Provider exposes incorrect values with Streams

Question

I am using Provider with to expose some parameters to Widgets deep down a tree. The Widgets are built from Streambuilder, i.e. Firebase documents

However, Provider does not seem to be exposing the correct value

A very simplified version of my code:

import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:provider/provider.dart';

class Parameters {
  Parameters(this.documentId);
  final String documentId;
}

class Widget1 extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return StreamBuilder<QuerySnapshot>(
        stream: mystream, //Query the Firebase for a bunch of Documents
        builder: (context, snapshot) {
          if (snapshot.hasError) {
            return Text('Error processing data feed');
          }
          switch (snapshot.connectionState) {
            case ConnectionState.waiting:
              {
                return CircularProgressIndicator();
              }
              break;
            default:
              {
                var _messages = snapshot.data.documents;

                return ListView.builder(
                    itemCount: _messages.length,
                    itemBuilder: (context, index) {
                      return Provider<Parameters>(
                          builder: (context) =>
                              Parameters(_messages[index].documentID),
                          child: AnotherWidget());
                    });
              }
          }
        });
  }
}

class AnotherWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    Parameters param = Provider.of<Parameters>(context);
    return Text(param.documentId);
  }
}

This works perfectly fine when the Widgets are built for the first time. However, when a new document is inserted AnotherWidget shows the document Id of previous document

How do I get the correct document ID when the stream is updated?

Note: I am aware I can simply pass the document as a parameter. However I need the parameter deep down the widget tree of AnotherWidget

Solution

Looks like this is precisely why ProxyProvider was introduced

https://pub.dev/documentation/provider/latest/provider/ProxyProvider-class.html Quoting the important note:

As opposed to the builder parameter of Provider, builder may be called more than once. It will be called once when the widget is mounted, then once whenever any of the InheritedWidget which ProxyProvider depends emits an update

By wrapping AnotherWidget with MultiProvider containing ProxyProvider (as below) solves the problem

child: MultiProvider(
                        providers: [
                            Provider.value(value: _messages[index].documentID),
                            ProxyProvider<String, Parameters>(
                              builder: (context, documentId, parameters) => Parameters(documentId),
                            ),
                          ],
                          child: AnotherWidget()));