Firebase - Unable to execute call to backend - ios

Question

I am working on a function that handles user registration and in the process, check if the selected username entered by the user is taken or not to inform the user to select a different one. I have the below code to accomplish this scenario:
#IBAction func proceedPressed(sender: AnyObject) {
/**********************Perform Validation************************/
if(self.emailTxtField.text != "" && self.passwordTxtField.text != "")
{
print("Email and Password not empty")
self.usernameValidation({(result) -> Void in
if(result == false)
{
print("Result False")
self.usernameErrorLabel.text = "Username Taken"
}else{
print("Result True")
//Username is available...Proceed
self.usernameErrorLabel.text = ""
FIRAuth.auth()?.createUserWithEmail(self.emailTxtField.text!, password: self.passwordTxtField.text!) { (user, error) in
if(error == nil)
{
print("Creating User with Email")
/*Create the user object as submitted*/
self.dbReference.child("users").child(user!.uid).setValue(["username": self.emailTxtField.text!,"name":self.nameTxtField.text!, "email":self.emailTxtField.text!, "mobile":self.mobileTxtField.text!, "homeAddress":"N", "workAddress":"N", "otherAddress":"N", "profilePictureRef":"N","telephone":"0","friendsCount":0, "retailersCount":0])
}else{
print("Error occured: \(error?.description)")
}
}//end of createUserWithEmail
}
})
}else{
print("Error: Email or Password field is empty")
}
}
and to check the username:
func usernameValidation(completion: (result: Bool) -> Void)
{
print("Username is: \(self.usernameTxtField.text!)")
dbReference.child("usernamesTaken").queryOrderedByValue().queryEqualToValue(self.usernameTxtField.text!).observeEventType(.Value, withBlock: { (snapshot: FIRDataSnapshot!) -> Void in
print(snapshot.childrenCount)
if(snapshot.childrenCount == 0)
{
print("result is true in username validation")
//Username Available
completion(result:true)
}else{
print("result is false in username validation")
//Username Taken
completion(result:false)
}
})
}
The problem with the above is that the full code doesn't seem to execute. When button pressed, I get the following messages in console:
- Email and Password not empty
- Username is: [value entered in usernameTxtField.text
and then nothing more. Although I wrote many print statements to try and see where this is stopping, but this is the furthest the code went in terms of printing the statements.
Is there something wrong here that I am missing out?
Thanks in advance.

Answer 1

I did some more testing and then discovered the issue through the xcode console. I copied the following from the firebase website to test fetching the data:
ref.child("users").child(userID!).observeSingleEventOfType(.Value, withBlock: { (snapshot) in
// Get user value
let username = snapshot.value!["username"] as! String
let user = User.init(username: username)
// ...
}) { (error) in
print(error.localizedDescription)
}
The above showed an error that is "Permission Denied". Following that I edited the Rules in the database section in the console and allowed .read and .write and that did it. I thought I would post the details just in case someone else gets stuck.