I am trying to get a username from the user via @IBAction from the UI.
My goal is to check if the username already exists in Firebase. If it does not exists, then register it. If it does exist, I would like to do some other stuff.
Here is my code.
@IBAction func enterUsername(){
let enteredUsername = usernameText!.text!
let namesRef = ref.childByAppendingPath("/usernames/\(enteredUsername)")
namesRef.observeEventType(.Value, withBlock: {
snap in
if (snap.value is NSNull){
let userNameAndUUID = ["Username" : enteredUsername, "UUID" : self.appDelegate.UUID]
namesRef.setValue(userNameAndUUID)
print("first block")
}else {
print("second block")
//do some other stuff
}
})
}
The problem I am having , is that IF the username is unique (does not exist) then BOTH print statements of the if/else are running. Output: first block second block
If the name is NOT unique, it is properly skipping the if portion of the if/else.
Why are both sections of the if/else statement running?
Thanks for any help.
The behavior you're seeing is indeed intended. Since you're attaching an observer, the first if block is being run for a unique name, but within that block, you're setting a value.
This triggers the callback again, which this time, will run through the else block.
The correct way to change this code is to use observeSingleEventOfType
, so that you only read the value once and do not observe it continuously.
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