Firebase Upload URL to real time database - swift

Question

I'm trying to upload image url from Firebase Storage to Realtime database.
Here's the code
#IBOutlet weak var jobTitle: UITextField!
#IBOutlet weak var companyName: UITextField!
#IBOutlet weak var jobLocation: UITextField!
#IBOutlet weak var ImageView1stPoster: UIImageView!
var imageUploaded = Data()
var URLtoRealtime = ""
func addPost() {
ref.child("Poster").childByAutoId().setValue(["jobName": jobTitle.text as Any,
"companyTitle": companyName.text as Any,
"jobLocation": jobLocation.text as Any,
"firstPoster": URLtoRealtime as Any,
/*,
"timeStamp":[".sv":"timestamp"]*/]
as[String:Any])
}
// DoneButton to submit everthing :)
#IBAction func DoneButton(_ sender: Any) {
uploadImageToFirebase(imageData: imageUploaded)
createAlert(title: "Post has been submitted", message: "Going to home page")
addPost()
}
func uploadImageToFirebase(imageData: Data) {
// References and vars
let StorageRefrenece = Storage.storage().reference()
let currentUser = Auth.auth().currentUser
let posterImageRef = StorageRefrenece.child("posters").child(currentUser!.uid).child("posterOne.jpg")
let uploadMetaData = StorageMetadata()
uploadMetaData.contentType = "image/jpeg"
// putData to put data to the server using MetaData to orignize everthing.
posterImageRef.putData(imageData, metadata: uploadMetaData) { (uploadedImageMeta, error) in
if error != nil {
print("Error Took place \(String(describing: error?.localizedDescription))")
return
} else {
print("metaData of uploaded image \(uploadMetaData)")
}
}
posterImageRef.downloadURL { (url, error) in
if (error != nil) {
// Handle any errors
print(error!.localizedDescription)
print("NOOOPPPEEE")
} else {
// Get the download URL for 'images/stars.jpg'
print("Working Good")
let UrlString = url!.absoluteString
print(UrlString)
self.URLtoRealtime = UrlString
}
}
}
I'm trying like to make URLString = URLtoRealtime data and then
add the post to firebase.
but what is happening is that it executes addPost() function before
self.URLtoRealtime = UrlString
I don't know how to make the program to execute the previous line of code before addpost() function.

Answer 1

When the done button is touched, you're asynchronously uploading the image to firebase and downloading the URL. However, as you've pointed out, by the time you addPost, the URL hasn't been downloaded yet – you want to do one after the other.
#IBAction func DoneButton(_ sender: Any) {
uploadImageToFirebase(imageData: imageUploaded) { [weak self] (url, error) in
if let url = url {
createAlert(title: "Post has been submitted", message: "Going to home page")
self?.URLtoRealtime = url.absoluteString
self?.addPost()
} else {
self?.createAlert(title: "Post could not be submitted", message: "Try again")
}
}
}
We can add a completion argument to the upload method so that you can addPost once the upload and download of the URL is finished.
func uploadImageToFirebase(imageData: Data, completion: #escaping (URL?, Error?) -> ()) {
guard let uid = Auth.auth().currentUser?.uid else { return completion(nil, nil) }
let posterImageRef = Storage.storage().reference(withChild: "posters/\(uid)/posterOne.jpg")
let uploadMetaData = StorageMetadata(dictionary: [ "contentType": "image/jpeg" ])
posterImageRef.putData(imageData, metadata: uploadMetaData) { (metadata, error) in
if let ref = metadata?.storageReference {
ref.downloadURL(completion: { (url, error) in
completion(url, error)
})
} else {
completion(nil, error)
}
}
}