Angular $q 返回承诺多个 $http 调用

问题描述

我正在处理 $http 调用，该调用会遍历多个 api 中的每一个并返回一个对象中的所有数据.我通常会在调用 $http 时准备好解决的承诺.类似这样:

I'm working on an $http call that loops over each of multiple api's and returns all of the data in one object. I usually have the promise ready to resolve when the $http call has been made. Similar to this:

function getAllData(api) {
    return $http({
        method: 'GET',
        url: '/api/' + api
    })
    .then(sendResponseData)
    .catch (sendGetVolunteerError);
}

当前函数我循环遍历每个 api 并将 api 中的每个对象推送到一个数组中，然后将其推送到一个整体数组中.我有这个功能，返回一个多维数组，需要展平.

The current function I have loops over each api and pushes each object in the api into an array and then pushes it into an overall array. I had this functioning, returning an multi-dimensional array, which needed to be flattened out.

我想在承诺中返回它，但返回 undefined.这是我到目前为止所拥有的?有没有更好的方法来解决这个问题?

I'd like to return this in a promise, but am returning undefined. Here is what I have so far? Is there a better way to approach this?

数据服务:

function getSearchData() {
    return {
        loadDataFromUrls: function () {
            var apiList = ["abo", "ser", "vol", "con", "giv", "blo", "par"];
            var deferred = $q.defer();
            var log = [];
            angular.forEach(apiList, function (item, key) {
                var logNew = [];
                $http({
                    method: 'GET',
                    url: '/api/' + item
                }).then(function (response) {
                    angular.forEach(response.data, function (item, key) {
                        this.push(item);
                    }, logNew);
                    return logNew;
                });
                this.push(logNew);
            }, log);
            $q.all(log).then(

            function (results) {
                deferred.resolve(
                JSON.stringify(results))
            },

            function (errors) {
                deferred.reject(errors);
            },

            function (updates) {
                deferred.update(updates);
            });
            return deferred.promise;
        }
    };
};

控制器:

function getSearchData(){
  return dataService.getSearchData.loadDataFromUrls;
}

$scope.searchData = getSearchData();

推荐答案

$q.all 和 map 函数是你需要的:

$q.all and a map function are what you need here:

function getSearchData() {
    return {
        // returns a promise for an object like:
        // { abo: resultFromAbo, ser: resultFromSer, ... }
        loadDataFromUrls: function () {
            var apiList = ["abo", "ser", "vol", "con", "giv", "blo", "par"];

            return $q.all(apiList.map(function (item) {
                return $http({
                    method: 'GET',
                    url: '/api/' + item
                });
            }))
            .then(function (results) {
                var resultObj = {};
                results.forEach(function (val, i) {
                    resultObj[apiList[i]] = val.data;
                });
                return resultObj;
            });
        }
    };
}

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