Angular 承诺使用多个 http 请求

Question

我之前已经阅读了一些关于 Angular Promise 的论坛帖子，但无法让它在我的实例中发挥作用。我在后端使用 nodejs /locomotive，前端使用 Angular。

我在控制器中有以下代码，基本上我想使用 slides.path 的路径，我将如何使用 Promise 来执行此操作？任何帮助将不胜感激。

function ProductCtrl($scope, $http, $q) {

    $scope.events = [];
    $scope.times = [];

    var html = [];
    var chapters = [];
    var path;

    //var paPromise = $q.defer();

    $http({
        url: '/show',
        method: 'GET',
        params: { eventid:$scope.$routeParams.eventid}

    }).success(function(response, code) {

        $scope.events = response;

        angular.forEach($scope.events.slides, function(slide) {

            $http({
                url: '/upload',
                method: 'GET',
                params: {uploadid: slide.upload.toString()}

            }).success(function(response, code) {
                return "http://www.example.com/"+response.path;

            },path);

            slide.path = path;

            chapters.push(slide);

        });

    });
}

Answer 1

您可以使用 $q.all 来完成这个多重承诺问题。像这样：

function ProductCtrl($scope, $http, $q) {

$scope.events = [];
$scope.times = [];

var html = [];

var path;

function fetchChapter() {
    var chapters = [];

    var httpPromise = $http({
        url: '/show',
        method: 'GET',
        params: {
            eventid: $scope.$routeParams.eventid
        }
    });

    //Return the value http Promise
    return httpPromise.then(function (response) {
        $scope.events = response;
        var promises = [];
        angular.forEach($scope.events.slides, function (slide) {

            var inPromise = $http({
                url: '/upload',
                method: 'GET',
                params: {
                    uploadid: slide.upload.toString()
                }
            }).then(function (response, code) {
                //each promise makes sure, that he pushes the data into the chapters
                slide.path = "http://www.example.com/" + response.path;
                chapters.push(slide);
            });
            //Push the promise into an array
            promises.push(inPromise);
        });
        //return the promise from the $q.all, that makes sure, that all pushed promises are ready and return the chapters.
        return $q.all(promises).then(function () {
            return chapters;
        });
    });
}

fetchChapter().then(function(chapters){
   //populate here 
});

}

httpPromise 将从 $q.all 返回承诺。

编辑：那么如何获取数据 包装一个函数，我用fetchChapter 做了一个函数并将一个函数传递给then 会有你需要的值作为参数。