how to show error when trying to add/upload data to firebase in flutter when user is offline?

Question

I am basically trying to show an alert dialog when a user try to add a document or upload an image to firestore cloud/firebase storage. I tried that with try and catch blocks as well as .catchError() but it did not work, and it basically do this after getting an internet connection. what i want to do is to show an alert dialog and cancel the process even the user gets a connection back (he have to repeat the process of uploading again). here is a sample of my code:

this is for picking and uploading an image:

 Future _getImage(bool isCamera) async {
    var pickedImage;
    try {
      if (isCamera)
        pickedImage =
            await picker.getImage(source: ImageSource.camera, imageQuality: 20);
      else
        pickedImage = await picker.getImage(
            source: ImageSource.gallery, imageQuality: 20);

      if (pickedImage != null) {
        _uploadAndSetUrl(File(pickedImage.path));
      }
    } catch (e) {
      print('error here');
    }
  }

  Future _uploadAndSetUrl(File image) async {
    try {
      _uploadingStatus(true);
      StorageUploadTask uploadTask = _bookImageRef.putFile(image);
      StorageTaskSnapshot taskSnapshot = await uploadTask.onComplete;
      String downloadAddress = await _bookImageRef.getDownloadURL();
      _uploadingStatus(false);
      setState(() {
        _imageUrl = downloadAddress;
      });
      print(_imageUrl);
    } on PlatformException catch (e) {
      print('error: $e');
    } catch (e) {
      print('No image added');
    }
  }

and there is another method for adding a document into firestore cloud. is there any way to do that?

thank you in advance!

Solution

try this,

import 'dart:io';

Future _getImage(bool isCamera) async {
    var pickedImage;
    try {
      if (isCamera)
        pickedImage =
            await picker.getImage(source: ImageSource.camera, imageQuality: 20);
      else
        pickedImage = await picker.getImage(
            source: ImageSource.gallery, imageQuality: 20);

      if (pickedImage != null) {
      try {
        final result = await InternetAddress.lookup('google.com');
      if (result.isNotEmpty && result[0].rawAddress.isNotEmpty) 
        _uploadAndSetUrl(File(pickedImage.path));
       
    } on SocketException catch (_) {
    showDialog(
          context: context,
          builder: (context) => AlertDialog(
            title: Text("Connection Error !"),
            content: Text("Please connect to the internet."),
          )
      );
 }
        
      }
    } catch (e) {
      print('error here');
    }
  }

Comments

[Niteesh]

let me know if this helps