Odtnhj

I followed the startup name generator tutorial in the flutter website and there was no problem.
But then I wanted to add the ability to remove wordpairs from the saved list. That worked too but when a word was removed from the list, the listview wouldn't update and I had to go back to the main page and open the list again to see the effect. I searched for a way to update the listview at the setState function that I delete the wordpair in, but I could't find anything. So after removing the wordpair in the setstate, I just popped the route and pushed it again.
Can anyone suggest a better way?
Thanks

You might be able to do that using a StreamBuilder. Using that, your argument should like the following:

stream: FirebaseDatabase.instance.reference().child(
 "profiles").onValue

As you can see, the onValue will automatically update your screen whenever you delete a value.

Assuming you've just used the main.dart from the startup name generator tutorial, then you can just modify your _buildRow function to add a delete button which will then call setState and modify the _suggestions list like this:

Widget _buildRow(WordPair pair) 
 return ListTile(
 title: Text(
 pair.asPascalCase,
 style: _biggerFont,
 ),
 subtitle: RaisedButton(
 child: Text('delete'),
 onPressed: () 
 setState(() 
 _suggestions.remove(pair);
 );
 ));
 

And here's the full main.dart:

import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget 
 @override
 Widget build(BuildContext context) 
 return MaterialApp(
 title: 'Startup Name Generator',
 home: RandomWords(),
 );
 


class RandomWordsState extends State<RandomWords> 
 final _suggestions = <WordPair>;

 final _biggerFont = const TextStyle(fontSize: 18.0);

 Widget _buildSuggestions() 
 return ListView.builder(
 padding: const EdgeInsets.all(16.0),
 itemBuilder: (context, i) 
 // Add a one-pixel-high divider widget before each row in theListView.
 if (i.isOdd) return Divider();

 final index = i ~/ 2;
 if (index >= _suggestions.length) 
 _suggestions.addAll(generateWordPairs().take(10));
 
 return _buildRow(_suggestions[index]);
 );
 

 Widget _buildRow(WordPair pair) 
 return ListTile(
 title: Text(
 pair.asPascalCase,
 style: _biggerFont,
 ),
 subtitle: RaisedButton(
 child: Text('delete'),
 onPressed: () 
 setState(() 
 _suggestions.remove(pair);
 );
 ));
 

 @override
 Widget build(BuildContext context) 
 return Scaffold(
 appBar: AppBar(
 title: Text('Startup Name Generator'),
 ),
 body: _buildSuggestions(),
 );
 


class RandomWords extends StatefulWidget 
 @override
 RandomWordsState createState() => new RandomWordsState();

I fixed it by making the list of saved pairs a separate stateful widget. I knew this would make the list refresh each time I deleted a pair but I thought the link between the states of the two stateful widgets would be lost and any time I deleted a pair from the list of saved pairs, the favorite icon in the other stateful widget would not update. But amazingly I was wrong. The states are somehow connected. I assume its because they're two stateful widgets on the same stack. I'm beginning to really like flutter.