javascript - AngularJS 类型错误 : "track" is not a function

Question

我正在尝试使用我的 Controller 方法中的参数调用服务，但我收到一条错误消息，指出它不是一个函数。这是我的代码:

(function (){

angular.module('app.uploadedReleases')
        .controller('UploadedReleasesController', UploadedReleasesController)
        .controller('ModalController', ModalController);


UploadedReleasesController.$inject = ['$log', '$scope', '$modal', 'ReleaseService', 'TrackService'];
function UploadedReleasesController ($log, $scope, $modal, releaseService, trackService){

        vm.selectTrack = selectTrack;

       function selectTrack(album, track, index){

        trackService.currentTrack(album.slug, track.fileName).then(function(responseValue){
            vm.temp = responseValue;
        });
        vm.formTrack = vm.selected.track;
    }
}

这是我的名为 trackService 的服务:

angular.module('app.services')
        .service('TrackService', TrackService);

TrackService.$inject = ['$http', '$q'];

function TrackService($http, $q){
    var trackService = {};

    var releasesUrl = 'http://localhost:8080/api/releases';
    trackService.currentTrack = currentTrack;

        function currentTrack(releaseSlug, trackSlug){
        var trackUrl = releasesUrl + '/'+ releaseSlug + '/' + trackSlug + '/track';
        var deferred = $q.defer();

        $http.get(trackUrl).then(function(trackResponse){
            return deferred.resolve(trackResponse);
        }, function(error){
            return deferred.reject({msg: 'Error while getting the current track details'})
        });
      return deferred.promise;
    }
}

知道为什么我的 Controller 会出现错误:TypeError: trackService.currentTrack is not a function

Answer 1

@Pankaj Parkar 的回答是正确的，因为您应该从 currentTrack 返回一个 promise ，以便在您的 Controller 中链接 then。

但是，为了回答有关 TypeError 的问题，您在 TrackService 中混合了工厂和服务语法。

要使其成为工厂，返回公开函数的映射:

function TrackService($http, $q){
    var trackService = {};
    trackService.currentTrack = currentTrack;

    function currentTrack(releaseSlug, trackSlug){
        //...
    }

    return trackService;
}

并用.factory('TrackService', TrackService);声明。

要使其成为服务，请将公开的函数添加到this:

function TrackService($http, $q){
    this.currentTrack = currentTrack;

    function currentTrack(releaseSlug, trackSlug){
        //...
    }
}

并使用 .service('TrackService', TrackService); 声明。