Service 和 Factory

Angular鼓励程序员来把业务逻辑和数据分开来写。

Service

app.service('MyService', function () {
  this.helloWorld = function () {
    console.log('Hello World');
  };
});

Factory

// The code below is a factory.
app.factory('MyService', function () {
  return {
    helloWorld: function () {
      console.log('Hello World');
    };
  }
});

通过上面的代码可以看出来，Service是一个constructor function，factory是一个函数。但实际上通过阅读源代码来看，Service也调用了Factory：

// By calling service() you are also calling a predefined factory() within AngularJs
function service(name, constructor) {
  return factory(name, ['$injector', function($injector) {
    return $injector.instantiate(constructor);
  }]);
}