Parse platform 将PFObject保存到云代码中的关系（Parse.com）

我想弄明白这件事已经有一段时间了，但我还是很困惑。我正在构建一个带有Parse.com后端的应用程序，我正在尝试实现这个功能，当用户a尝试向用户B发送游戏请求时，用户a和用户B都以PFRelation的方式获取游戏。我已经完成了在用户A（当前用户）发起请求后将游戏保存到其关系的部分：

NSString *challengePuzzleSize = [NSString stringWithFormat: @"%ld", (long)self.sizeSegmentedControl.selectedSegmentIndex + 5];
self.aNewMatch = [PFObject objectWithClassName:@"Messages"];
[self.aNewMatch setObject:file forKey:@"file"];
[self.aNewMatch setObject:fileType forKey:@"fileType"];
[self.aNewMatch setObject:self.opponent.objectId forKey:@"opponentIDs"];
[self.aNewMatch setObject:self.opponent.username forKey:@"opponentName"];
[self.aNewMatch setObject:[[PFUser currentUser] objectId] forKey:@"senderID"];
[self.aNewMatch setObject:[[PFUser currentUser] username] forKey:@"senderName"];
[self.aNewMatch setObject:self.opponent forKey:@"receiver"];
[self.aNewMatch setObject:challengePuzzleSize forKey:@"puzzleSize"];
[self.aNewMatch setObject:[PFUser currentUser] forKey:@"sender"];

[self.aNewMatch saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
    if (error) {
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"An error occurred." message:@"Please try sending your message again." delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
        [alertView show];
    }

    else {
        PFRelation *currentGamesSender = [self.currentUser relationForKey:@"currentGames"];
        NSLog(@"opponent: %@", self.opponent);

        [currentGamesSender addObject:self.aNewMatch];

        [self.currentUser saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
            if (error) {
                NSLog(@"Error %@ %@", error, [error userInfo]);
            }

            else {
                NSLog(@"WORKS");
            }
        }];

我知道我不能对用户B做同样的事情，因为他不是当前用户，出于安全原因，我会保存非当前用户。所以，我试图通过云代码来实现这一点，这是另一个人在我浏览解决方案时推荐的。我将此作为目标C中的要求：

[PFCloud callFunction:@"addCurrentGame" withParameters:@{@"userId": self.opponent.objectId, @"currentGameId": self.aNewMatch.objectId}];

但我不熟悉Javascript，我一直在试图找出如何将PFObject保存到用户B的关系，但它对我不起作用。这是代码：

Parse.Cloud.define("addCurrentGame", function(request, response) {
Parse.Cloud.useMasterKey();

var receiver = null;
var currentGame = null;

queryReceiverUser = new Parse.Query("User");
queryCurrentGame = new Parse.Query(“Messages”);
var receiverUserId = request.params.userId;
var currentGameId = request.params.currentGameId;

queryCurrentGame.get( currentGameId, {
    success: function(_currentGame) {
        currentGame = _currentGame;

    error: function(error) {
        console.log("Error retrieving user in query!");
    }
});

queryReceiverUser.get( receiverUserId, {
    success: function(_receiver) {
        receiver = _receiver;

        var currentGames = receiver.relation(“currentGames”);
        currentGames.add(currentGame);

        receiver.save(null, {
        success: function() { console.log("Saved receiver”); },
                                          error: function(err) { console.log("Error saving receiver, " + err.code); }
                                          });

        response.success("success");

    },

    error: function(error) {
        console.log("Error retrieving user in query!");
    }
});
});

---

我根本不知道如何用Javascript创建PFObject游戏并将其保存到用户B关系（我的代码不正确）。如果有人能帮我解决这个问题，那就太棒了

如果解决了问题，你可以将其标记为已解决；如果某个问题不起作用，你可以给我一些反馈。

Parse.Cloud.define('addCurrentGame', function(request, response) {
    Parse.Cloud.useMasterKey();
    var queryReceiverUser = new Parse.Query(Parse.User);
    var queryCurrentGame = new Parse.Query('Messages');
    var receiverUserId = request.params.userId;
    var currentGameId = request.params.currentGameId;
    return Parse.Promise.when([queryReceiverUser.get(receiverUserId), queryCurrentGame.get(currentGameId)])
        .then(function(user, game) {
            gameRelation = user.relation('currentGames');
            gameRelation.add(game);
            return user.save(null, {userMasterKey: true})
        }).then(function() {
            response.success('success');
        }, function() {
            response.error('error');
        });
});