Uploading multiple Images to firebase in flutter - flutter

Question

I sucessfully Get to pick multiple images from gallery and decided to try uploading to firebase and as well retrieving the image URL. after calling the upload it requested a pass a parameter which i did but it gives an error "The argument type 'List' can't be assigned to the parameter type 'Asset" when i try to specify the index of the parameter i passed it only Saves that image with that particular index.
i also tried a for loop but still it saves only one image and return its url.
How do i get to Upload all the images
Below is how i load the images.
Future<void> loadAssets() async {
List<Asset> resultList = <Asset>[];
resultList = await MultiImagePicker.pickImages(
maxImages: 300,
enableCamera: true,
selectedAssets: images,
cupertinoOptions: const CupertinoOptions(takePhotoIcon: "chat"),
materialOptions: const MaterialOptions(
actionBarColor: "#abcdef",
actionBarTitle: "Example App",
allViewTitle: "All Photos",
selectCircleStrokeColor: "#000000",
));
if (!mounted) return;
setState(() {
images = resultList;
});
}
then i upload the image using the following snippet
Future UploadImage(Asset asset) async {
String fileName = popop;
ByteData byteData = await asset.getByteData();
List<int> imageData = byteData.buffer.asUint8List();
Reference ref = FirebaseStorage.instance.ref().child(fileName);
UploadTask uploadTask = ref.putData(Uint8List.fromList(imageData));
TaskSnapshot snapshot= await uploadTask;
String url= await snapshot.ref.getDownloadURL();
if (kDebugMode) {
print(url);
}
/// After this Update user Profile or add url to collection
return url;
}
used the below code to call/upload a single image out of the list
RaisedButton(
child: const Text("Save Image"),
onPressed: () => UploadImage(images[0]),
),
How to i get to upload all images.
i even tried the for loop below
for(int i=o; i<images.length;i++){
UploadImages(images[i]);
}
But only uploaded a single image

Answer 1

You can iterate over your images like this for example:
final fileNames = <String>[];
for (final image in images) {
final fileName = await uploadImage(image);
fileNames.add(fileName);
}
Not sure whether you really need to call getDownloadUrl() (depends on your use case), but this method creates a public and long-lived url.
If you just want to store a reference in Cloud Firestore for example, you can get the name / fullPath of the respective file from your TaskSnapshot in the uploadImage function as follows:
Future<String> UploadImage(Asset asset) async {
String fileName = popop;
ByteData byteData = await asset.getByteData();
List<int> imageData = byteData.buffer.asUint8List();
Reference ref = FirebaseStorage.instance.ref().child(fileName);
UploadTask uploadTask = ref.putData(Uint8List.fromList(imageData));
TaskSnapshot snapshot= await uploadTask;
// Assuming you are interested in the fullPath use snapshot.ref.fullPath
// For the name use snapshot.ref.name instead
return snapshot.ref.fullPath
}