Not sure where in code to place storageRef.downloadURL - ios

Question

After updating Firebase to Version 4 and correcting all 200 errors, I am left with 2 warnings which make my app crash. I looked up this error and tried the resolution with no success:
storageReference.downloadURLWithCompletion()
I must be doing it wrong:
func setUserInfo(_ user: User!, usersname: String, email: String, password: String, cell: String, data: Data!) {
// Create Path for User Image
let imagePath = "images/riders/\(user.uid)/Profile Pic/userPic.jpg"
// Create image Reference
let imageRef = rDataService.Instance.storageRef.child(imagePath)
// Create Metadata for the image
let metaData = StorageMetadata()
metaData.contentType = "image/jpeg"
// Save the user Image in the Firebase Storage File
imageRef.putData(data as Data, metadata: metaData) { (metaData, error) in
if error == nil {
let changeRequest = user.createProfileChangeRequest()
changeRequest.displayName = usersname
changeRequest.photoURL = metaData?.downloadURL()
changeRequest.commitChanges(completion: { (error) in
if error == nil {
self.saveUser(user, usersname: usersname, email: email, password: password, cell: cell)
} else {
print(error!.localizedDescription)
}
})
} else {
print(error!.localizedDescription)
}
}
}
The error is happening on this line:
changeRequest.photoURL = metaData?.downloadURL()
Edit
After adjustments, getting warning on this line:
if let profilepicMetaData = profilepicMetaData {
error: Value 'profilepicMetaData' was defined but never used; consider replacing with boolean test
App is still crashing:
// Save the user profile Image in the Firebase Storage File
imageRef.putData(data as Data, metadata: profilepicMetaData) { (profilepicMetaData, error) in
if let profilepicMetaData = profilepicMetaData {
imageRef.downloadURL(completion: { (url, error) in
guard let url = url else {
if let error = error {
print(error)
}
return
}
let changeRequest = user.createProfileChangeRequest()
changeRequest.displayName = usersname
changeRequest.photoURL = url
changeRequest.commitChanges(completion: { (error) in
if error == nil {
self.saveUser(user, usersname: usersname, email: email, password: password, year: year, makeAndModel: makeAndModel, cell: cell, plateNo: plateNo)
} else {
print(error!.localizedDescription)
}
})
})
} else {
print(error!.localizedDescription)
}
}
Crash!

Answer 1

You need to use the original storage reference object imageRef to obtain the download url. (please check the comments through the code):
imageRef.putData(data, metadata: profilepicMetaData) {
// use if let to unwrap the metadata returned to make sure the upload was successful. You can use an underscore to ignore the result
if let _ = $0 {
// start the async method downloadURL to fetch the url of the file uploaded
imageRef.downloadURL {
// unwrap the URL to make sure it is not nil
guard let url = $0 else {
// if the URL is nil unwrap the error, print it
if let error = $1 {
// you can present an alert with the error localised description
print(error)
}
return
}
// your createProfileChangeRequest code needs to be run after the download url method completes. If you place it after the closure it will be run before the async method finishes.
let changeRequest = user.createProfileChangeRequest()
changeRequest.displayName = usersname
changeRequest.photoURL = url
changeRequest.commitChanges {
// unwrap the error and print it
if let error = $0 {
// again you might present an alert with the error
print(error)
} else {
// user was updated successfully
self.saveUser(user, usersname: usersname, email: email, password: password, year: year, makeAndModel: makeAndModel, cell: cell, plateNo: plateNo)
}
}
}
} else if let error = $1 {
// present an alert with the error
print(error)
}
}