Question

我正在尝试在解析时运行一些云函数，但originalFavorited.first没有运行。

var _ = require('underscore');
Parse.Cloud.define("userFeed", function (request, response) {
    if (request.user == undefined) {
        response.error("User must be logged in!");
    }

    var friendsQuery = new Parse.Query("Friend");
    friendsQuery.equalTo("fromUser", request.user);

    var badPhotosQuery = new Parse.Query("Photo");
    badPhotosQuery.greaterThanOrEqualTo("flagCount", 3);

    var userFlaggedQuery = new Parse.Query("Photo");
    userFlaggedQuery.containedIn("flagCount", request.user.flaggedItems);

    var allBadPhotosQuery = new Parse.Query.or(badPhotosQuery, userFlaggedQuery);

    var activitiesQuery = new Parse.Query("Activity");
    activitiesQuery.skip(request.params.startRecord);
    activitiesQuery.limit(request.params.numberRecords);
    activitiesQuery.equalTo("type", "favorite");
    activitiesQuery.matchesKeyInQuery("fromUser", "toUser", friendsQuery);
    activitiesQuery.descending("createdAt");
    activitiesQuery.include("photo")
    activitiesQuery.include("fromUser");
    activitiesQuery.notEqualTo("fromUser", request.user);
    activitiesQuery.doesNotMatchQuery("photo", allBadPhotosQuery);


    var parsedResults = [];
    activitiesQuery.find().then(function (results) {
        return results;
    }).then(function (results) {

        var promise = Parse.Promise.as();

        _.each(results, function (activity) {
            promise = promise.then(function () {
                console.log("Parsing results for " + activity);
                var originalFavorited = new Parse.Query("Activity");
                originalFavorited.ascending("createdAt");
                console.log(activity.get("photo"));
                originalFavorited.equalTo("photo", activity.get("photo"));
                originalFavorited.include("photo");
                originalFavorited.include("fromUser");
                originalFavorited.equalTo("type", "favorite");

                originalFavorited.first(function (origResult) {

                    console.log("Found original");
                    parsedResults.push(origResult);
                    return parsedResults;
                });
            });
        });
        return promise;
    }).then(function () {
        var filteredResults = _.uniq(parsedResults, false);
        response.success(filteredResults);
    });

我的输出console.log (activity.get("photo"));正在输出对象。 photo是指向Photo班级的指针。

我是否正确地执行了承诺，以便同步运行代码？

Answer 1

试试这个：

var parsedResults = [];
activitiesQuery.find().then(function (results) {

    /// ---- REMOVED HERE ----
    // return results;
    //    }).then(function (results) {

    var promise = Parse.Promise.as();

    _.each(results, function (activity) {
        promise = promise.then(function () {
            console.log("Parsing results for " + activity);
            var originalFavorited = new Parse.Query("Activity");
            originalFavorited.ascending("createdAt");
            console.log(activity.get("photo"));
            originalFavorited.equalTo("photo", activity.get("photo"));
            // the two line belows can be ignored since you have the same value in activity.get("photo") and activity.get("fromUser"), included previously
            originalFavorited.include("photo");
            originalFavorited.include("fromUser");
            originalFavorited.equalTo("type", "favorite");

            /// ---- ADDED LINE BELOW ----
            originalFavorited.limit(1);
            originalFavorited.find(function (subResults) {

                console.log("Found original");

                /// ADDED CHECK HERE 
                if (subResults.length > 0){
                    parsedResults.push(subResults[0]);
                }

                /// ---- CHANGED HERE ----
                var subPromise = Parse.Promise.as();
                subPromise.resolve(parsedResults);
                return subPromise ; // returning a promise to promise series

            /// ---- ADDED ERROR HANDLING HERE ----
            },function(error){

                console.log("Unable to retrieve first element in originalFavorited query. Cause: " + error.message);
                var errPromise = Parse.Promise.as();
                errPromise.reject(error);
                return errPromise; // return failed promise to promise series just for continue the operation series up to the end
            });
        });
    });

    return promise;

},function(error){  /// ---- ADDED ERROR HANDLING HERE ----

    console.log("Unable to perform find on activitiesQuery : " + error.message);
    response.error(error.message);

}).then(function () {
    var filteredResults = _.uniq(parsedResults, false);
    response.success(filteredResults);
});

注意：不要忘记自定义函数的解析限制执行，因此请正确选择要为每个自定义函数调用执行的查询量

解析云代码相互依赖的多个查询

1 个答案: