Promise API

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

app.service('Service', function($q, $timeout) {

    function methodWithPromise() {
        var deferred = $q.defer();

        setTimeout(function() {
            // called multiple times
            deferred.notify("10%");
            deferred.notify("30%");
            deferred.notify("70%");
            deferred.notify("100%");

            // deferred.reject(new Error());
            deferred.resolve('YAY');

        });

        return deferred.promise;
    }

    return {
        methodWithPromise: methodWithPromise
    };
})

app.controller('MainCtrl', function($scope, Service) {
    var count = 0;

    $scope.$watch(function() {
        console.log(++count);
    });

    console.clear();

    function showResult(result) {
        console.info('success:', result);
    }

    function showError(error) {
        console.error('error:', error);
    }

    function finalize() {
        console.log('finally!');
    }

    function showProgress(progressValue) {
        console.info('progress:', progressValue);
    }

    Service.methodWithPromise()
        .then(showResult, null, showProgress)
        .catch (showError)
        .finally(finalize);

});

<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.2.x" src="https://code.angularjs.org/1.2.21/angular.js" data-semver="1.2.21"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl"></body>

</html>

/* Put your css in here */