角服务返回对象？

Question

As far as I understand Angularjs services are created by passing in a Contructor function:

app.service('serviceName', function(){
  this.var1 = 'foo';

  this.method1 =  function(){

   }
});

Angular runs this function with the operator.

I was going through this service, and i don't see any "this" insider

https://github.com/shreya5/angular-facebook-utils/blob/master/src/scripts/facebookUser.js

Infact this function returns

Can someone shed some light on what's going on here ?

Answer 1

You are free to choose whatever pattern you want. Just because angular runs your function with new doesn't obligate you to use this nor does it require you to return the default object.

For example, this is a pretty nice idiom that I use in Angular services a lot:

function myConstructor(me){  
    me = me || "Mark";
    return {
        name: me,
        sayit: function(){return "Say my name, " + me}
     };

 }
 var obj = new myConstructor("Steve");
 console.log(obj.sayit())
 console.log(obj.name)

Answer 2

The value returned from service depends on how it will be used. You are free to return whatever you want. From another file where this facebookUser will be used, it's used as a promise, facebookUser.then .

facebookUser.then(function(user) {
    if (!user.loggedIn) {
       // reload the login route
       $location.path(facebookConfigSettings.loginPath || facebookConfigDefaults.loginPath);
    }
});