解析云代码嵌套查询时未调用代码141成功/错误消息

Question

我一直收到一个代码141错误success/error未被调用。我正在运行另一个函数getCinemasInLocation，它返回类似于JSON的：{result:[result1，result2]}。我想对这个数组进行迭代，每次循环运行时都运行一个查询，并将所有结果传递给一个数组。也就是说，所有oterate的结果都将在一个数组中。我做得对吗？

//This function uses getCinemasInLocation to retrieve the movie objects that are showing in the cinemas
Parse.Cloud.define("getMovieIdsInCinemas", function(request, response) {
    var cinemasInLocaton = [];
    var theLocation = request.params.theLocation;
    cinemasInLocation = Parse.Cloud.run("getCinemasInLocation", {theLocation: theLocation});
    for (i = 0; i < cinemasInLocation.length; i++){
        var query = new Parse.Query("showing");
        var movieIds = [];
        query.equalTo("cinema", {
            __type: "Pointer",
            className: "Cinema",
            objectId: cinemasInLocation[i]
        });
        query.find({
            success: function(results) {
                for (var i = 0; i < results.length; i++) {
                    movieIds.push(results[i].get("movie"));
                }
            response.success(movieIds);
            },
            error: function() {
                response.error("movie lookup failed 2");
            }
        });
    }
});

这是不起作用的getCinemasInLocation

function getCinemasInLocation(theLocation) {
// some code
//var result = ["xiUXXYFhAl","Yanh9iDykk"];
//return result;
   var result = new Parse.Promise();
   var query = new Parse.Query("Cinema");
   query.equalTo("Location", theLocation);
    query.find({
        success: function(objects) {
            var cinemas = [];
            for (var i = 0; i < objects.length; i++) {
                var cinema = objects[i];
                cinemas.push(cinema.id);
            }
            result.resolve(cinemas);
        },
        error: function(error) {
            result.reject(error);
        }
    });
return result;
}

Answer 1

1. Parse.Cloud.run不返回数组。它返回一个Promise。因此，在同一文件中创建一个普通的javascript函数：getCinemasInLocation（）

2. 正如@Delhi所说，您只能调用response.success（）或response.error（）一次。所以，不要把它们放在一个循环中。

3. 并行使用Promises。因此，让我们使用Undercore的循环，而不是普通的FOR循环。您可以一次启动多个操作，然后使用Parse.Promise.when创建一个新的Promise，当它的所有输入Promise都被解析时，该Promise就会被解析。您可以在文档中阅读更多相关信息：https://www.parse.com/docs/js_guide#promises-平行

var _ = require('underscore');

function getCinemasInLocation(theLocation) {
    // some code
    var result = [id1, id2];
    return result;
}
// This function returns the array of movieIds of a cinema
function getMovieIdsInCinema(cinemaId) {
    var result = new Parse.Promise();
    var query = new Parse.Query("showing");
    query.equalTo("cinema", {
        __type: "Pointer",
        className: "Cinema",
        objectId: cinemaId
    });
    query.find({
        success: function(objects) {
            var movieIds = [];
            for (var i = 0; i < objects.length; i++) {
                var movie = objects[i].get("movie");
                movieIds.push(movie.id);
            }
            result.resolve(movieIds);
        },
        error: function(error) {
            result.reject(error);
        }
    });
    return result;
}
Parse.Cloud.define("getMovieIdsInCinemas", function(request, response) {
    var cinemasInLocation = [];
    var theLocation = request.params.theLocation;
    cinemasInLocation = getCinemasInLocation(theLocation);
    var promises = [];
    _.each(cinemasInLocation, function(cinemaId) {
        promises.push(getMovieIdsInCinema(cinemaId));
    });
    Parse.Promise.when(promises).then(
        function() {
            var result = [];
            _.each(arguments, function(object) {
                result.push(object); // each object is an array of movieIds
            });
            response.success(result); // return array of arrays
        },
        function(error) {
            response.error(error);
        }
    );
});