This is an example to show how to change the allowed choices on a subCategory select field depending on the value of the category select field.
To do that you have to make your subCategory choices dynamical for both client and server side.
1. Make the form dynamic on the client side for display / ...
Qt provides a deployment tool for Windows: windeployqt. The tool inspects a Qt application executable for its dependecies to Qt modules and creates a deployment directory with the necessary Qt files to run the inspected executable. A possible script may look like:
set PATH=%PATH%;<qt_install_pre...
BEGIN TRY -- start error handling
BEGIN TRANSACTION; -- from here on transactions (modifictions) are not final
-- start your statement(s)
select 42/0 as ANSWER -- simple SQL Query with an error
-- end your statement(s)
COMMIT TRANSACTION; -- finalize all transa...
The first thing we need is to tell karma to use Webpack to read our tests, under a configuration we set for the webpack engine. Here, I am using babel because I write my code in ES6, you can change that for other flavors, such as Typescript. Or I use Pug (formerly Jade) templates, you don't have to....
Getting a reference to the main bundle using Cocoa.
To get the main bundle in Cocoa application, call the mainBundle class method of the NSBundle class.
NSBundle *mainBundle;
// Get the main bundle for the app;
mainBundle = [NSBundle mainBundle];
Getting a reference to ...
Locating a Cocoa bundle using its path
To obtain the bundle at a specific path using Cocoa, call the bundleWithPath: class method of the NSBundle
NSBundle *myBundle;
// obtain a reference to a loadable bundle
myBundle = [NSBundle bundleWithPath:@"/Library/MyBundle.bundle...
Before reading and writing text files you should know what encoding to use. See the Perl Unicode Documentation for more details on encoding. Here we show the setting of UTF-8 as the default encoding and decoding for the function open. This is done by using the open pragma near the top of your code (...
SELECT 1,22,44
UNION
SELECT 2,33,55
SELECT 1,22,44
UNION
SELECT 2,33,55
UNION
SELECT 2,33,55
The result is the same as above.
use UNION ALL
when
SELECT 1,22,44
UNION
SELECT 2,33,55
UNION ALL
SELECT 2,33,55
The Maven Surefire plugin runs during the test phase of the Maven build process or when test is specified as a Maven goal. The following directory structure and minimum pom.xml file will configure Maven to run a test.
Directory structure inside the project's root directory:
─ project_root
├─ p...
Most of linux distros stores its version info in the /etc/lsb-release (debian) or /etc/redhat-release (RPM based) file. Using below generic command should get you past most of the Debian and RPM derivatives as Linux Mint and Cent-Os.
Example on Ubuntu Machine:
cat /etc/*release
DISTRIB_ID=Ubuntu
...
The sample content used here is Tears of Steel, by Blender Foundation. Specifically, we will use the download titled "HD 720p (~365MB, mov, 2.0)". This is a single file that ends with the extension "mov" and will play in just about any modern media player.
Note that the download...
This example will explore how to see the layout of a video track and how to extract the individual pictures within it.
The sample content used here is Tears of Steel, by Blender Foundation. Specifically, we will use the download titled "HD 720p (~365MB, mov, 2.0)". This is a single file t...
DASH is the most widely deployed adaptive streaming technology in modern solutions, used to deliver video in a wide variety of scenarios. The best way to understand DASH presentations is to observe the network activity that takes place during playback.
This example uses Fiddler to capture and analy...
Mongoose connect has 3 parameters, uri, options, and the callback function. To use them see sample below.
var mongoose = require('mongoose');
var uri = 'mongodb://localhost:27017/DBNAME';
var options = {
user: 'user1',
pass: 'pass'
}
mongoose.connect(uri, options, function(err){...
I.Overview
A significant difference between MongoDB & RDBMS is MongoDB has many kinds of operators. One of them is update operator, which is used in update statements.
II.What happen if we don't use update operators?
Suppose we have a student collection to store student information(Table view...
JSON is a very strict format (see http://json.org). That makes it easy to parse and write for machines but surprises humans when an inconspicuous mistakes breaks the document.
Common Problems
Trailing Comma
Unlike most programming languages your are not allowed to add a trailing comma:
{
a: 1...
In order to send messages to the queue, we will write a C# console application using Visual Studio.
Create a console application
Launch Visual Studio and create a new Console application.
Add the Service Bus NuGet package
Right click on the newly created project and select Manage NuGet P...
Ionic has some CSS components where you can use Ionicons as a default which have preset styling. The range class in the item <div> will apply correct styling to both the input and the icons inside it. Here's an example of a range slider.
<div class="item range">
<i class...
A shader program, in the OpenGL sense, contains a number of different shaders. Any shader program must have at least a vertex shader, that calculates the position of the points on the screen, and a fragment shader, that calculates the colour of each pixel. (Actually the story is longer and more co...
Recursive use of make means using make as a command within a makefile. This technique is useful when a large project contains sub-directories, each having their respective makefiles. The following example will help understand advantage of using .PHONY with recursive make.
/main
|_ Makefile
...
