downloadURL from Firebase Storage is nil after successfully uploading a file - swift

Question

I'm new to firebase and I'm facing a problem here.
I have successfully uploaded my image to firebase storage already, however, I need to get the downloadurl at once and post it to the database. And I'm not sure why it doesn't work within that closure.
The following is my code:-
func CreateNewChatRoom(user: User, caption: String, data: Data){
let filePath = "\(user.uid)/\(Int(NSDate.timeIntervalSinceReferenceDate)).jpg"
let metaData = StorageMetadata()
metaData.contentType = "image/jpg"
let reference = storageRef.child(filePath)
reference.putData(data, metadata: metaData) { (metadata, error) in
if let error = error {
print("\(error.localizedDescription)")
return
}
reference.downloadURL(completion: { (url, error) in
if let error = error{
print("Error : \(error.localizedDescription)")
return
}
else{
if let downloadURL = url?.absoluteString {
let idRoom = self.BASE_REF.child("rooms").childByAutoId()
idRoom.setValue(["caption":caption, "thumbnailUrlFromStorage": self.storageRef.child(metadata!.path!).description,"fileUrl": downloadURL])
}
}
})
}
}

Answer 1

I have the same problem, and I found the following solution,
I hope it is useful to someone.
Swift 5
import FirebaseAuth
import FirebaseStorage
import FirebaseFirestore
typealias AddStoryResult = (Bool, Error?) -> Void
typealias UploadImageResult = (StorageMetadata?, Error?) -> Void
class StoryFirebaseAPI {
static let storage = Storage.storage()
static var downloadUrlString: URL?
var image: UIImage?
let photoUri = "smth uri path"
uploadImage(image, photoUriString: photoUri) { (metadata: StorageMetadata?, error: Error?) in
guard let metadata = metadata else {
if let error = error {
print("Error occured: \(error)")
}
completion(false, error)
return
}
// and at this point I have print(downloadUrlString)
completion(true, nil)
}
}
extension StoryFirebaseAPI {
func uploadImage(_ image: UIImage, photoUriString: String, completion: #escaping UploadImageResult) {
guard let imageData = image.jpegData(compressionQuality: 0.5) else {
print("smth error")
completion(nil, nil)
return
}
let storageRef = storage.reference().child(photoUriString)
let imageMetadata = StorageMetadata()
imageMetadata.contentType = "image/jpeg"
storageRef.putData(imageData, metadata: imageMetadata) { (storageMetadata, error) in
if let error = error {
print("Error: \(error.localizedDescription)")
completion(nil, error)
return
}
guard let unwrappedMetadata = storageMetadata else {
print("smth error")
print("Error: \(error?.localizedDescription ?? "")")
completion(nil, error)
return
}
storageRef.downloadURL { url, error in
if let error = error {
print("Error: \(error.localizedDescription)")
completion(nil, error)
return
} else {
if let url = url {
downloadUrlString = url
completion(unwrappedMetadata, nil)
}
}
}
print("Image uploaded successfully")
}
}
}