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AngularJS API Reference auto auto/service auto/service/$injector auto/service/$provide ng ng/directive ng/directive/a ng/directive/form ng/directive/input ng/directive/input[checkbox] ng/directive/input[date] ng/directive/input[dateTimeLocal] ng/directive/input[email] ng/directive/input[month] ng/directive/input[number] ng/directive/input[radio] ng/directive/input[text] ng/directive/input[time] ng/directive/input[url] ng/directive/input[week] ng/directive/ngApp ng/directive/ngBind ng/directive/ngBindHtml ng/directive/ngBindTemplate ng/directive/ngBlur ng/directive/ngChange ng/directive/ngChecked ng/directive/ngClass ng/directive/ngClassEven ng/directive/ngClassOdd ng/directive/ngClick ng/directive/ngCloak ng/directive/ngController ng/directive/ngCopy ng/directive/ngCsp ng/directive/ngCut ng/directive/ngDblclick ng/directive/ngDisabled ng/directive/ngFocus ng/directive/ngForm ng/directive/ngHide ng/directive/ngHref ng/directive/ngIf ng/directive/ngInclude ng/directive/ngInit ng/directive/ngKeydown ng/directive/ngKeypress ng/directive/ngKeyup ng/directive/ngList ng/directive/ngModel ng/directive/ngModelOptions ng/directive/ngMousedown ng/directive/ngMouseenter ng/directive/ngMouseleave ng/directive/ngMousemove ng/directive/ngMouseover ng/directive/ngMouseup ng/directive/ngNonBindable ng/directive/ngOpen ng/directive/ngPaste ng/directive/ngPluralize ng/directive/ngReadonly ng/directive/ngRepeat ng/directive/ngSelected ng/directive/ngShow ng/directive/ngSrc ng/directive/ngSrcset ng/directive/ngStyle ng/directive/ngSubmit ng/directive/ngSwitch ng/directive/ngTransclude ng/directive/ngValue ng/directive/script ng/directive/select ng/directive/textarea ng/filter ng/filter/currency ng/filter/date ng/filter/filter ng/filter/json ng/filter/limitTo ng/filter/lowercase ng/filter/number ng/filter/orderBy ng/filter/uppercase ng/function ng/function/angular.bind ng/function/angular.bootstrap ng/function/angular.copy ng/function/angular.element ng/function/angular.equals ng/function/angular.extend ng/function/angular.forEach ng/function/angular.fromJson ng/function/angular.identity ng/function/angular.injector ng/function/angular.isArray ng/function/angular.isDate ng/function/angular.isDefined ng/function/angular.isElement ng/function/angular.isFunction ng/function/angular.isNumber ng/function/angular.isObject ng/function/angular.isString ng/function/angular.isUndefined ng/function/angular.lowercase ng/function/angular.module ng/function/angular.noop ng/function/angular.toJson ng/function/angular.uppercase ng/object ng/object/angular.version ng/provider ng/provider/$animateProvider ng/provider/$compileProvider ng/provider/$controllerProvider ng/provider/$filterProvider ng/provider/$httpProvider ng/provider/$interpolateProvider ng/provider/$locationProvider ng/provider/$logProvider ng/provider/$parseProvider ng/provider/$rootScopeProvider ng/provider/$sceDelegateProvider ng/provider/$sceProvider ng/service ng/service/$anchorScroll ng/service/$animate ng/service/$cacheFactory ng/service/$compile ng/service/$controller ng/service/$document ng/service/$exceptionHandler ng/service/$filter ng/service/$http ng/service/$httpBackend ng/service/$interpolate ng/service/$interval ng/service/$locale ng/service/$location ng/service/$log ng/service/$parse ng/service/$q ng/service/$rootElement ng/service/$rootScope ng/service/$sce ng/service/$sceDelegate ng/service/$templateCache ng/service/$timeout ng/service/$window ng/type ng/type/$cacheFactory.Cache ng/type/$compile.directive.Attributes ng/type/$rootScope.Scope ng/type/angular.Module ng/type/form.FormController ng/type/ngModel.NgModelController ngAnimate ngAnimate/provider ngAnimate/provider/$animateProvider ngAnimate/service ngAnimate/service/$animate ngCookies ngCookies/service ngCookies/service/$cookies ngCookies/service/$cookieStore ngMessages ngMessages/directive ngMessages/directive/ngMessage ngMessages/directive/ngMessages ngMock ngMock/function ngMock/function/angular.mock.dump ngMock/function/angular.mock.inject ngMock/function/angular.mock.module ngMock/object ngMock/object/angular.mock ngMock/provider ngMock/provider/$exceptionHandlerProvider ngMock/service ngMock/service/$exceptionHandler ngMock/service/$httpBackend ngMock/service/$interval ngMock/service/$log ngMock/service/$timeout ngMock/type ngMock/type/angular.mock.TzDate ngMockE2E ngMockE2E/service ngMockE2E/service/$httpBackend ngResource ngResource/service ngResource/service/$resource ngRoute ngRoute/directive ngRoute/directive/ngView ngRoute/provider ngRoute/provider/$routeProvider ngRoute/service ngRoute/service/$route ngRoute/service/$routeParams ngSanitize ngSanitize/filter ngSanitize/filter/linky ngSanitize/service ngSanitize/service/$sanitize ngTouch ngTouch/directive ngTouch/directive/ngClick ngTouch/directive/ngSwipeLeft ngTouch/directive/ngSwipeRight ngTouch/service ngTouch/service/$swipe
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AngularJS: API: auto/service/$injector


$injector

  1. - service in module auto

$injector is used to retrieve object instances as defined by Provider, instantiate types, invoke methods, and load modules.

The following always holds true:

  var $injector = angular.injector();
  expect($injector.get('$injector')).toBe($injector);
  expect($injector.invoke(Function($injector){
    return $injector;
  }).toBe($injector);

Injection Function Annotation

JavaScript does not have annotations, and annotations are needed for 依赖注入. The following are all valid ways of annotating function with injection arguments and are equivalent.

  // inferred (only works if code not minified/obfuscated)
  $injector.invoke(Function(serviceA){});

  // annotated
  Function explicit(serviceA) {};
  explicit.$inject = ['serviceA'];
  $injector.invoke(explicit);

  // inline
  $injector.invoke(['serviceA', Function(serviceA){}]);

Inference

In JavaScript calling toString() on a function returns the function definition. The definition can then be parsed and the function arguments can be extracted. 注意: This does not work with minification, and obfuscation tools since these tools change the argument names.

$inject Annotation

By adding an $inject property onto a function the injection parameters can be specified.

Inline

As an array of injection names, where the last item in the array is the function to call.

用法

$injector();

方法

  • get(名称);

    Return an instance of the service.

    参数

    参数 类型 详述
    name string

    The name of the instance to retrieve.

    返回值

    *

    The instance.

  • invoke(fn, [self], [locals]);

    Invoke the method and supply the method arguments from the $injector.

    参数

    参数 类型 详述
    fn !Function

    The function to invoke. Function parameters are injected according to the $inject Annotation rules.

    self
    (可选)
    Object

    The this for the invoked method.

    locals
    (可选)
    Object

    Optional object. If preset then any argument names are read from this object first, before the $injector is consulted.

    返回值

    *

    the value returned by the invoked fn function.

  • has(名称);

    Allows the user to query if the particular service exists.

    参数

    参数 类型 详述
    Name string

    of the service to query.

    返回值

    boolean

    returns true if injector has given service.

  • instantiate(Type, [locals]);

    Create a new instance of JS type. The method takes a constructor function, invokes the new operator, and supplies all of the arguments to the constructor function as specified by the constructor annotation.

    参数

    参数 类型 详述
    Type Function

    Annotated constructor function.

    locals
    (可选)
    Object

    Optional object. If preset then any argument names are read from this object first, before the $injector is consulted.

    返回值

    Object

    new instance of Type.

  • annotate(fn);

    Returns an array of service names which the function is requesting for injection. This API is used by the injector to determine which services need to be injected into the function when the function is invoked. There are three ways in which the function can be annotated with the needed dependencies.

    Argument names

    The simplest form is to extract the dependencies from the arguments of the function. This is done by converting the function into a string using toString() method and extracting the argument names.

      // Given
      Function MyController($scope, $route) {
        // ...
      }
    
      // Then
      expect(injector.annotate(MyController)).toEqual(['$scope', '$route']);

    This method does not work with code minification / obfuscation. For this reason the following annotation strategies are supported.

    The $inject property

    If a function has an $inject property and its value is an array of strings, then the strings represent names of services to be injected into the function.

      // Given
      var MyController = Function(obfuscatedScope, obfuscatedRoute) {
        // ...
      }
      // Define function dependencies
      MyController['$inject'] = ['$scope', '$route'];
    
      // Then
      expect(injector.annotate(MyController)).toEqual(['$scope', '$route']);

    The array notation

    It is often desirable to inline Injected functions and that's when setting the $inject property is very inconvenient. In these situations using the array notation to specify the dependencies in a way that survives minification is a better choice:

      // We wish to write this (not minification / obfuscation safe)
      injector.invoke(Function($compile, $rootScope) {
        // ...
      });
    
      // We are forced to write break inlining
      var tmpFn = Function(obfuscatedCompile, obfuscatedRootScope) {
        // ...
      };
      tmpFn.$inject = ['$compile', '$rootScope'];
      injector.invoke(tmpFn);
    
      // To better support inline function the inline annotation is supported
      injector.invoke(['$compile', '$rootScope', Function(obfCompile, obfRootScope) {
        // ...
      }]);
    
      // Therefore
      expect(injector.annotate(
         ['$compile', '$rootScope', Function(obfus_$compile, obfus_$rootScope) {}])
       ).toEqual(['$compile', '$rootScope']);

    参数

    参数 类型 详述
    fn function()Array.<(string|function())>

    Function for which dependent service names need to be retrieved as described above.

    返回值

    Array.<string>

    The names of the services which the function requires.


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