angularServices.js

//from most to least verbose, but it is all the same in the end. 

(function() {

    var module = angular.module("myApp.myModel", []);
    
    var MyModel = function MyModel() {
        this.asyncService = null;

        this.someApi = function() {
            return this.asyncService.getStuff(); //promise?
        }

    }

    var myModelProvider = Class.extend({
        model: new MyModel();
        $get: ['asyncService', function (asyncService) {
            model.asyncService = asyncService; //dependency injection
            return model; //resolved for the lifetime of app
        }]
    });

    modules.provider('myModel', myModelProvider);
}())

// or

(function() {

    var module = angular.module("myApp.myModel", []);
    
    var MyModel = function MyModel(asyncService) {
        this.asyncService = null;

        this.someApi = function() {
            return this.asyncService.getStuff(); //promise?
        }

    }

    module.factory('myModel', ['asyncService', function (asyncService) {
        //could do some stuff here
        return new MyModel(asyncService); 
    }]);

}())

// or

(function() {

    var module = angular.module("myApp.myModel", []);
    
    var MyModel = function MyModel(asyncService) {
        this.asyncService = null;

        this.someApi = function() {
            return this.asyncService.getStuff(); //promise?
        }

    }

    module.service('myModel', ['$asyncService', MyModel]); //most simple option
}())

$asyncService is another instance (of a Class, object, function) that was

1. registered with Angular (via .service() or .factory(), and then later...
2. instantiated by the Angular engine during the app bootstrapping processes

// register AsyncService to create instance of $asyncService
angular.module( "myApp.myModel", [ ])
          .service( "$asyncService", AsyncService)
          .service('myModel', MyModel);

This instance $asyncService is then injected as an parameter to the function MyModel( ) invocation; which creates an instance of myModel.

See how Angular allows you to create beans/services, define dependencies, and auto-injects those as needed?