How to inject dependencies into a provider using Angularjs?

Question

Is it possible to do DI in a provider method?

In this example

angular.module('greet',[]) .provider('greeter',function() {    this.$get=function() {    }; }) .service('greeterService',function($http){   console.log($http); }) ; 

Injecting $http into service appears to be the correct implementation, but it doesn't work in a provider method and it throws an error:

Unknown provider: $http

Does the provider method work with DI to inject services?

Answer 1

You can certainly inject $http to provider. Just make sure it appears in $get, not the function constructor. As follows:

angular.module('greet',[]).provider('greeter',function() {   this.$get = function($http) {    }; }); 

Answer 2

You can inject constants and other providers into a provider. Not services or factories - with one exception. It seems that you can inject the $injector service into a provider - at least, you can in AngularJS 1.3.16.

.provider('foo', ['$injector', function ($injector) {   var messagePrefix = $injector.get('msgPrefix');   this.message = '';    this.$get = function() {     var that = this;     return function() {       return messagePrefix + that.message;     }   }; }]) 

You can use the injector outside the $get method, but you still can't get services from it at configure time.

See here for a demo.