Flutter: Copy image file from url to firebase

Question

I'm trying to copy a user profile picture from an external service onto my firebase server. So far I have:

final File file = await new File.fromUri(Uri.parse(auth.currentUser.photoUrl)).create();
final StorageReference ref = FirebaseStorage.instance.ref().child("profile_image_${auth.currentUser.uid}.jpg");
final StorageUploadTask uploadTask = ref.put(file);
final Uri downloadUrl = (await uploadTask.future).downloadUrl;

// add user profile picture url to user object
final userReference = FirebaseDatabase.instance
    .reference()
    .child('users/' + auth.currentUser.uid);
userReference.set({'photoUrl': downloadUrl});

The very top line gives me the error: Unsupported operation: Cannot extract a file path from a https URI

What is the correct way to do this? Should this even be done client-side? (Should I just be passing this url to firebase and use a function to download it server-side?)

Solution

File only supports files on a file system. To load content using HTTP use the http package. See also https://flutter.io/networking/

var httpClient = createHttpClient();
var response = await httpClient.get(url); 

and then get the data from response.body, or

var response = await httpClient.readBytes(url);

to get it as binary (Uint8List)

See also https://www.dartdocs.org/documentation/http/0.11.3+14/http/Client-class.html