Tutorial by Examples: d

Returns the first element that matches the selector starting at the element and traversing up the DOM tree. HTML <div id="abc" class="row"> <div id="xyz" class="row"> </div> <p id="origin"> Hello &...

There are three types of comment: # This comment continues to the end of line -- This comment continues to the end of line /* This is an in-line comment */ /* This is a multiple-line comment */ Example: SELECT * FROM t1; -- this is comment CREATE TABLE stack( /*id_user int...

Sometimes what you want to do is just too complex for a filter or a simple_tag. Fow this you will need to create a compilation function and a renderer. In this example we will create a template tag verbose_name with the following syntax: ExampleDescription{% verbose_name obj %}Verbose name of a mo...

superman-directive.js angular.module('myApp', []) .directive('superman', function() { return { // restricts how the directive can be used restrict: 'E', templateUrl: 'superman-template.html', controller: function() { this.message = "I'm superman!&qu...

var_dump(filter_var(true, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE)); // true var_dump(filter_var(false, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE)); // false var_dump(filter_var(1, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE)); // true var_dump(filter_var(0, FILTER_VALIDATE_BOOL...

Validates value as float, and converts to float on success. var_dump(filter_var(1, FILTER_VALIDATE_FLOAT)); var_dump(filter_var(1.0, FILTER_VALIDATE_FLOAT)); var_dump(filter_var(1.0000, FILTER_VALIDATE_FLOAT)); var_dump(filter_var(1.00001, FILTER_VALIDATE_FLOAT)); var_dump(filter_var('1', FILTE...

Validates a value is a valid MAC address var_dump(filter_var('FA-F9-DD-B2-5E-0D', FILTER_VALIDATE_MAC)); var_dump(filter_var('DC-BB-17-9A-CE-81', FILTER_VALIDATE_MAC)); var_dump(filter_var('96-D5-9E-67-40-AB', FILTER_VALIDATE_MAC)); var_dump(filter_var('96-D5-9E-67-40', FILTER_VALIDATE_MAC)); v...

Remove all characters except letters, digits and !#$%&'*+-=?^_`{|}~@.[]. var_dump(filter_var('[email protected]', FILTER_SANITIZE_EMAIL)); var_dump(filter_var("!#$%&'*+-=?^_`{|}~.[]@example.com", FILTER_SANITIZE_EMAIL)); var_dump(filter_var('john/@example.com', FILTER_SANITIZE_EM...

Declare your interface with Retrofit2 annotations: public interface BackendApiClient { @Multipart @POST("/uploadFile") Call<RestApiDefaultResponse> uploadPhoto(@Part("file\"; filename=\"photo.jpg\" ") RequestBody photo); } Where RestApiDef...

After launching Visual Studio 2015, go to File → New → Project. In the New Project dialog box, browse in the templates tree to Visual C# → Windows → Universal and select Blank App (Universal Windows). Next, we need to fill the form to describe the Application: Name: this is the name of the appli...

If IPython (or Jupyter) are installed, the debugger can be invoked using: import ipdb ipdb.set_trace() When reached, the code will exit and print: /home/usr/ook.py(3)<module>() 1 import ipdb 2 ipdb.set_trace() ----> 3 print("Hello world!") ipdb> Clea...

Spacemacs is a distribution of emacs that comes with a lot of packages preconfigured and easily installed. Also, it is very friendly for those who are familiar with vim style of editing. Spacemacs provides a CIDER-based Clojure layer. To install and configure it for use with Clojure, first install ...

Backpressure is when in an Observable processing pipeline, some asynchronous stages can't process the values fast enough and need a way to tell the upstream producer to slow down. The classic case of the need for backpressure is when the producer is a hot source: PublishSubject<Integer> sour...

<p ng-bind="message"></p> This 'message' has to be attached to the current elements controller's scope. $scope.message = "Hello World"; At a later point of time , even if the message model is updated , that updated value is reflected in the HTML element. When ...

As well as allowing module entities to have access control (being public or private) modules entities may also have the protect attribute. A public protected entity may be use associated, but the used entity is subject to restrictions on its use. module mod integer, public, protected :: i=1 en...

Asynchronously var fs = require('fs'); fs.stat('path/to/file', function(err) { if (!err) { console.log('file or directory exists'); } else if (err.code === 'ENOENT') { console.log('file or directory does not exist'); } }); Synchronously here, we must wr...

The most important application events are: Application_Start - It is raised when the application/website is started. Application_End - It is raised when the application/website is stopped. Similarly, the most used Session events are: Session_Start - It is raised when a user first requests a page...

Common page and control events are: DataBinding - It is raised when a control binds to a data source. Disposed - It is raised when the page or the control is released. Error - It is a page event, occurs when an unhandled exception is thrown. Init - It is raised when the page or the control is in...

The default event for the Page object is Load event. Similarly, every control has a default event. For example, default event for the button control is the Click event. The default event handler could be created in Visual Studio, just by double clicking the control in design view. The following tab...

Laravel allows user work on multiple database connections. If you need to connect to multiple databases and make them work together, you are beware of the connection setup. You also allow using different types of database in the same application if you required. Default connection In config/dat...