如何扩展服务-howcaniextendaservice

21  

Your ExtendedServiceshould inject the BasicServicein order to be able to access it. Beside that BasicService is an object literal, so you can't actually call it as function (BasicService()).

您的ExtendedServiceshould注入BasicServicein以便能够访问它。在BasicService的旁边是一个对象文字，因此您不能实际地将它调用为function (BasicService())。

.factory('ExtendedService', function($http, BasicService){
  BasicService['method_four'] = function(){};
  return BasicService;
}

68  

More cleaner and imperative way

更干净、更迫切的方式

.factory('ExtendedService', function($http, BasicService){

    var extended = angular.extend(BasicService, {})
    extended.method = function() {
        // ...
    }
    return extended;
}

16  

In my opinion, a better way:

在我看来，更好的办法是:

.factory('ExtendedService', function($http, BasicService){
    var service = angular.copy(BasicService);

    service.methodFour = function(){
        //code for method four
    };

    return service;
});

Here at least does not change the inherited service.

这里至少不会更改继承的服务。

3  

Sorry if I post here but may be it's a good place to do it. I refer to this post

对不起，如果我在这里张贴，但可能是一个好地方。我指的是这篇文章

watch out to extend a service/factory because are singleton so you can extend a service/factory once.

注意扩展服务/工厂，因为是单例的，所以可以只扩展一次服务/工厂。

'use strict';
            angular.module('animal', [])
                .factory('Animal',function(){
                        return {
                            vocalization:'',
                            vocalize : function () {
                                console.log('vocalize: ' + this.vocalization);
                            }
                        }

                });
                angular.module('dog', ['animal'])
                    .factory('Dog', function (Animal) {
                        Animal.vocalization = 'bark bark!';
                        Animal.color = 'red';
                        return Animal;
                    });

                angular.module('cat', ['animal'])
                   .factory('Cat', function (Animal) {
                        Animal.vocalization = 'meowwww';
                        Animal.color = 'white';
                        return Animal;
                    });
                 angular.module('app', ['dog','cat'])
                .controller('MainCtrl',function($scope,Cat,Dog){
                     $scope.cat = Cat;
                     $scope.dog = Dog;
                     console.log($scope.cat);
                     console.log($scope.dog);
                    //$scope.cat = Cat;
                });

but if you do like

但如果你喜欢的话

'use strict';
            angular.module('animal', [])
                .factory('Animal',function(){
                    return function(vocalization){
                        return {
                            vocalization:vocalization,
                            vocalize : function () {
                                console.log('vocalize: ' + this.vocalization);
                            }
                        }
                    }
                });    
                angular.module('app', ['animal'])
                    .factory('Dog', function (Animal) {
                        function ngDog(){
                            this.prop = 'my prop 1';
                            this.myMethod = function(){
                                console.log('test 1');
                            }
                        }
                        return angular.extend(Animal('bark bark!'), new ngDog());
                    })
                    .factory('Cat', function (Animal) {
                        function ngCat(){
                            this.prop = 'my prop 2';
                            this.myMethod = function(){
                                console.log('test 2');
                            }
                        }
                        return angular.extend(Animal('meooow'), new ngCat());
                    })
                .controller('MainCtrl',function($scope,Cat,Dog){
                     $scope.cat = Cat;
                     $scope.dog = Dog;
                     console.log($scope.cat);
                     console.log($scope.dog);
                    //$scope.cat = Cat;
                });

it works

它的工作原理

1  

I wrote an $extend provider that uses Backbone's extend under the hood -- So you get both prototype and static property extending in case you need them -- Plus you get parent/child constructors -- see gist @ https://gist.github.com/asafebgi/5fabc708356ea4271f51

我编写了一个$extend提供程序，它使用了主干的扩展——如果需要的话，您可以获得原型和静态属性扩展——以及父/子构造函数——请参见gist @ https://gist.github.com/asafebgi/5fabc708356ea4271f51

-1  

To expand on Stewie's answer, you could also do the following:

要扩展Stewie的答案，你也可以做以下事情:

.factory('ExtendedService', function($http, BasicService){
    var service = {
        method_one: BasicService.method_one,
        method_two: BasicService.method_two,
        method_three: BasicService.method_three,
        method_four: method_four
    });

    return service ;

    function method_four(){

    }
}

This has the benefit that the original service is not altered, while keeping it's functionality. You can also choose to use your own implementations in the ExtendedService for the other 3 methods from BasicService.

这样做的好处是，原始服务不会被更改，同时保留它的功能。您还可以为BasicService的其他3个方法在ExtendedService中使用自己的实现。