Update Firebase database object with multiple uploads - swift

Question

I have a post object that has two parts (1)photo and (2)video. In the posting flow the user selects and image, then hits next to the next screen where they select a video. Both the photo and the video are uploaded to Firebase as part of a post object. See the simple design.
wireframe design
I'm getting stuck creating the post object with both the photo url and the video url. I've tried:
1- After selecting the photo and moving to the next step, I upload the photo to Firebase storage and create the post object in the database with the photo url and an empty string for the video url.
2-Then after selecting the video, I upload the video to Firebase storage, and try to update the existing post object with the video url...
However I have not been able to update the correct post object, and don't know how I can retrieve the postByAutoID in order to update the correct post.
Here is what the database object looks like:
I tried to pass the photoURL forward to the second part of the post, but the upload and generation of the url is not complete by the time the variable gets passed.
Any help is appreciated!

Answer 1

With web, or JavaScript, uploads to firebase cloud storage return promises, therefore Promise.all an array of individual uploads.
As for swift, or IOS, you will have to push each upload (.putData) to memory then iterate/loop over them.
See Upload Files on iOS which provides a starting point and add your loop/iteration.
// Data in memory
let data = Data()
// Create a reference to the file you want to upload
let riversRef = storageRef.child("images/rivers.jpg")
// Upload the file to the path "images/rivers.jpg"
let uploadTask = riversRef.putData(data, metadata: nil) { (metadata, error) in
guard let metadata = metadata else {
// Uh-oh, an error occurred!
return
}
// Metadata contains file metadata such as size, content-type.
let size = metadata.size
// You can also access to download URL after upload.
riversRef.downloadURL { (url, error) in
guard let downloadURL = url else {
// Uh-oh, an error occurred!
return
}
}
}