echo("Email is a valid email address");
} else {
  echo("Oppps! Email is not a valid email address");
}

Reason to Pass a Pointer by Reference in C++?

You would want to pass a pointer by reference if you have a need to modify the pointer rather than the object that the pointer is pointing to.

This is similar to why double pointers are used; using a reference to a pointer is slightly safer than using pointers.

How does one set up the Visual Studio Code compiler/debugger to GCC?

Ctrl+P and Type "ext install cpptools" it will install everything you need to debug c and c++.

Debugging in VS code is very complete, but if you just need to compile and run: https://code.visualstudio.com/docs/languages/cpp

Look in the debugging section and it will explain everything

What is difference between INNER join and OUTER join

Inner join matches tables on keys, but outer join matches keys just for one side. For example when you use left outer join the query brings the whole left side table and matches the right side to the left table primary key and where there is not matched places null.

ASP.Net MVC: How to display a byte array image from model

If the image isn't that big, and if there's a good chance you'll be re-using the image often, and if you don't have too many of them, and if the images are not secret (meaning it's no big deal if one user could potentially see another person's image)...

Lots of "if"s here, so there's a good chance this is a bad idea:

You can store the image bytes in Cache for a short time, and make an image tag pointed toward an action method, which in turn reads from the cache and spits out your image. This will allow the browser to cache the image appropriately.

// In your original controller action
HttpContext.Cache.Add("image-" + model.Id, model.ImageBytes, null,
    Cache.NoAbsoluteExpiration, TimeSpan.FromMinutes(1),
    CacheItemPriority.Normal, null);

// In your view:
<img src="@Url.Action("GetImage", "MyControllerName", new{fooId = Model.Id})">

// In your controller:
[OutputCache(VaryByParam = "fooId", Duration = 60)]
public ActionResult GetImage(int fooId) {
    // Make sure you check for null as appropriate, re-pull from DB, etc.
    return File((byte[])HttpContext.Cache["image-" + fooId], "image/gif");
}

This has the added benefit (or is it a crutch?) of working in older browsers, where the inline images don't work in IE7 (or IE8 if larger than 32kB).

What is the difference between require() and library()?

In addition to the good advice already given, I would add this:

It is probably best to avoid using require() unless you actually will be using the value it returns e.g in some error checking loop such as given by thierry.

In most other cases it is better to use library(), because this will give an error message at package loading time if the package is not available. require() will just fail without an error if the package is not there. This is the best time to find out if the package needs to be installed (or perhaps doesn't even exist because it it spelled wrong). Getting error feedback early and at the relevant time will avoid possible headaches with tracking down why later code fails when it attempts to use library routines

How to vertically align text inside a flexbox?

Instead of using align-self: center use align-items: center.

There's no need to change flex-direction or use text-align.

Here's your code, with one adjustment, to make it all work:

ul {
  height: 100%;
}

li {
  display: flex;
  justify-content: center;
  /* align-self: center;    <---- REMOVE */
  align-items: center;   /* <---- NEW    */
  background: silver;
  width: 100%;
  height: 20%; 
}

The align-self property applies to flex items. Except your li is not a flex item because its parent – the ul – does not have display: flex or display: inline-flex applied.

Therefore, the ul is not a flex container, the li is not a flex item, and align-self has no effect.

The align-items property is similar to align-self, except it applies to flex containers.

Since the li is a flex container, align-items can be used to vertically center the child elements.

_x000D_
_x000D_
* {_x000D_
  padding: 0;_x000D_
  margin: 0;_x000D_
}_x000D_
html, body {_x000D_
  height: 100%;_x000D_
}_x000D_
ul {_x000D_
  height: 100%;_x000D_
}_x000D_
li {_x000D_
  display: flex;_x000D_
  justify-content: center;_x000D_
  /* align-self: center; */_x000D_
  align-items: center;_x000D_
  background: silver;_x000D_
  width: 100%;_x000D_
  height: 20%;_x000D_
}
_x000D_
<ul>_x000D_
  <li>This is the text</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

codepen demo


Technically, here's how align-items and align-self work...

The align-items property (on the container) sets the default value of align-self (on the items). Therefore, align-items: center means all flex items will be set to align-self: center.

But you can override this default by adjusting the align-self on individual items.

For example, you may want equal height columns, so the container is set to align-items: stretch. However, one item must be pinned to the top, so it is set to align-self: flex-start.

example


How is the text a flex item?

Some people may be wondering how a run of text...

<li>This is the text</li>

is a child element of the li.

The reason is that text that is not explicitly wrapped by an inline-level element is algorithmically wrapped by an inline box. This makes it an anonymous inline element and child of the parent.

From the CSS spec:

9.2.2.1 Anonymous inline boxes

Any text that is directly contained inside a block container element must be treated as an anonymous inline element.

The flexbox specification provides for similar behavior.

4. Flex Items

Each in-flow child of a flex container becomes a flex item, and each contiguous run of text that is directly contained inside a flex container is wrapped in an anonymous flex item.

Hence, the text in the li is a flex item.

Why GDB jumps unpredictably between lines and prints variables as "<value optimized out>"?

When debugging optimized programs (which may be necessary if the bug doesn't show up in debug builds), you often have to understand assembly compiler generated.

In your particular case, return value of cpnd_find_exact_ckptinfo will be stored in the register which is used on your platform for return values. On ix86, that would be %eax. On x86_64: %rax, etc. You may need to google for '[your processor] procedure calling convention' if it's none of the above.

You can examine that register in GDB and you can set it. E.g. on ix86:

(gdb) p $eax
(gdb) set $eax = 0 

How to fix C++ error: expected unqualified-id

Get rid of the semicolon after WordGame.

You really should have discovered this problem when the class was a lot smaller. When you're writing code, you should be compiling about every time you add half a dozen lines.

java.net.URL read stream to byte[]

It's important to specify timeouts, especially when the server takes to respond. With pure Java, without using any dependency:

public static byte[] copyURLToByteArray(final String urlStr,
        final int connectionTimeout, final int readTimeout) 
                throws IOException {
    final URL url = new URL(urlStr);
    final URLConnection connection = url.openConnection();
    connection.setConnectTimeout(connectionTimeout);
    connection.setReadTimeout(readTimeout);
    try (InputStream input = connection.getInputStream();
            ByteArrayOutputStream output = new ByteArrayOutputStream()) {
        final byte[] buffer = new byte[8192];
        for (int count; (count = input.read(buffer)) > 0;) {
            output.write(buffer, 0, count);
        }
        return output.toByteArray();
    }
}

Using dependencies, e.g., HC Fluent:

public byte[] copyURLToByteArray(final String urlStr,
        final int connectionTimeout, final int readTimeout)
                throws IOException {
    return Request.Get(urlStr)
            .connectTimeout(connectionTimeout)
            .socketTimeout(readTimeout)
            .execute()
            .returnContent()
            .asBytes();
}

Eclipse: Error ".. overlaps the location of another project.." when trying to create new project

This too took me sometime to figure out.

Solution:

To create a new Maven Project under the existing workspace, just have the "Use default Workspace location" ticked (Ignore what is in the grayed out location text input).

The name of the project will be determined by you Artifact Id in step 2 of the creation wizard.

Reasoning:

It was so confusing because in my case, because when I selected to create a new Maven Project: the default workspace loaction is ticked and directly proceeding it is the grayed out "Location" text input had the workspace location + the existing project I was looking at before choose to create a new Maven Project. (ie: Location = '[workspace path]/last looked at project')

So I unticked the default workspace location box and entered in '[workspace path]/new project', which didn't work because eclipse expects the [workspace path] to be different compared to the default path. (Otherwise we would of selected the default workspace check box).

Convert an image (selected by path) to base64 string

That way it's simpler, where you pass the image and then pass the format.

private static string ImageToBase64(Image image)
{
    var imageStream = new MemoryStream();
    try
    {           
        image.Save(imageStream, System.Drawing.Imaging.ImageFormat.Bmp);
        imageStream.Position = 0;
        var imageBytes = imageStream.ToArray();
        var ImageBase64 = Convert.ToBase64String(imageBytes);
        return ImageBase64;
    }
    catch (Exception ex)
    {
        return "Error converting image to base64!";
    }
    finally
    {
      imageStream.Dispose;
    }
}

Create a remote branch on GitHub

It looks like github has a simple UI for creating branches. I opened the branch drop-down and it prompts me to "Find or create a branch ...". Type the name of your new branch, then click the "create" button that appears.

To retrieve your new branch from github, use the standard git fetch command.

create branch github ui

I'm not sure this will help your underlying problem, though, since the underlying data being pushed to the server (the commit objects) is the same no matter what branch it's being pushed to.

Getting the folder name from a path

Simple & clean. Only uses System.IO.FileSystem - works like a charm:

string path = "C:/folder1/folder2/file.txt";
string folder = new DirectoryInfo(path).Name;

How to get a value of an element by name instead of ID

This works fine .. here btnAddCat is button id

$('#btnAddCat').click(function(){
        var eventCategory=$("input[name=txtCategory]").val();
        alert(eventCategory);
    });

What are public, private and protected in object oriented programming?

as above, but qualitatively:

private - least access, best encapsulation
protected - some access, moderate encapsulation
public - full access, no encapsulation

the less access you provide the fewer implementation details leak out of your objects. less of this sort of leakage means more flexibility (aka "looser coupling") in terms of changing how an object is implemented without breaking clients of the object. this is a truly fundamental thing to understand.

maven "cannot find symbol" message unhelpful

In my case, I was using a dependency scoped as <scope>test</scope>. This made the class available at development time but, by at compile time, I got this message.

Turn the class scope for <scope>provided</scope> solved the problem.

How to insert text into the textarea at the current cursor position?


_x000D_
_x000D_
function insertAtCaret(text) {_x000D_
  const textarea = document.querySelector('textarea')_x000D_
  textarea.setRangeText(_x000D_
    text,_x000D_
    textarea.selectionStart,_x000D_
    textarea.selectionEnd,_x000D_
    'end'_x000D_
  )_x000D_
}_x000D_
_x000D_
setInterval(() => insertAtCaret('Hello'), 3000)
_x000D_
<textarea cols="60">Stack Overflow Stack Exchange Starbucks Coffee</textarea>
_x000D_
_x000D_
_x000D_

INSERT INTO...SELECT for all MySQL columns

Addition to Mark Byers answer :

Sometimes you also want to insert Hardcoded details else there may be Unique constraint fail etc. So use following in such situation where you override some values of the columns.

INSERT INTO matrimony_domain_details (domain, type, logo_path)
SELECT 'www.example.com', type, logo_path
FROM matrimony_domain_details
WHERE id = 367

Here domain value is added by me me in Hardcoded way to get rid from Unique constraint.

How to display default text "--Select Team --" in combo box on pageload in WPF?

IceForge's answer was pretty close, and is AFAIK the easiest solution to this problem. But it missed something, as it wasn't working (at least for me, it never actually displays the text).

In the end, you can't just set the "Visibility" property of the TextBlock to "Hidden" in order for it to be hidden when the combo box's selected item isn't null; you have to SET it that way by default (since you can't check not null in triggers, by using a Setter in XAML at the same place as the Triggers.

Here's the actual solution based on his, the missing Setter being placed just before the Triggers:

<ComboBox x:Name="combo"/>
<TextBlock Text="--Select Team--" IsHitTestVisible="False">
    <TextBlock.Style>
        <Style TargetType="TextBlock">

            <Style.Setters>
                <Setter Property="Visibility" Value="Hidden"/>
            </Style.Setters>

            <Style.Triggers>
                <DataTrigger Binding="{Binding ElementName=combo,Path=SelectedItem}" Value="{x:Null}">
                    <Setter Property="Visibility" Value="Visible"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </TextBlock.Style>
</TextBlock>

Get a timestamp in C in microseconds?

use an unsigned long long (i.e. a 64 bit unit) to represent the system time:

typedef unsigned long long u64;

u64 u64useconds;
struct timeval tv;

gettimeofday(&tv,NULL);
u64useconds = (1000000*tv.tv_sec) + tv.tv_usec;

Register 32 bit COM DLL to 64 bit Windows 7

put the dll in system32 or syswow32 directory, and use appropriate regsvr32 to register it. wiered that even though it gave failed to register error, I rebooted my WIN 7 64 AND my vb app loaded the dll just fine!!

List all files in one directory PHP

You are looking for the command scandir.

$path    = '/tmp';
$files = scandir($path);

Following code will remove . and .. from the returned array from scandir:

$files = array_diff(scandir($path), array('.', '..'));

Configure hibernate to connect to database via JNDI Datasource

Inside applicationContext.xml file of a maven Hibernet web app project below settings worked for me.

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:jee="http://www.springframework.org/schema/jee"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
        http://www.springframework.org/schema/jee 
        http://www.springframework.org/schema/jee/spring-jee-3.0.xsd">



  <jee:jndi-lookup id="dataSource"
                 jndi-name="Give_DataSource_Path_From_Your_Server"
                 expected-type="javax.sql.DataSource" />


Hope It will help someone.Thanks!

List Git aliases

for windows:

git config --list | findstr "alias"

Difference between .on('click') vs .click()

Here you will get list of diffrent ways of applying the click event. You can select accordingly as suaitable or if your click is not working just try an alternative out of these.

$('.clickHere').click(function(){ 
     // this is flat click. this event will be attatched 
     //to element if element is available in 
     //dom at the time when JS loaded. 

  // do your stuff
});

$('.clickHere').on('click', function(){ 
    // same as first one

    // do your stuff
})

$(document).on('click', '.clickHere', function(){
          // this is diffrent type 
          //  of click. The click will be registered on document when JS 
          //  loaded and will delegate to the '.clickHere ' element. This is 
          //  called event delegation 
   // do your stuff
});

$('body').on('click', '.clickHere', function(){
   // This is same as 3rd 
   // point. Here we used body instead of document/

   // do your stuff
});

$('.clickHere').off().on('click', function(){ // 
    // deregister event listener if any and register the event again. This 
    // prevents the duplicate event resistration on same element. 
    // do your stuff
})

How to preserve request url with nginx proxy_pass

To perfectly forward without chopping the absoluteURI of the request and the Host in the header:

server {
    listen 35005;

    location / {
        rewrite            ^(.*)$   "://$http_host$uri$is_args$args";
        rewrite            ^(.*)$   "http$uri$is_args$args" break;
        proxy_set_header   Host     $host;

        proxy_pass         https://deploy.org.local:35005;
    }
}

Found here: https://opensysnotes.wordpress.com/2016/11/17/nginx-proxy_pass-with-absolute-url/

How to programmatically take a screenshot on Android?

You can try the following library: http://code.google.com/p/android-screenshot-library/ Android Screenshot Library (ASL) enables to programmatically capture screenshots from Android devices without requirement of having root access privileges. Instead, ASL utilizes a native service running in the background, started via the Android Debug Bridge (ADB) once per device boot.

No grammar constraints (DTD or XML schema) detected for the document

Have you tried to add a schema to xml catalog?

in eclipse to avoid the "no grammar constraints (dtd or xml schema) detected for the document." i use to add an xsd schema file to the xml catalog under

"Window \ preferences \ xml \ xml catalog \ User specified entries".

Click "Add" button on the right.


Example:

<?xml version="1.0" encoding="UTF-8"?>
<HolidayRequest xmlns="http://mycompany.com/hr/schemas">
    <Holiday>
        <StartDate>2006-07-03</StartDate>
        <EndDate>2006-07-07</EndDate>
    </Holiday>
    <Employee>
        <Number>42</Number>
        <FirstName>Arjen</FirstName>
        <LastName>Poutsma</LastName>
    </Employee>
</HolidayRequest>

From this xml i have generated and saved an xsd under: /home/my_user/xsd/my_xsd.xsd

As Location: /home/my_user/xsd/my_xsd.xsd

As key type: Namespace name

As key: http://mycompany.com/hr/schemas


Close and reopen the xml file and do some changes to violate the schema, you should be notified

How to get screen dimensions as pixels in Android

For accessing the height of the status bar for Android devices, we prefer a programmatic way to get it:

Sample code

int resId = getResources().getIdentifier("status_bar_height", "dimen", "android");
if (resId > 0) {
    result = getResources().getDimensionPixelSize(resId);
}

The variable result gives the height in the pixel.

For quick access

Enter image description here

For more information about height of Title bar, Navigation bar and Content View, kindly look on Android Device Screen Sizes.

Is this how you define a function in jQuery?

jQuery.fn.extend({
    zigzag: function () {
        var text = $(this).text();
        var zigzagText = '';
        var toggle = true; //lower/uppper toggle
            $.each(text, function(i, nome) {
                zigzagText += (toggle) ? nome.toUpperCase() : nome.toLowerCase();
                toggle = (toggle) ? false : true;
            });
    return zigzagText;
    }
});

android View not attached to window manager

I had this issue where on a screen orientation change, the activity finished before the AsyncTask with the progress dialog completed. I seemed to resolve this by setting the dialog to null onPause() and then checking this in the AsyncTask before dismissing.

@Override
public void onPause() {
    super.onPause();

    if ((mDialog != null) && mDialog.isShowing())
        mDialog.dismiss();
    mDialog = null;
}

... in my AsyncTask:

protected void onPreExecute() {
    mDialog = ProgressDialog.show(mContext, "", "Saving changes...",
            true);
}

protected void onPostExecute(Object result) {
   if ((mDialog != null) && mDialog.isShowing()) { 
        mDialog.dismiss();
   }
}

How do I get a file name from a full path with PHP?

The basename function should give you what you want:

Given a string containing a path to a file, this function will return the base name of the file.

For instance, quoting the manual's page:

<?php
    $path = "/home/httpd/html/index.php";
    $file = basename($path);         // $file is set to "index.php"
    $file = basename($path, ".php"); // $file is set to "index"
?>

Or, in your case:

$full = 'F:\Program Files\SSH Communications Security\SSH Secure Shell\Output.map';
var_dump(basename($full));

You'll get:

string(10) "Output.map"

Regular expression to match balanced parentheses

I have written a little JavaScript library called balanced to help with this task. You can accomplish this by doing

balanced.matches({
    source: source,
    open: '(',
    close: ')'
});

You can even do replacements:

balanced.replacements({
    source: source,
    open: '(',
    close: ')',
    replace: function (source, head, tail) {
        return head + source + tail;
    }
});

Here's a more complex and interactive example JSFiddle.

Getting the client's time zone (and offset) in JavaScript

On the new Date() you can get the offset, to get the timezone name you may do:

new Date().toString().replace(/(.*\((.*)\).*)/, '$2');

you get the value between () in the end of the date, that is the name of the timezone.

How to Test Facebook Connect Locally

I couldn't use the other solutions... What worked for me was installing LocalTunnel.net (https://github.com/danielrmz/localtunnel-net-client), and then using the resulting url on Facebook.

Can I concatenate multiple MySQL rows into one field?

I had a more complicated query, and found that I had to use GROUP_CONCAT in an outer query to get it to work:

Original Query:

SELECT DISTINCT userID 
FROM event GROUP BY userID 
HAVING count(distinct(cohort))=2);

Imploded:

SELECT GROUP_CONCAT(sub.userID SEPARATOR ', ') 
FROM (SELECT DISTINCT userID FROM event 
GROUP BY userID HAVING count(distinct(cohort))=2) as sub;

Hope this might help someone.

Convenient C++ struct initialisation

Yet another way in C++ is

struct Point
{
private:

 int x;
 int y;

public:
    Point& setX(int xIn) { x = Xin; return *this;}
    Point& setY(int yIn) { y = Yin; return *this;}

}

Point pt;
pt.setX(20).setY(20);

How to sleep for five seconds in a batch file/cmd

The following hack let's you sleep for 5 seconds

ping -n 6 127.0.0.1 > nul

Since ping waits a second between the pings, you have to specify one more than you need.

How to set border's thickness in percentages?

So this is an older question, but for those still looking for an answer, the CSS property Box-Sizing is priceless here:

-webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit  */
-moz-box-sizing: border-box;    /* Firefox, other Gecko         */
box-sizing: border-box; 

It means that you can set the width of the Div to a percentage, and any border you add to the div will be included within that percentage. So, for example, the following would add the 1px border to the inside of the width of the div:

div { box-sizing:border-box; width:50%; border-right:1px solid #000; }         

If you'd like more info: http://css-tricks.com/box-sizing/

Write / add data in JSON file using Node.js

For synchronous approach

const fs = require('fs')
fs.writeFileSync('file.json', JSON.stringify(jsonVariable));

How to compile for Windows on Linux with gcc/g++?

I've used mingw on Linux to make Windows executables in C, I suspect C++ would work as well.

I have a project, ELLCC, that packages clang and other things as a cross compiler tool chain. I use it to compile clang (C++), binutils, and GDB for Windows. Follow the download link at ellcc.org for pre-compiled binaries for several Linux hosts.

TypeError: You provided an invalid object where a stream was expected. You can provide an Observable, Promise, Array, or Iterable

In my case I mistakely imported Action into my combineEpics, rather than Epic...

Verify all the functions within combine Epics are epic funcitons

Adding a 'share by email' link to website

<a target="_blank" title="Share this page" href="http://www.sharethis.com/share?url=[INSERT URL]&title=[INSERT TITLE]&summary=[INSERT SUMMARY]&img=[INSERT IMAGE URL]&pageInfo=%7B%22hostname%22%3A%22[INSERT DOMAIN NAME]%22%2C%22publisher%22%3A%22[INSERT PUBLISHERID]%22%7D"><img width="86" height="25" alt="Share this page" src="http://w.sharethis.com/images/share-classic.gif"></a>

Instructions

First, insert these lines wherever you want within your newsletter code. Then:

  1. Change "INSERT URL" to whatever website holds the shared content.
  2. Change "INSERT TITLE" to the title of the article.
  3. Change "INSERT SUMMARY" to a short summary of the article.
  4. Change "INSERT IMAGE URL" to an image that will be shared with the rest of the content.
  5. Change "INSERT DOMAIN NAME" to your domain name.
  6. Change "INSERT PUBLISHERID" to your publisher ID (if you have an account, if not, remove "[INSERT PUBLISHERID]" or sign up!)

If you are using this on an email newsletter, make sure you add our sharing buttons to the destination page. This will ensure that you get complete sharing analytics for your page. Make sure you replace "INSERT PUBLISHERID" with your own.

Download multiple files as a zip-file using php

This is a working example of making ZIPs in PHP:

$zip = new ZipArchive();
$zip_name = time().".zip"; // Zip name
$zip->open($zip_name,  ZipArchive::CREATE);
foreach ($files as $file) {
  echo $path = "uploadpdf/".$file;
  if(file_exists($path)){
  $zip->addFromString(basename($path),  file_get_contents($path));  
  }
  else{
   echo"file does not exist";
  }
}
$zip->close();

Column "invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause"

Put in other words, this error is telling you that SQL Server does not know which B to select from the group.

Either you want to select one specific value (e.g. the MIN, SUM, or AVG) in which case you would use the appropriate aggregate function, or you want to select every value as a new row (i.e. including B in the GROUP BY field list).


Consider the following data:

ID  A   B
1   1  13
1   1  79
1   2  13
1   2  13
1   2  42

The query

SELECT A, COUNT(B) AS T1 
FROM T2 
GROUP BY A

would return:

A  T1
1  2
2  3

which is all well and good.

However consider the following (illegal) query, which would produce this error:

SELECT A, COUNT(B) AS T1, B 
FROM T2 
GROUP BY A

And its returned data set illustrating the problem:

A  T1  B
1  2   13? 79? Both 13 and 79 as separate rows? (13+79=92)? ...?
2  3   13? 42? ...?

However, the following two queries make this clear, and will not cause the error:

  1. Using an aggregate

    SELECT A, COUNT(B) AS T1, SUM(B) AS B
    FROM T2
    GROUP BY A
    

    would return:

    A  T1  B
    1  2   92
    2  3   68
    
  2. Adding the column to the GROUP BY list

    SELECT A, COUNT(B) AS T1, B
    FROM T2
    GROUP BY A, B
    

    would return:

    A  T1  B
    1  1   13
    1  1   79
    2  2   13
    2  1   42
    

MySQL error - #1932 - Table 'phpmyadmin.pma user config' doesn't exist in engine

make change in changes in /opt/lampp/phpmyadmin/config.inc.php    

<?php
    /* vim: set expandtab sw=4 ts=4 sts=4: */
    /**
     * phpMyAdmin sample configuration, you can use it as base for
     * manual configuration. For easier setup you can use setup/
     *
     * All directives are explained in documentation in the doc/ folder
     * or at <http://docs.phpmyadmin.net/>.
     *
     * @package PhpMyAdmin
     */

    /**
     * This is needed for cookie based authentication to encrypt password in
     * cookie
     */
    $cfg['blowfish_secret'] = 'xampp'; /* YOU SHOULD CHANGE THIS FOR A MORE SECURE COOKIE AUTH! */

    /**
     * Servers configuration
     */
    $i = 0;

    /**
     * First server
     */
    $i++;
    /* Authentication type */
    $cfg['Servers'][$i]['auth_type'] = 'config';
    $cfg['Servers'][$i]['user'] = 'root';
    $cfg['Servers'][$i]['password'] = '';
    /* Server parameters */
    //$cfg['Servers'][$i]['host'] = 'localhost';
    //$cfg['Servers'][$i]['connect_type'] = 'tcp';
    $cfg['Servers'][$i]['compress'] = false;
    $cfg['Servers'][$i]['AllowNoPassword'] = true;

    /**
     * phpMyAdmin configuration storage settings.
     */

    /* User used to manipulate with storage */
    // $cfg['Servers'][$i]['controlhost'] = '';
    // $cfg['Servers'][$i]['controlport'] = '';



    $cfg['Servers'][1]['pmadb'] = 'phpmyadmin';
    $cfg['Servers'][1]['controluser'] = 'pma';
    $cfg['Servers'][1]['controlpass'] = '';

    $cfg['Servers'][1]['bookmarktable'] = 'pma_bookmark';
    $cfg['Servers'][1]['relation'] = 'pma_relation';
    $cfg['Servers'][1]['userconfig'] = 'pma_userconfig';
    $cfg['Servers'][1]['table_info'] = 'pma_table_info';
    $cfg['Servers'][1]['column_info'] = 'pma_column_info';
    $cfg['Servers'][1]['history'] = 'pma_history';
    $cfg['Servers'][1]['recent'] = 'pma_recent';
    $cfg['Servers'][1]['table_uiprefs'] = 'pma_table_uiprefs';
    $cfg['Servers'][1]['tracking'] = 'pma_tracking';
    $cfg['Servers'][1]['table_coords'] = 'pma_table_coords';
    $cfg['Servers'][1]['pdf_pages'] = 'pma_pdf_pages';
    $cfg['Servers'][1]['designer_coords'] = 'pma_designer_coords';



    // $cfg['Servers'][$i]['favorite'] = 'pma__favorite';
    // $cfg['Servers'][$i]['users'] = 'pma__users';
    // $cfg['Servers'][$i]['usergroups'] = 'pma__usergroups';
    // $cfg['Servers'][$i]['navigationhiding'] = 'pma__navigationhiding';
    // $cfg['Servers'][$i]['savedsearches'] = 'pma__savedsearches';
    // $cfg['Servers'][$i]['central_columns'] = 'pma__central_columns';
    // $cfg['Servers'][$i]['designer_settings'] = 'pma__designer_settings';
    // $cfg['Servers'][$i]['export_templates'] = 'pma__export_templates';
    /* Contrib / Swekey authentication */
    // $cfg['Servers'][$i]['auth_swekey_config'] = '/etc/swekey-pma.conf';

    /**
     * End of servers configuration
     */

    /**
     * Directories for saving/loading files from server
     */
    $cfg['UploadDir'] = '';
    $cfg['SaveDir'] = '';

    /**
     * Whether to display icons or text or both icons and text in table row
     * action segment. Value can be either of 'icons', 'text' or 'both'.
     * default = 'both'
     */
    //$cfg['RowActionType'] = 'icons';

    /**
     * Defines whether a user should be displayed a "show all (records)"
     * button in browse mode or not.
     * default = false
     */
    //$cfg['ShowAll'] = true;

    /**
     * Number of rows displayed when browsing a result set. If the result
     * set contains more rows, "Previous" and "Next".
     * Possible values: 25, 50, 100, 250, 500
     * default = 25
     */
    //$cfg['MaxRows'] = 50;

    /**
     * Disallow editing of binary fields
     * valid values are:
     *   false    allow editing
     *   'blob'   allow editing except for BLOB fields
     *   'noblob' disallow editing except for BLOB fields
     *   'all'    disallow editing
     * default = 'blob'
     */
    //$cfg['ProtectBinary'] = false;

    /**
     * Default language to use, if not browser-defined or user-defined
     * (you find all languages in the locale folder)
     * uncomment the desired line:
     * default = 'en'
     */
    //$cfg['DefaultLang'] = 'en';
    //$cfg['DefaultLang'] = 'de';

    /**
     * How many columns should be used for table display of a database?
     * (a value larger than 1 results in some information being hidden)
     * default = 1
     */
    //$cfg['PropertiesNumColumns'] = 2;

    /**
     * Set to true if you want DB-based query history.If false, this utilizes
     * JS-routines to display query history (lost by window close)
     *
     * This requires configuration storage enabled, see above.
     * default = false
     */
    //$cfg['QueryHistoryDB'] = true;

    /**
     * When using DB-based query history, how many entries should be kept?
     * default = 25
     */
    //$cfg['QueryHistoryMax'] = 100;

    /**
     * Whether or not to query the user before sending the error report to
     * the phpMyAdmin team when a JavaScript error occurs
     *
     * Available options
     * ('ask' | 'always' | 'never')
     * default = 'ask'
     */
    //$cfg['SendErrorReports'] = 'always';

    /**
     * You can find more configuration options in the documentation
     * in the doc/ folder or at <http://docs.phpmyadmin.net/>.
     */

How to generate .env file for laravel?

.env files are hidden by Netbeans. To show them do this:

Tools > Options > Miscellaneous > Files

Under Files Ignored be the IDE is Ignored Files Pattern:

The default is

^(CVS|SCCS|vssver.?\.scc|#.*#|%.*%|_svn)$|~$|^\.(?!(htaccess|git.+|hgignore)$).*$

Add env to the excluded-not-excluded bit

^(CVS|SCCS|vssver.?\.scc|#.*#|%.*%|_svn)$|~$|^\.(?!(env|htaccess|git.+|hgignore)$).*$

Files named .env now show.

How can I implement a tree in Python?

class Tree(dict):
    """A tree implementation using python's autovivification feature."""
    def __missing__(self, key):
        value = self[key] = type(self)()
        return value

    #cast a (nested) dict to a (nested) Tree class
    def __init__(self, data={}):
        for k, data in data.items():
            if isinstance(data, dict):
                self[k] = type(self)(data)
            else:
                self[k] = data

works as a dictionary, but provides as many nested dicts you want. Try the following:

your_tree = Tree()

your_tree['a']['1']['x']  = '@'
your_tree['a']['1']['y']  = '#'
your_tree['a']['2']['x']  = '$'
your_tree['a']['3']       = '%'
your_tree['b']            = '*'

will deliver a nested dict ... which works as a tree indeed.

{'a': {'1': {'x': '@', 'y': '#'}, '2': {'x': '$'}, '3': '%'}, 'b': '*'}

... If you have already a dict, it will cast each level to a tree:

d = {'foo': {'amy': {'what': 'runs'} } }
tree = Tree(d)

print(d['foo']['amy']['what']) # returns 'runs'
d['foo']['amy']['when'] = 'now' # add new branch

In this way, you can keep edit/add/remove each dict level as you wish. All the dict methods for traversal etc, still apply.

How to get array keys in Javascript?

I wrote a function what works fine with every instance of Objects (Arrays are those).

Object.prototype.toArray = function()
{
    if(!this)
    {
      return null;
    }

    var c = [];

    for (var key in this) 
    {
        if ( ( this instanceof Array && this.constructor === Array && key === 'length' ) || !this.hasOwnProperty(key) ) 
        {
            continue;
        }

        c.push(this[key]);
    }

    return c;
};

Usage:

var a   = [ 1, 2, 3 ];
a[11]   = 4;
a["js"] = 5;

console.log(a.toArray());

var b = { one: 1, two: 2, three: 3, f: function() { return 4; }, five: 5 };
b[7] = 7;

console.log(b.toArray());

Output:

> [ 1, 2, 3, 4, 5 ]
> [ 7, 1, 2, 3, function () { return 4; }, 5 ]

It may be useful for anyone.

How to update value of a key in dictionary in c#?

Dictionary is a key value pair. Catch Key by

dic["cat"] 

and assign its value like

dic["cat"] = 5

Angular 2 Sibling Component Communication

Shared service is a good solution for this issue. If you want to store some activity information too, you can add Shared Service to your main modules (app.module) provider list.

@NgModule({
    imports: [
        ...
    ],
    bootstrap: [
        AppComponent
    ],
    declarations: [
        AppComponent,
    ],
    providers: [
        SharedService,
        ...
    ]
});

Then you can directly provide it to your components,

constructor(private sharedService: SharedService)
 

With Shared Service you can either use functions or you can create a Subject to update multiple places at once.

@Injectable()
export class SharedService {
    public clickedItemInformation: Subject<string> = new Subject(); 
}

In your list component you can publish clicked item information,

this.sharedService.clikedItemInformation.next("something");

and then you can fetch this information at your detail component:

this.sharedService.clikedItemInformation.subscribe((information) => {
    // do something
});

Obviously, the data that list component shares can be anything. Hope this helps.

pandas dataframe columns scaling with sklearn

(Tested for pandas 1.0.5)
Based on @athlonshi answer (it had ValueError: could not convert string to float: 'big', on C column), full working example without warning:

import pandas as pd
from sklearn.preprocessing import MinMaxScaler
scale = preprocessing.MinMaxScaler()

df = pd.DataFrame({
           'A':[14.00,90.20,90.95,96.27,91.21],
           'B':[103.02,107.26,110.35,114.23,114.68], 
           'C':['big','small','big','small','small']
         })
print(df)
df[["A","B"]] = pd.DataFrame(scale.fit_transform(df[["A","B"]].values), columns=["A","B"], index=df.index)
print(df)

       A       B      C
0  14.00  103.02    big
1  90.20  107.26  small
2  90.95  110.35    big
3  96.27  114.23  small
4  91.21  114.68  small
          A         B      C
0  0.000000  0.000000    big
1  0.926219  0.363636  small
2  0.935335  0.628645    big
3  1.000000  0.961407  small
4  0.938495  1.000000  small

Removing special characters VBA Excel

This is what I use, based on this link

Function StripAccentb(RA As Range)

Dim A As String * 1
Dim B As String * 1
Dim i As Integer
Dim S As String
'Const AccChars = "ŠŽšžŸÀÁÂÃÄÅÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖÙÚÛÜÝàáâãäåçèéêëìíîïðñòóôõöùúûüýÿ"
'Const RegChars = "SZszYAAAAAACEEEEIIIIDNOOOOOUUUUYaaaaaaceeeeiiiidnooooouuuuyy"
Const AccChars = "ñéúãíçóêôöá" ' using less characters is faster
Const RegChars = "neuaicoeooa"
S = RA.Cells.Text
For i = 1 To Len(AccChars)
A = Mid(AccChars, i, 1)
B = Mid(RegChars, i, 1)
S = Replace(S, A, B)
'Debug.Print (S)
Next


StripAccentb = S

Exit Function
End Function

Usage:

=StripAccentb(B2) ' cell address

Sub version for all cells in a sheet:

Sub replacesub()
Dim A As String * 1
Dim B As String * 1
Dim i As Integer
Dim S As String
Const AccChars = "ñéúãíçóêôöá" ' using less characters is faster
Const RegChars = "neuaicoeooa"
Range("A1").Resize(Cells.Find(what:="*", SearchOrder:=xlRows, _
SearchDirection:=xlPrevious, LookIn:=xlValues).Row, _
Cells.Find(what:="*", SearchOrder:=xlByColumns, _
SearchDirection:=xlPrevious, LookIn:=xlValues).Column).Select '
For Each cell In Selection
If cell <> "" Then
S = cell.Text
    For i = 1 To Len(AccChars)
    A = Mid(AccChars, i, 1)
    B = Mid(RegChars, i, 1)
    S = replace(S, A, B)
    Next
cell.Value = S
Debug.Print "celltext "; (cell.Text)
End If
Next cell
End Sub

Angular2 module has no exported member

This error can also occur if your interface name is different than the file it is contained in. Read about ES6 modules for details. If the SignInComponent was an interface, as was in my case, then

SignInComponent

should be in a file named SignInComponent.ts.

NSNotificationCenter addObserver in Swift

It's the same as the Objective-C API, but uses Swift's syntax.

Swift 4.2 & Swift 5:

NotificationCenter.default.addObserver(
    self,
    selector: #selector(self.batteryLevelChanged),
    name: UIDevice.batteryLevelDidChangeNotification,
    object: nil)

If your observer does not inherit from an Objective-C object, you must prefix your method with @objc in order to use it as a selector.

@objc private func batteryLevelChanged(notification: NSNotification){     
    //do stuff using the userInfo property of the notification object
}

See NSNotificationCenter Class Reference, Interacting with Objective-C APIs

If statements for Checkboxes

I suggest

if (checkbox.IsChecked == true)
{
    //do something
}

Hope it's helpful ^^

"date(): It is not safe to rely on the system's timezone settings..."

I had this error running php-fpm in a chroot jail. I tried creating etc/php.ini and /usr/share/zoneinfo in the chroot directory, but it just didn't work. I even tried strace-ing the php-fpm daemons to see what file they were missing - nothing jumped out.

So in case Google brings you here because you get this error when using php-fpm configured for chroot, you can probably fix it by adding this line to /etc/php-fpm.d/www.conf in the ENV section:

env[TZ] = America/New_York

A php-fpm restart is normally required for it to take effect. Hope this helps somebody out there.

Avoid duplicates in INSERT INTO SELECT query in SQL Server

A little off topic, but if you want to migrate the data to a new table, and the possible duplicates are in the original table, and the column possibly duplicated is not an id, a GROUP BY will do:

INSERT INTO TABLE_2
(name)
  SELECT t1.name
  FROM TABLE_1 t1
  GROUP BY t1.name

Remove unwanted parts from strings in a column

In the particular case where you know the number of positions that you want to remove from the dataframe column, you can use string indexing inside a lambda function to get rid of that parts:

Last character:

data['result'] = data['result'].map(lambda x: str(x)[:-1])

First two characters:

data['result'] = data['result'].map(lambda x: str(x)[2:])

Remove all subviews?

Edit: With thanks to cocoafan: This situation is muddled up by the fact that NSView and UIView handle things differently. For NSView (desktop Mac development only), you can simply use the following:

[someNSView setSubviews:[NSArray array]];

For UIView (iOS development only), you can safely use makeObjectsPerformSelector: because the subviews property will return a copy of the array of subviews:

[[someUIView subviews]
 makeObjectsPerformSelector:@selector(removeFromSuperview)];

Thank you to Tommy for pointing out that makeObjectsPerformSelector: appears to modify the subviews array while it is being enumerated (which it does for NSView, but not for UIView).

Please see this SO question for more details.

Note: Using either of these two methods will remove every view that your main view contains and release them, if they are not retained elsewhere. From Apple's documentation on removeFromSuperview:

If the receiver’s superview is not nil, this method releases the receiver. If you plan to reuse the view, be sure to retain it before calling this method and be sure to release it as appropriate when you are done with it or after adding it to another view hierarchy.

How do I add a bullet symbol in TextView?

With Unicode we can do it easily,but if want to change color of bullet, I tried with colored bullet image and set it as drawable left and it worked

<TextView     
    android:text="Hello bullet"
    android:drawableLeft="@drawable/bulleticon" >
</TextView>

Create directories using make file

I've just come up with a fairly reasonable solution that lets you define the files to build and have directories be automatically created. First, define a variable ALL_TARGET_FILES that holds the file name of every file that your makefile will be build. Then use the following code:

define depend_on_dir
$(1): | $(dir $(1))

ifndef $(dir $(1))_DIRECTORY_RULE_IS_DEFINED
$(dir $(1)):
    mkdir -p $$@

$(dir $(1))_DIRECTORY_RULE_IS_DEFINED := 1
endif
endef

$(foreach file,$(ALL_TARGET_FILES),$(eval $(call depend_on_dir,$(file))))

Here's how it works. I define a function depend_on_dir which takes a file name and generates a rule that makes the file depend on the directory that contains it and then defines a rule to create that directory if necessary. Then I use foreach to call this function on each file name and eval the result.

Note that you'll need a version of GNU make that supports eval, which I think is versions 3.81 and higher.

Preventing scroll bars from being hidden for MacOS trackpad users in WebKit/Blink

Another good way of dealing with Lion's hidden scroll bars is to display a prompt to scroll down. It doesn't work with small scroll areas such as text fields but well with large scroll areas and keeps the overall style of the site. One site doing this is http://versusio.com, just check this example page and wait 1.5 seconds to see the prompt:

http://versusio.com/en/samsung-galaxy-nexus-32gb-vs-apple-iphone-4s-64gb

The implementation isn't hard but you have to take care, that you don't display the prompt when the user has already scrolled.

You need jQuery + Underscore and

$(window).scroll to check if the user already scrolled by himself,

_.delay() to trigger a delay before you display the prompt -- the prompt shouldn't be to obtrusive

$('#prompt_div').fadeIn('slow') to fade in your prompt and of course

$('#prompt_div').fadeOut('slow') to fade out when the user scrolled after he saw the prompt

In addition, you can bind Google Analytics events to track user's scrolling behavior.

How do I mock an autowired @Value field in Spring with Mockito?

You can use this magic Spring Test annotation :

@TestPropertySource(properties = { "my.spring.property=20" }) 

see org.springframework.test.context.TestPropertySource

For example, this is the test class :

@ContextConfiguration(classes = { MyTestClass.Config.class })
@TestPropertySource(properties = { "my.spring.property=20" })
public class MyTestClass {

  public static class Config {
    @Bean
    MyClass getMyClass() {
      return new MyClass ();
    }
  }

  @Resource
  private MyClass myClass ;

  @Test
  public void myTest() {
   ...

And this is the class with the property :

@Component
public class MyClass {

  @Value("${my.spring.property}")
  private int mySpringProperty;
   ...

Excel formula to display ONLY month and year?

There are a number of ways to go about this. One way would be to enter the date 8/1/2013 manually in the first cell (say A1 for example's sake) and then in B1 type the following formula (and then drag it across):

=DATE(YEAR(A1),MONTH(A1)+1,1)

Since you only want to see month and year, you can format accordingly using the different custom date formats available.

The format you're looking for is YY-Mmm.

Merge data frames based on rownames in R

See ?merge:

the name "row.names" or the number 0 specifies the row names.

Example:

R> de <- merge(d, e, by=0, all=TRUE)  # merge by row names (by=0 or by="row.names")
R> de[is.na(de)] <- 0                 # replace NA values
R> de
  Row.names   a   b   c   d   e   f   g   h   i  j  k  l  m  n  o  p  q  r  s
1         1 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10 11 12 13 14 15 16 17 18 19
2         2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9  1  0  0  0  0  0  0  0  0  0
3         3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0  0 21 22 23 24 25 26 27 28 29
   t
1 20
2  0
3 30

When to use RabbitMQ over Kafka?

The only benefit that I can think of is Transactional feature, rest all can be done by using Kafka

Watermark / hint text / placeholder TextBox

Set up the text box with placeholder text in a soft color...

public MainWindow ( )
{
    InitializeComponent ( );
    txtInput.Text = "Type something here...";
    txtInput.Foreground = Brushes.DimGray;
}

When the text box gets the focus, clear it and change the text color

private void txtInput_GotFocus ( object sender, EventArgs e )
{
    MessageBox.Show ( "got focus" );
    txtInput.Text = "";
    txtInput.Foreground = Brushes.Red;
}

Windows service with timer

First approach with Windows Service is not easy..

A long time ago, I wrote a C# service.

This is the logic of the Service class (tested, works fine):

namespace MyServiceApp
{
    public class MyService : ServiceBase
    {
        private System.Timers.Timer timer;

        protected override void OnStart(string[] args)
        {
            this.timer = new System.Timers.Timer(30000D);  // 30000 milliseconds = 30 seconds
            this.timer.AutoReset = true;
            this.timer.Elapsed += new System.Timers.ElapsedEventHandler(this.timer_Elapsed);
            this.timer.Start();
        }

        protected override void OnStop()
        {
            this.timer.Stop();
            this.timer = null;
        }

        private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            MyServiceApp.ServiceWork.Main(); // my separate static method for do work
        }

        public MyService()
        {
            this.ServiceName = "MyService";
        }

        // service entry point
        static void Main()
        {
            System.ServiceProcess.ServiceBase.Run(new MyService());
        }
    }
}

I recommend you write your real service work in a separate static method (why not, in a console application...just add reference to it), to simplify debugging and clean service code.

Make sure the interval is enough, and write in log ONLY in OnStart and OnStop overrides.

Hope this helps!

input checkbox true or checked or yes

Only checked and checked="checked" are valid. Your other options depend on error recovery in browsers.

checked="yes" and checked="true" are particularly bad as they imply that checked="no" and checked="false" will set the default state to be unchecked … which they will not.

How To Set A JS object property name from a variable

jsonVariable = {}
for(i=1; i<3; i++) {        
   var jsonKey  = i+'name';
   jsonVariable[jsonKey] = 'name1'
}

this will be similar to

    jsonVariable = {
    1name : 'name1'
    2name : 'name1'
}

AngularJS toggle class using ng-class

<div data-ng-init="featureClass=false" 
     data-ng-click="featureClass=!featureClass" 
     data-ng-class="{'active': featureClass}">
    Click me to toggle my class!
</div>

Analogous to jQuery's toggleClass method, this is a way to toggle the active class on/off when the element is clicked.

How to undo a git merge with conflicts

Sourcetree

If you not commit your merge, then just double click on another branch (=checkout) and when sourcetree ask you about discarding all changes then agree

How can I use UserDefaults in Swift?

In class A, set value for key:

let text = "hai"  
UserDefaults.standard.setValue(text, forKey: "textValue")

In class B, get the value for the text using the key which declared in class A and assign it to respective variable which you need:

var valueOfText  = UserDefaults.value(forKey: "textValue")

XML Schema minOccurs / maxOccurs default values

The default values for minOccurs and maxOccurs are 1. Thus:

<xsd:element minOccurs="1" name="asdf"/>

cardinality is [1-1] Note: if you specify only minOccurs attribute, it can't be greater than 1, because the default value for maxOccurs is 1.

<xsd:element minOccurs="5" maxOccurs="2" name="asdf"/>

invalid

<xsd:element maxOccurs="2" name="asdf"/>

cardinality is [1-2] Note: if you specify only maxOccurs attribute, it can't be smaller than 1, because the default value for minOccurs is 1.

<xsd:element minOccurs="0" maxOccurs="0"/>

is a valid combination which makes the element prohibited.

For more info see http://www.w3.org/TR/xmlschema-0/#OccurrenceConstraints

One line if/else condition in linux shell scripting

To summarize the other answers, for general use:

Multi-line if...then statement

if [ foo ]; then
    a; b
elif [ bar ]; then
    c; d
else
    e; f
fi

Single-line version

if [ foo ]; then a && b; elif [ bar ]; c && d; else e && f; fi

Using the OR operator

( foo && a && b ) || ( bar && c && d ) || e && f;

Notes

Remember that the AND and OR operators evaluate whether or not the result code of the previous operation was equal to true/success (0). So if a custom function returns something else (or nothing at all), you may run into problems with the AND/OR shorthand. In such cases, you may want to replace something like ( a && b ) with ( [ a == 'EXPECTEDRESULT' ] && b ), etc.

Also note that ( and [ are technically commands, so whitespace is required around them.

Instead of a group of && statements like then a && b; else, you could also run statements in a subshell like then $( a; b ); else, though this is less efficient. The same is true for doing something like result1=$( foo; a; b ); result2=$( bar; c; d ); [ "$result1" -o "$result2" ] instead of ( foo && a && b ) || ( bar && c && d ). Though at that point you'd be getting more into less-compact, multi-line stuff anyway.

Commenting out code blocks in Atom

Atom does not have a specific comment-block function, but if you select more rows and then use the normal ctrl-/ (Windows or Linux) cmd-/ (Mac), it will comment all the lines.

Incrementing a date in JavaScript

Not entirelly sure if it is a BUG(Tested Firefox 32.0.3 and Chrome 38.0.2125.101), but the following code will fail on Brazil (-3 GMT):

Date.prototype.shiftDays = function(days){    
  days = parseInt(days, 10);
  this.setDate(this.getDate() + days);
  return this;
}

$date = new Date(2014, 9, 16,0,1,1);
$date.shiftDays(1);
console.log($date+"");
$date.shiftDays(1);
console.log($date+"");
$date.shiftDays(1);
console.log($date+"");
$date.shiftDays(1);
console.log($date+"");

Result:

Fri Oct 17 2014 00:01:01 GMT-0300
Sat Oct 18 2014 00:01:01 GMT-0300
Sat Oct 18 2014 23:01:01 GMT-0300
Sun Oct 19 2014 23:01:01 GMT-0200

Adding one Hour to the date, will make it work perfectly (but does not solve the problem).

$date = new Date(2014, 9, 16,0,1,1);

Result:

Fri Oct 17 2014 01:01:01 GMT-0300
Sat Oct 18 2014 01:01:01 GMT-0300
Sun Oct 19 2014 01:01:01 GMT-0200
Mon Oct 20 2014 01:01:01 GMT-0200

Why use HttpClient for Synchronous Connection

but what i am doing is purely synchronous

You could use HttpClient for synchronous requests just fine:

using (var client = new HttpClient())
{
    var response = client.GetAsync("http://google.com").Result;

    if (response.IsSuccessStatusCode)
    {
        var responseContent = response.Content; 

        // by calling .Result you are synchronously reading the result
        string responseString = responseContent.ReadAsStringAsync().Result;

        Console.WriteLine(responseString);
    }
}

As far as why you should use HttpClient over WebRequest is concerned, well, HttpClient is the new kid on the block and could contain improvements over the old client.

C# equivalent to Java's charAt()?

You can index into a string in C# like an array, and you get the character at that index.

Example:

In Java, you would say

str.charAt(8);

In C#, you would say

str[8];

Difference between /res and /assets directories

I know this is old, but just to make it clear, there is an explanation of each in the official android documentation:

from http://developer.android.com/tools/projects/index.html

assets/

This is empty. You can use it to store raw asset files. Files that you save here are compiled into an .apk file as-is, and the original filename is preserved. You can navigate this directory in the same way as a typical file system using URIs and read files as a stream of bytes using the AssetManager. For example, this is a good location for textures and game data.

res/raw/

For arbitrary raw asset files. Saving asset files here instead of in the assets/ directory only differs in the way that you access them. These files are processed by aapt and must be referenced from the application using a resource identifier in the R class. For example, this is a good place for media, such as MP3 or Ogg files.

How does the vim "write with sudo" trick work?

:w - Write a file.

!sudo - Call shell sudo command.

tee - The output of write (vim :w) command redirected using tee. The % is nothing but current file name i.e. /etc/apache2/conf.d/mediawiki.conf. In other words tee command is run as root and it takes standard input and write it to a file represented by %. However, this will prompt to reload file again (hit L to load changes in vim itself):

tutorial link