Question

我是Parse和Cloud Code的新手，但我已经设法编写了一些运行良好的AfterSave Cloud Code功能。但是，我在这个问题上遇到了很多麻烦，我无法弄清楚原因。请帮忙......

我有

两个PFObject类：Message和MessageThread
消息包含与MessageThread相关联的聊天消息
MessageThread包含一个成员数组（都是PFUsers）

插入Message后，我想查找相关MessageThread的所有成员并向他们推送通知

class MessageThread: PFObject {

    @NSManaged var members: [PFUser]
    @NSManaged var lastMessageDate: NSDate?
    @NSManaged var messageCount: NSNumber?

    override class func query() -> PFQuery? {
        let query = PFQuery(className: MessageThread.parseClassName())
        query.includeKey("members")
        return query
    }
    init(members: [PFUser], lastMessageDate: NSDate?, messageCount: NSNumber?) {
        super.init()

        self.members = members
        self.lastMessageDate = lastMessageDate
        self.messageCount = messageCount
    }

    override init() {
        super.init()
    }
}
extension MessageThread: PFSubclassing {
    class func parseClassName() -> String {
        return "MessageThread"
    }
    override class func initialize() {
        var onceToken: dispatch_once_t = 0
        dispatch_once(&onceToken) {
            self.registerSubclass()
        }
    }
}
class Message: PFObject {
    @NSManaged var messageThreadParent: MessageThread
    @NSManaged var from: PFUser
    @NSManaged var message: String
    @NSManaged var image: PFFile?

    override class func query() -> PFQuery? {
        let query = PFQuery(className: Message.parseClassName())
        query.includeKey("messageThreadParent")
        return query
    }
    init( messageThreadParent: MessageThread, from: PFUser, message: String, image: PFFile?) {
        super.init()

        self.messageThreadParent = messageThreadParent
        self.from = from
        self.message = message
        self.image = image
        }
    override init() {
        super.init()
    }
}
extension Message: PFSubclassing {
    class func parseClassName() -> String {
        return "Message"
    }
    override class func initialize() {
        var onceToken: dispatch_once_t = 0
        dispatch_once(&onceToken) {
            self.registerSubclass()
        }
    }
}

方法

从请求对象（消息）中获取其messageThreadParent
查找父MessageThread的成员，遍历它们等等。

问题

当我尝试检索MessageThread对象时，我尝试查询Id == threadParent.objectId。但是，此查询始终返回我当前所有8个MessageThread，而不是我需要的单个。

Parse.Cloud.afterSave(Parse.Object.extend("Message"), function(request) {

Parse.Cloud.useMasterKey();

var theMsg = request.object;
var threadParent;
var currUsername = request.user.get("username");
var threadUsers;
var usernameArray;

threadParent = request.object.get("messageThreadParent");

// promise 
queryM = new Parse.Query(Parse.Object.extend("MessageThread"));
queryM.include("members");
queryM.equalTo("id", threadParent.objectId);
queryM.find().then(function (threadParam) {

console.log(" threads: ");
console.log(threadParam.length); //this returns 8, which is the number of threads I have.  I would expect just 1, matching threadParent.objectId...
console.log("thread is: ");

//... additional code follows, which seems to work...

Answer 1

在整天解决了一个单独的问题后，我终于发现在Parse的Javascript SDK中，“id”和“objectId”之间存在差异。

更改此

 queryM.equalTo("objectId", threadParent.id); // works!

到

module Main where

import Control.Monad (msum)
import Control.Monad.Trans.Class
import Language.Haskell.Interpreter
import Happstack.Server (nullConf, simpleHTTP, toResponse, ok, path, dir)
import Happstack.Server.Internal.Monads
import Text.JSON.Generic
import qualified Database.Redis as R
import qualified Data.ByteString.Char8 as C

main :: IO ()
main = simpleHTTP nullConf $
        msum [dir "eval" $ path $ \s -> handleRequest s]

data Response = Response
        { success :: Bool
        , cacheHit :: Bool
        , result :: String
        , error :: String
        } deriving (Show, Data, Typeable)

myConnectionInfo :: R.ConnectInfo
myConnectionInfo = R.defaultConnectInfo

handleRequest :: String ->  ServerPartT IO String
handleRequest exp = lift $ evalExp exp

evalExp :: String -> IO String
evalExp exp = do
    cachedResult <- checkCache exp
    -- CODE FOR CHECKING CACHED RESULT IS NOT YET COMPLETE
    x <- runInterpreter $ setImports ["Prelude"] >> eval exp
    let (error, isSuccess, result) = case x of Left _ -> ("Parse error", False, "")
                                               Right b -> ("", True, b)
    let y = Response isSuccess False result error
    return $ encodeJSON y

checkCache :: String -> IO (Either R.Reply (Maybe C.ByteString))
checkCache exp = do
        conn <- R.connect myConnectionInfo
        R.runRedis conn $ R.get $ C.pack exp

解决了我的问题。

objectId上的PFQuery.find未在Parse JavaScript SDK（云代码）中返回唯一行

1 个答案: