[AngularJS][Ionic] 让控制器等待使用另一个 $http 服务的服务

Question

问题是控制器不等待使用另一个 $http 服务的服务，我没有得到任何数据。

services.js：

angular.module('starter.services', [])
    .factory('Likes', function ($http) {
        var likes;
        $http.get("http://localhost:8100/js/offers.json")
                .success(function (results) {
                    likes = results.offers;
                    console.log("ok!");
                })
                .error(function (results) {
                    console.log("error");
                });
        return {
            all: function () {
                return likes;
            },
            get: function (likeId) {
                for (var i = 0; i < likes.length; i++) {
                    if (likes[i].id === parseInt(likeId)) {
                        return likes[i];
                    }
                }
                return null;
            }
        };

    })

controllers.js（部分）：

.controller('OneCtrl', function($scope, $stateParams, Likes) {
  $scope.offer = Likes.get($stateParams.likedId);
})

.controller('LikedCtrl', function($scope, $stateParams, $http, Likes) {
  $scope.liked = Likes.all();
})

我已经阅读了有关 Promise、async()、回调和 $q 的文章和主题，但我不知道如何将这些东西集成到我的代码中，尽管尝试了很多次。

Answer 1

从您的服务中返回承诺：

angular.module('starter.services', [])
.factory('Likes', function ($http) {
    // likes is a promise of array of likes
    var likes = $http.get("http://localhost:8100/js/offers.json")
            // then allows transforming the promise of http response into a promise of something else
            .then(function(response) {
                // transforms the http response into an array of likes
                return response.data.offers;
            });
    return {
        // all returns a promise of array of likes
        all: function () {
            return likes;
        },
        // get returns a promise of like
        get: function (likeId) {
            // then allows transforming a promise of array of likes into a promise of something else
            return likes.then(function(likes) {
                // transform the array of likes into a single like
                for (var i = 0; i < likes.length; i++) {
                    if (likes[i].id === parseInt(likeId)) {
                        return likes[i];
                    }
                }
                return null;
            }
        }
    };
});

在控制器中

.controller('OneCtrl', function($scope, $stateParams, Likes) {
    Likes.get($stateParams.likedId).then(function(like) {
        $scope.offer = like;
    });
})