Invalid call to setPhotoURL: after commitChangesWithCallback - ios

Question

I am trying to implement a user profile view, in which the user chooses a profile image from camera roll and a username. When everything is chosen, the user clicks on a createProfileButton that calls the following function:
#objc func createProfileButtonPressed() {
let user = Auth.auth().currentUser
let uid = Auth.auth().currentUser?.uid
let firebaseStorageRef = Storage.storage().reference().child("profile_picture").child(uid!)
let database = Firestore.firestore()
// settings for disabling warning concerning firestore
let settings = database.settings
settings.areTimestampsInSnapshotsEnabled = true
database.settings = settings
let profileChangeRequest = user?.createProfileChangeRequest()
profileChangeRequest?.displayName = self.usernameTextfield.text
if let profileImage = profilePicture, let imageData = UIImageJPEGRepresentation(profileImage, 0.1) {
firebaseStorageRef.putData(imageData, metadata: nil) { (metadata, error) in
if error != nil {
print("Error:", error!)
return
}
firebaseStorageRef.downloadURL(completion: { (url, error) in
if error != nil {
print("Error:", error!)
return
}
print("Picture URL:", url!)
profileChangeRequest?.photoURL = url
})
}
}
profileChangeRequest?.commitChanges(completion: { (error) in
if error != nil {
print("Error:", error!)
return
}
print("Profile created")
var databaseRef = database.collection("users").addDocument(data: ["uid": uid!, "email": user?.email!, "username": user?.displayName, "profileImageURL": user?.photoURL?.absoluteString], completion: { (error) in
if error != nil {
print("Error storing user", error!)
return
}
print("user successfully stored!")
})
self.navigationController?.popToRootViewController(animated: true)
})
}
I want the users email, username, uid and photoURL stored in a firestore document. However, what I get is this error:
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid call to setPhotoURL: after commitChangesWithCallback:.'
This happens after the popToRootViewController function gets called. Why does this error message show up although I want to set the photoURL before I commit the changes?

Answer 1

Just to expand on ekscrypto's comment. Your call to profileChangeRequest?.photoURL = url is taking place within the download callback, thus it going to be run after your call to commitChanges.
You need to put your commitChanges block inside your callback -
if let profileImage = profilePicture, let imageData = UIImageJPEGRepresentation(profileImage, 0.1) {
firebaseStorageRef.putData(imageData, metadata: nil) { (metadata, error) in
if error != nil {
print("Error:", error!)
return
}
firebaseStorageRef.downloadURL(completion: { (url, error) in
if error != nil {
print("Error:", error!)
return
}
print("Picture URL:", url!)
profileChangeRequest?.photoURL = url
profileChangeRequest?.commitChanges(completion: { (error) in
if error != nil {
print("Error:", error!)
return
}
print("Profile created")
var databaseRef = database.collection("users").addDocument(data: ["uid": uid!, "email": user?.email!, "username": user?.displayName, "profileImageURL": user?.photoURL?.absoluteString], completion: { (error) in
if error != nil {
print("Error storing user", error!)
return
}
print("user successfully stored!")
})
self.navigationController?.popToRootViewController(animated: true)
})
})
}
}