Angular: service vs provider vs factory?

http://angularjs.org/

by Zineb ERRAHMOUNI

HTML

<script src="http://code.angularjs.org/angular-1.0.0.js"></script>
<div ng-controller="MyCtrl">
    {{hellos}}
</div>

<pre>
Services

Syntax: module.service( 'serviceName', function ); Result: When declaring serviceName as an injectable argument you will be provided with an instance of the function. In other words new FunctionYouPassedToService().

Factories

Syntax: module.factory( 'factoryName', function ); Result: When declaring factoryName as an injectable argument you will be provided with the value that is returned by invoking the function reference passed to module.factory.

Providers

Syntax: module.provider( 'providerName', function ); Result: When declaring providerName as an injectable argument you will be provided with new ProviderFunction().$get(). The constructor function is instantiated before the $get method is called - ProviderFunction is the function reference passed to module.provider.

Providers have the advantage that they can be configured during the module configuration phase.
</pre>

JavaScript

var myApp = angular.module('myApp', []);

//service style, probably the simplest one
myApp.service('helloWorldFromService', function() {
    this.sayHello = function() {
        return "Hello, World!"
    };
});

//factory style, more involved but more sophisticated
myApp.factory('helloWorldFromFactory', function() {
    return {
        sayHello: function() {
            return "Hello, World!"
        }
    };
});
    
//provider style, full blown, configurable version     
myApp.provider('helloWorld', function() {

    this.name = 'Default';

    this.$get = function() {
        var name = this.name;
        return {
            sayHello: function() {
                return "Hello, " + name + "!"
            }
        }
    };

    this.setName = function(name) {
        this.name = name;
    };
});

//hey, we can configure a provider!            
myApp.config(function(helloWorldProvider){
    helloWorldProvider.setName('World');
});
        

function MyCtrl($scope, helloWorld, helloWorldFromFactory, helloWorldFromService) {
    
    $scope.hellos = [
        helloWorld.sayHello(),
        helloWorldFromFactory.sayHello(),
        helloWorldFromService.sayHello()];
}