追随者计数器不更新Firebase中的节点 [英] Follower counter not updating node in firebase

问题描述

我一直在试图在我的应用程序上实现跟随功能。实际上，当用户点击关注按钮时，我们运行一个 runTransactionBlock 来更新我们存储在Firebase数据库中的用户和他们关注的帐户的整数值。 问题是我能够更新用户的计数器（比如下面的例子中的John），但是我无法更新我正在关注的用户的计数器（比如下面的奥利维亚例子）。

目前Firebase节点看起来像这样：

$ p $ user_profiles {
UID1：{
名称：john
以下内容：1 //代码将更新我的帐户
追随者：0
}，
UID2：{
名称：olivia
以下：0
追随者：0 //代码不会更新人数，我正在尝试追踪


我引用了下面的内容，但是我仍然面临着这个问题。如果任何人都可以请扫一眼，指向正确的方向，这将不胜感激。

https ：//www.firebase.com/docs/ios/guide/saving-data.html

  var guestUIDToPass = String（）
 var loggedInUser = AnyObject（）
 $ b @IBAction func didTapFollow（sender：AnyObject）{
 following（）
 
 
 
 
 func（）{
 
 self.loggedInUser = FIRAuth.auth（）？。currentUser 
 
 
 //为用户更新计数，完美工作
 $ b $ self.databaseRef.child（user_profiles）。child（self.loggedInUser.uid）.child（following）。 runTransactionBlock（{
（currentData：FIRMutab leData！）in 
 var value = currentData.value as？ Int 
 if（value == nil）{
 value = 0 
} 
 currentData.value = value！ + 1 
返回FIRTransactionResult.successWithValue（currentData）
}）
 
 //更新次数为用户所关注，不更新firebase 
 
 （$ {$ b $（currentData：FIRMutableData！）in 
 var（user_profiles value = currentData.value as？Int 
 if（value == nil）{
 value = 0 
} 
 currentData.value = value！+ 1 
返回FIRTransactionResult .successWithValue（currentData）
 
}）
} 
  

解决方案

试试：

$ b $

  let prntRef = FIRDatabase.database（）。 （user_profiles）。child（whoifollowedUID）.child（following）
 
 prntRef.runTransactionBlock（{（following） - > 
中的FIRTransactionResult如果let followNum = followin g.value as？Int {
 
 following.value = followNum + 1 
 return FIRTransactionResult.successWithValue（following）
} else {
 
 return FIRTransactionResult .successWithValue（以下）
 
 $ b}，和CompletionBlock：{（错误，完成，快照）
 
 print（error？.localizedDescription）
打印（完成）
打印（快照）
 if！完成{
 
 print（值无法更新）
} else {
 //已更新
} 
}）
  

I have been trying to implement a "follow" function on my app. Essentially when a user hits the "follow" button, we run a runTransactionBlock to update integer values we are storing on Firebase database for the user and the account they are following. The issue is that I am able to update the counter for the user (say John in example below) , but I am not able to update the counter for the user I am following (say olivia in example below).

Currently the Firebase nodes look as such:

user_profiles{
      UID1:{
           name: john
           following: 1 //code will update for my account
           followers: 0
      },
      UID2:{
           name: olivia
           following: 0
           followers: 0 //code will not update count for person i am trying to follow

I have referenced the following, however I am still facing issues with getting this to work. If anyone can please glance through and point me in the right direction, it would be greatly appreciated.

https://www.firebase.com/docs/ios/guide/saving-data.html

Firebase database help - Swift

Upvote/Downvote system within Swift via Firebase

var guestUIDToPass = String()
var loggedInUser = AnyObject()

@IBAction func didTapFollow(sender: AnyObject) {
 following() 
}



func following() {

        self.loggedInUser = FIRAuth.auth()?.currentUser


//updating count for user, works perfectly        

self.databaseRef.child("user_profiles").child(self.loggedInUser.uid).child("following").runTransactionBlock({
            (currentData:FIRMutableData!) in
            var value = currentData.value as? Int
            if (value == nil) {
                value = 0
            }
            currentData.value = value! + 1
            return FIRTransactionResult.successWithValue(currentData)
        })

//updating count for person user is following, doesn't update firebase

        self.databaseRef.child("user_profiles").child("\(self.guestUIDToPass)").child("followers").runTransactionBlock({
            (currentData:FIRMutableData!) in
            var value = currentData.value as? Int
            if (value == nil) {
                value = 0
            }
            currentData.value = value! + 1
            return FIRTransactionResult.successWithValue(currentData)

        })
    }

解决方案

Try:-

let prntRef = FIRDatabase.database().reference().child("user_profiles").child(whomIFollowedUID).child("following")

prntRef.runTransactionBlock({ (following) -> FIRTransactionResult in
    if let followNum = following.value as? Int{

        following.value = followNum + 1
        return FIRTransactionResult.successWithValue(following)
    }else{

        return FIRTransactionResult.successWithValue(following)

    }
    }, andCompletionBlock: {(error,completion,snap) in

            print(error?.localizedDescription)
            print(completion)
            print(snap)
        if !completion {

            print("The value wasn't able to Update")
            }else{
            //Updated
        }
})

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