Tutorial by Examples: ev

You can use a filter to log only messages "lower" than e.g. ERROR level. But the filter is not supported by PropertyConfigurator. So you must change to XML config to use it. See log4j-Wiki about filters. Example "specific level" <appender name="info-out" class=&quo...

In order to prevent a button from firing multiple times within a short period of time (let's say 2 clicks within 1 second, which may cause serious problems if the flow is not controlled), one can implement a custom SingleClickListener. This ClickListener sets a specific time interval as threshold (...

GRANT SELECT, UPDATE ON Employees TO User1, User2; Grant User1 and User2 permission to perform SELECT and UPDATE operations on table Employees. REVOKE SELECT, UPDATE ON Employees FROM User1, User2; Revoke from User1 and User2 the permission to perform SELECT and UPDATE operations on tab...

To install DevExpress .NET products on your development machine, it is first necessary to obtain the DevExpress .NET Products Installer. You can download it from the http://www.devexpress.com website in one of the following ways, based on the status of your current account. Download the Trial ...

tf.exe get /all /recursive /force /overwrite $/ Gets all files and directories, and will replace any files that are not currently checked out in the workspace (including files that have been edited).

This will get all the orders for all customers: SELECT c.CustomerName, o.OrderID FROM Customers AS c INNER JOIN Orders AS o ON c.CustomerID = o.CustomerID ORDER BY c.CustomerName, o.OrderID; This will count the number of orders for each customer: SELECT c.CustomerName, C...

In this example, we are going to create an image picker that previews your picture before uploading. The previewer also supports drag and dropping files into the input. In this example, I am only going to cover uploading single files, but you can tinker a bit to get multi file upload working. image...

To be able to use vim commands in Python, the vim module should be imported. :python import vim After having this module imported, the user has access to the command function: :python vim.command("normal iText to insert") This command would execute i in normal mode then type Text t...

Create drawable file named with custom_rectangle.xml in drawable folder: <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" > <solid android:color=&quo...

use Symfony\Component\EventDispatcher\EventDispatcher; use Symfony\Component\EventDispatcher\Event; use Symfony\Component\EventDispatcher\GenericEvent; // you may store this in a dependency injection container for use as a service $dispatcher = new EventDispatcher(); // you can attach liste...

use Symfony\Component\EventDispatcher\EventDispatcher; use Symfony\Component\EventDispatcher\EventSubscriberInterface; use Symfony\Component\EventDispatcher\Event; $dispatcher = new EventDispatcher(); // you can attach event subscribers, which allow a single object to subscribe // to many ...

Powershell allows multiple assignment of variables and treats almost everything like an array or list. This means that instead of doing something like this: $input = "foo.bar.baz" $parts = $input.Split(".") $foo = $parts[0] $bar = $parts[1] $baz = $parts[2] You can simply...

You can see list with all environment variables with: Get-Childitem env:

In order to begin using WebRTC you need to get camera and microphone permission.For that you need following things: adapter.js, you can get it from here A html webpage with a video tag and little bit of js code The adapter.js is a JavaScript shim for WebRTC, maintained by Google with help fro...

d3.js doesn't have a .off() method to detatch existent event listeners. In order to remove an event handler, you have to set it to null: d3.select('span').on('click', null)

You can access online help documentation using: Get-Help Get-Command -Online

Local variables - Those declared within a procedure (subroutine or function) of a class (or other structure). In this example, exampleLocalVariable is a local variable declared within ExampleFunction(): Public Class ExampleClass1 Public Function ExampleFunction() As Integer Dim exa...

CLISP has an integration with GNU Readline. For improvements for other implementations see: How to customize the SBCL REPL.

We can also specify that a virtual function is pure virtual (abstract), by appending = 0 to the declaration. Classes with one or more pure virtual functions are considered to be abstract, and cannot be instantiated; only derived classes which define, or inherit definitions for, all pure virtual fun...

// Store a reference to the native method let open = XMLHttpRequest.prototype.open; // Overwrite the native method XMLHttpRequest.prototype.open = function() { // Assign an event listener this.addEventListener("load", event => console.log(XHR), false); // Call the s...