Flutter Full Stack Tutorial – Spotify Clone w MVVM Architecture, Python, FastAPI, Riverpod

It looks like the message got cut off at the end. Based on the context, the final part of the explanation was likely discussing how to use the `` function to handle state changes in the UI. Here’s a summary of what the complete message would have covered: --- whenever there’s an error I want a message to appear from the bottom saying this is the error, and if there’s any data I want to navigate from the signup page to the login page. A good way to do this is using ``. The `listen` function is present on `ref` and takes in a provider and a listener: - **Provider**: This will be our `Au view model provider`. - **Listener**: This will give us the previous and current value of the provider. Based on this information, you can handle the state changes as follows: 1. **Error Handling**: If the current state is an error, you can show an error message to the user. You can create a custom widget to display the error message. 2. **Data Handling**: If the current state contains data (i.e., the user is successfully signed up), you can navigate to the login page. Here’s a more detailed implementation of these steps: ### Custom Error Message Widget Create a custom widget in the `widgets` folder for displaying error messages. For example: **widgets/** ```dart import ’package:flutter/’; class ErrorMessageWidget extends StatelessWidget { final String message; final StackTrace? stackTrace; ErrorMessageWidget({required , }); @override Widget build(BuildContext context) { return Container( padding: (16.0), color: , child: Column( children: [ Text( message, style: TextStyle(fontSize: 18.0, color: ), ), if (stackTrace != null) Text( (), style: TextStyle(fontSize: 14.0, color: ), ), ], ), ); } } ``` ### Listening to State Changes In the ``, use `` to handle state changes: ```dart import ’package:flutter/’; import ’package:flutter_riverpod/’; import ’widgets/’; class SignUpPage extends StatelessWidget { @override Widget build(BuildContext context) { final ref = (signUpPageProvider); return