Let’s build a Chat App in Flutter

Here’s some basic code to get you started on creating a chat app in Flutter:

import ‘package:flutter/material.dart’;
import ‘package:cloud_firestore/cloud_firestore.dart’;

class ChatApp extends StatefulWidget {
@override
_ChatAppState createState() => _ChatAppState();
}

class _ChatAppState extends State<ChatApp> {
final _textController = TextEditingController();
final _firestore = Firestore.instance;

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(“Chat App”),
),
body: Column(
children: [
Expanded(
child: StreamBuilder(
stream: _firestore.collection(“messages”).snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return Center(
child: CircularProgressIndicator(),
);
}
final messages = snapshot.data.documents.reversed;
List<Widget> messageWidgets = [];
for (var message in messages) {
final messageText = message.data[“text”];
final messageSender = message.data[“sender”];
final messageWidget =
Text(“$messageText from $messageSender”);
messageWidgets.add(messageWidget);
}
return ListView(
reverse: true,
children: messageWidgets,
);
},
),
),
Container(
padding: EdgeInsets.all(10),
child: Row(
children: [
Expanded(
child: TextField(
controller: _textController,
decoration: InputDecoration(
hintText: “Enter your message”,
),
),
),
FlatButton(
onPressed: () {
_firestore.collection(“messages”).add({
“text”: _textController.text,
“sender”: “User”,
});
_textController.clear();
},
child: Text(“Send”),
),
],
),
),
],
),
);
}
}

In the code above, we use the Firestore class from the cloud_firestore package to store the chat messages. The messages are displayed using a StreamBuilder widget, which listens to changes in the messages collection and automatically updates the UI whenever a new message is added. The user can enter a new message using a TextField widget, and send the message by pressing a FlatButton. The messages are stored in the Firestore database as documents, with each document containing a “text” field are stored in the database, as well as to handle user authentication and access control. These are just a few examples, and there are many other features and improvements you can make to create a complete and fully-functional chat app in Flutter.