gk103 gk103 - 2 months ago 25
iOS Question

Follower counter not updating node in firebase

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)

})
}

Answer

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
        }
})