Tutorial by Examples

Filters allows you to apply a function to a variable. This function may take 0 or 1 argument. Here is the syntax: {{ variable|filter_name }} {{ variable|filter_name:argument }} Filters can be chained so this is perfectly valid: {{ variable|filter_name:argument|another_filter }} If transla...

The simplest way of defining a custom template tag is to use a simple_tag. These are very straightforward to setup. The function name will be the tag name (though you can override it), and arguments will be tokens ("words" separated by spaces, except spaces enclosed between quotes). It eve...

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...

Remove all characters except digits, plus and minus sign. var_dump(filter_var(1, FILTER_SANITIZE_NUMBER_INT)); var_dump(filter_var(-1, FILTER_SANITIZE_NUMBER_INT)); var_dump(filter_var(+1, FILTER_SANITIZE_NUMBER_INT)); var_dump(filter_var(1.00, FILTER_SANITIZE_NUMBER_INT)); var_dump(filter_var(...

Sanitze URLs Remove all characters except letters, digits and $-_.+!*'(),{}|\^~[]`<>#%";/?:@&= var_dump(filter_var('http://www.example.com/path/to/dir/index.php?test=y', FILTER_SANITIZE_URL)); var_dump(filter_var("http://www.example.com/path/to/dir/index.php?test=y!#$%&'*+...

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...

The process.env property returns an object containing the user environment. It returns an object like this one : { TERM: 'xterm-256color', SHELL: '/usr/local/bin/bash', USER: 'maciej', PATH: '~/.bin/:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin', PWD: '/Users/maciej', EDITOR: 'vi...

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 ...

Interfaces should be named with nouns or noun phrases, or adjectives that describe behaviour. For example IComponent uses a descriptive noun, ICustomAttributeProvider uses a noun phrase and IPersistable uses an adjective. Interface names should be prefixed with the letter I, to indicate that the ty...

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 ...

An iterable is an object that can return an iterator. Any object with state that has an __iter__ method and returns an iterator is an iterable. It may also be an object without state that implements a __getitem__ method. - The method can take indices (starting from zero) and raise an IndexError whe...

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...