View source Improve this doc

$filterProvider

service in module ng

Description

Filters are just functions which transform input to an output. However filters need to be Dependency Injected. To achieve this a filter definition consists of a factory function which is annotated with dependencies and is responsible for creating a filter function.

  1.   // Filter registration
  2.   function MyModule($provide, $filterProvider) {
  3.     // create a service to demonstrate injection (not always needed)
  4.     $provide.value('greet', function(name){
  5.       return 'Hello ' + name + '!';
  6.     });
  7.  
  8.     // register a filter factory which uses the
  9.     // greet service to demonstrate DI.
  10.     $filterProvider.register('greet', function(greet){
  11.       // return the filter function which uses the greet service
  12.       // to generate salutation
  13.       return function(text) {
  14.         // filters need to be forgiving so check input validity
  15.         return text && greet(text) || text;
  16.       };
  17.     });
  18.   }

The filter function is registered with the $injector under the filter name suffix with Filter.

  1.   it('should be the same instance', inject(
  2.     function($filterProvider) {
  3.       $filterProvider.register('reverse', function(){
  4.         return ...;
  5.       });
  6.     },
  7.     function($filter, reverseFilter) {
  8.       expect($filter('reverse')).toBe(reverseFilter);
  9.     });

For more information about how angular filters work, and how to create your own filters, see Filters in the Angular Developer Guide.

Methods

  • register(name, fn)

Register filter factory function.

Parameters

ParamTypeDetailsnameString

Name of the filter.

fnfunction

The filter factory function which is injectable.