AngularJS TypeError: "track" is not a function

Question

我正在尝试使用我的控制器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;
    }
}

知道为什么我的控制器会出现错误：TypeError: trackService.currentTrack is not a function

Answer 1

我要说的第一件事是，您正在创建一个服务，那么您应该将方法绑定到 this 上下文，而不是创建对象。

var trackService = {};

将更改为

var trackService = this;

但是 return从服务中获取自定义对象也没有错。所以在目前的情况下你错过了 returned 它。在您的服务代码末尾添加

return trackService

仍然对服务和工厂的工作方式感到困惑，我建议阅读 this answer

您应该 return 来自您以自定义方式创建的 trackService.currentTrack 方法的承诺。

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; //returned promise
}

相反，你应该做你的自定义承诺，它被认为是反模式来实现你有承诺的地方 return 通过 $http.get 方法，你应该利用它。

重构版本

trackService.currentTrack = currentTrack;
    function currentTrack(releaseSlug, trackSlug){
    var trackUrl = releasesUrl + '/'+ releaseSlug + '/' + trackSlug + '/track';
    return $http.get(trackUrl).then(function(trackResponse){
        return trackResponse;
    }, function(error){
        return {msg: 'Error while getting the current track details'};
    });
}

Answer 2

@Pankaj Parkar 的回答是正确的，因为你应该 returning 来自 currentTrack 的承诺，以便在你的控制器中链接 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，return 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，请将公开的功能添加到 this:

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

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

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

AngularJS TypeError: "track" is not a function

AngularJS TypeError: "track" is not a function

javascript

angularjs

angularjs-service

angularjs-http