TypeScript+ Angular DataService based on observer pattern

DataService.ts

module CommonServices {
    export class DataService<T> {
        public data: T;
        private observerCallbacks = [];     // Observer pattern implementation

        public registerCallback = (callback) => {
            this.observerCallbacks.push(callback);
        };
        public setData = (instance: T) => {
            this.data = instance;
            angular.forEach(this.observerCallbacks,(callback?: Function) => callback());
        };
        public getData = (): T => {
            return this.data;
        }
    }
}

IterationDataService.ts

module Projects {
    "use strict";
    
    export class IterationDataService extends  CommonServices.DataService<Iteration> {
        public static Factory() {            
            return new IterationDataService();
        }
    }
}

//registration as data service
angular.module("projects", [])
.factory("IterationDataService", Projects.IterationDataService.Factory)

IterationsCtrl.ts

module Projects {
    "use strict";

    export class IterationDetailsCtrl {
        public static $inject = ["$scope", "$http", "$state", "IterationDataService"];

        constructor(public $scope: ng.IScope
            , public $http: ng.IHttpService
            , public $state: ng.ui.IStateService
            , public IterationDataService: IterationDataService
            ) {
            super($scope);
            var me = this;
            
            //setting data
            $http.get(me.getUrl())
                .success((data: Iteration) => {
                me.iteration = data;
                me.IterationDataService.setData(me.iteration);
            });

            //getting data
            this.IterationDataService.registerCallback(() => {
                me.iteration = this.IterationDataService.getData();
            });