Firebase / iOS：runTransactions有时不起作用

时间：2016-06-12 13:16:48

标签： ios swift firebase firebase-realtime-database

我正在开发一个聊天应用，用户应该收到有关其联系人新消息的通知。此通知消息还应包括未读消息的数量。由于发件人和收件人都可以更新此信息，因此首选runTransaction。不幸的是，有时它不起作用。感觉＆＃34;卡住＆＃34;然后再开始工作一段时间。 privateChats节点（见下文）始终使用最新消息进行更新，但不会更新openChatMessages节点。

如果在短时间内发送了很多邮件，是否会发生这种情况，即同一runTransactions ref执行频繁privateChats $userId $chatId $messageId text timestamp senderId senderEmail senderName // this node contains information about open chats // like last message and counter for unread messages openChatMessages $userId $chatId text timestamp senderId senderEmail senderName counter ？

我的数据结构：

class ChatViewController: JSQMessagesViewController {

    var user: FIRUser!
    var ref: FIRDatabaseReference!
    var chatRef: FIRDatabaseReference!
    var senderOpenChatRef: FIRDatabaseReference!
    var receiverOpenChatRef: FIRDatabaseReference!

    // the following variables will be set before ChatViewController appears

    var chatId: String?
    var receivId: String?
    var receiverEmail: String?
    var receiverName: String?

    override func viewDidLoad() {
        super.viewDidLoad()
        self.user = FIRAuth.auth()?.currentUser!
        self.ref = FIRDatabase.database().reference()
        self.chatRef = self.ref.child("privateChats").child(self.user.uid).child(self.chatId!)
        self.senderOpenChatRef = self.ref.child("openChatMessages").child(self.user.uid).child(self.chatId!)
        self.receiverOpenChatRef = self.ref.child("openChatMessages").child(self.receiverId!).child(self.chatId!)
    }

    func sendMessage(text: String) {
        var messageObject = [String: AnyObject]()
        messageObject["text"] = text
        messageObject["timestamp"] = FIRServerValue.timestamp()
        messageObject["senderEmail"] = self.user.email
        messageObject["senderName"] = self.user.displayName
        messageObject["senderId"] = self.user.uid

        let messageId = self.ref.child("privateChats").child(self.user.uid).child(self.chatId!).childByAutoId().key

        let childUpdates = [
            "/privateChats/\(self.user.uid)/\(self.chatId!)/\(messageId)": messageObject,
            "/privateChats/\(self.receiverId!)/\(self.chatId!)/\(messageId)": messageObject
        ]

        self.ref.updateChildValues(childUpdates, withCompletionBlock: { (error, ref) -> Void in
            if error != nil {
                print("childUpdates error:\(error)")
                return
            }

            JSQSystemSoundPlayer.jsq_playMessageSentSound()
            self.finishSendingMessage()
            self.updateOpenChats(text)
        })
    }


    func updateOpenChats(text: String) {

        // update the receivers openChatObject with increasing the counter
        self.receiverOpenChatRef.runTransactionBlock({ (currentData: FIRMutableData) -> FIRTransactionResult in

            var openChatObject = [String: AnyObject]()

            // update openChatObject with the latest information from currentData
            if currentData.hasChildren() {
                 openChatObject = currentData.value as! [String: AnyObject]
            }

            openChatObject["text"] = text
            openChatObject["timestamp"] = FIRServerValue.timestamp()
            openChatObject["senderEmail"] = self.user.email
            openChatObject["senderName"] = self.user.displayName
            openChatObject["senderId"] = self.user.uid

            var counter = openChatObject["counter"] as? Int
            if counter == nil {
                counter = 1
            } else {
                counter = counter! + 1
            }
            openChatObject["counter"] = counter

            currentData.value = openChatObject
            return FIRTransactionResult.successWithValue(currentData)
            }) { (error, committed, snapshot) in
                if let error = error {
                    print("updateOpenChats: \(error.localizedDescription)")
                }
        }

        // update your (the sender's) openChatObject with setting the counter to zero
        self.senderOpenChatRef.runTransactionBlock({ (currentData: FIRMutableData) -> FIRTransactionResult in

            var openChatObject = [String: AnyObject]()

            // update openChatObject with the latest information from currentData
            if currentData.hasChildren() {
                 openChatObject = currentData.value as! [String: AnyObject]
            }

            openChatObject["text"] = text
            openChatObject["timestamp"] = FIRServerValue.timestamp()
            openChatObject["senderEmail"] = self.receiverEmail
            openChatObject["senderName"] = self.receiverName
            openChatObject["senderId"] = self.receiverId
            openChatObject["counter"] = 0

            currentData.value = openChatObject
            return FIRTransactionResult.successWithValue(currentData)
            }) { (error, committed, snapshot) in
                if let error = error {
                    print(error.localizedDescription)
                }
        }
    }
}

我的代码：

text

修改

与我的第一个答案的期望相反，错误仍然存​​在。我认为它与连接有关？例如。当没有良好的连接时，有时需要更长的时间来运行交易？但有时当我坐在路由器旁边时也会发生这种情况。其他节点被写入，但不会写入事务。在这些情况下重新启动应用程序后，它再次开始工作。所以我觉得引擎盖下有什么问题。

我非常感谢这个问题的解决方案。接收器有时无法收到有关新消息的通知的聊天应用程序是不行的。

我也熟悉解决方法：当你想增加一个计数器时，实际上是否需要交易？我可以使用senderId更新timestamp，setValue或func sendMessage(text: String?, video: NSURL?, image: UIImage?) { var messageObject = [String: AnyObject]() messageObject["text"] = text messageObject["timestamp"] = FIRServerValue.timestamp() messageObject["senderEmail"] = self.user.email messageObject["senderName"] = self.user.displayName messageObject["senderId"] = self.user.uid func completeSending() { let messagesRef = self.ref.child("messages").child(self.chatId!).childByAutoId() messagesRef.setValue(messageObject) JSQSystemSoundPlayer.jsq_playMessageSentSound() if let _ = image { self.updateOpenChats(" Photo") } else if let text = text { self.updateOpenChats(text) } self.finishSendingMessageAnimated(true) } if let image = image { // if an image is being sent let data: NSData = UIImageJPEGRepresentation(image, 0.37)! let fileName = "image_\(NSDate().timeIntervalSince1970).jpg" let chatImagesRef = storageRef.child("chatImages/\(self.chatId!)/\(fileName)") let uploadTask = chatImagesRef.putData(data, metadata: nil) { metadata, error in if (error != nil) { print(error) return } } uploadTask.observeStatus(.Failure) { snapshot in ProgressHUD.showError("Uploading image failed.") } uploadTask.observeStatus(.Success) { snapshot in let imageUrl = snapshot.reference messageObject["imageUrl"] = String(imageUrl) completeSending() } } else { // if it's just a text message completeSending() } } func updateOpenChats(text: String) { self.receiverChatRef.runTransactionBlock({ (currentData: FIRMutableData) -> FIRTransactionResult in var openChatObject = [String: AnyObject]() if currentData.hasChildren() { openChatObject = currentData.value as! [String: AnyObject] } openChatObject["text"] = text openChatObject["timestamp"] = FIRServerValue.timestamp() openChatObject["senderEmail"] = self.user.email openChatObject["senderName"] = self.user.displayName openChatObject["senderId"] = self.user.uid openChatObject["pushId"] = Database.pushId var counter = openChatObject["counter"] as? Int if counter == nil { counter = 1 } else { counter = counter! + 1 } openChatObject["counter"] = counter // Set value and report transaction success currentData.value = openChatObject return FIRTransactionResult.successWithValue(currentData) }) { (error, committed, snapshot) in if let error = error { print("updateOpenChats: \(error.localizedDescription)") } } self.senderChatRef.runTransactionBlock({ (currentData: FIRMutableData) -> FIRTransactionResult in var openChatObject = [String: AnyObject]() if currentData.hasChildren() { openChatObject = currentData.value as! [String: AnyObject] } openChatObject["text"] = text openChatObject["timestamp"] = FIRServerValue.timestamp() openChatObject["senderEmail"] = self.receiver.email openChatObject["senderName"] = self.receiver.name openChatObject["senderId"] = self.receiver.uid openChatObject["counter"] = 0 // Set value and report transaction success currentData.value = openChatObject return FIRTransactionResult.successWithValue(currentData) }) { (error, committed, snapshot) in if let error = error { print(error.localizedDescription) } } } 等其他数据，但当两个用户都尝试设置子节点的值时，这会导致数据损坏同时，不是吗？

这是我的最新代码：

MaintainFormDto

1 个答案:

答案 0 :(得分：4)

好吧，显然Firebase SDK中存在一个错误。即使更新成功，有时也无法执行completionBlock的回调。我删除了 self.ref.updateChildValues(childUpdates) JSQSystemSoundPlayer.jsq_playMessageSentSound() self.finishSendingMessage() self.updateOpenChats(text) ，现在它完美无缺。

<?php

function DecryptId($id) {
    $first_digit = substr($id, 0,1);

    if ( $first_digit == 0 ) {
        return 'yes';
    } else {
        return 'no';
    }
}

$id = '014';
echo DecryptId($id);
?>

修改 看到更新的问题，问题仍然存在。

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