Example for firebase DB #24

2025-09-21 16:02:05 +08:00 · 2019-10-11 17:35:44 +05:30
parent 3f2e0b5ad5
commit 90283b6d5c
57 changed files with 1459 additions and 0 deletions
--- a/using_firebase_db/lib/main.dart
+++ b/using_firebase_db/lib/main.dart
@ -0,0 +1,137 @@
+import 'dart:async';
+import 'package:firebase_database/firebase_database.dart';
+
+import 'package:flutter/material.dart';
+
+class Note {
+  String id;
+  String content;
+  String createdOn;
+
+  Note(content) {
+    this.content = content;
+    this.createdOn = DateTime.now().toString();
+  }
+}
+
+void main() => runApp(MyApp());
+
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Firebase Demo',
+      theme: ThemeData(
+        primarySwatch: Colors.blue,
+      ),
+      home: MyHomePage(title: 'Firebase demo'),
+    );
+  }
+}
+
+class MyHomePage extends StatefulWidget {
+  MyHomePage({Key key, this.title}) : super(key: key);
+
+  final String title;
+  @override
+  _MyHomePageState createState() => _MyHomePageState();
+}
+
+class _MyHomePageState extends State<MyHomePage> {
+  final notesRef = FirebaseDatabase.instance.reference().child('notes');
+  final inputController = TextEditingController();
+  StreamSubscription<Event> _noteAddedStream;
+  var items;
+
+  @override
+  void initState() {
+    super.initState();
+
+    items = new List();
+    _noteAddedStream =
+        notesRef.orderByChild("created_on").onChildAdded.listen(_onNoteAdded);
+  }
+
+  // Creates a new child under notes in the database
+  void _addNote() {
+    var note = Note(inputController.text);
+    inputController.text = "";
+    if (note.content.isNotEmpty) {
+      notesRef.push().set({
+        'content': note.content,
+        'created_on': note.createdOn,
+      });
+    }
+  }
+
+  // Fired whenever the database sees a new child under the notes
+  // database reference
+  void _onNoteAdded(Event event) {
+    setState(() {
+      var note = Note(event.snapshot.value["content"]);
+      note.id = event.snapshot.key;
+      note.createdOn = event.snapshot.value["created_on"];
+      items.add(note);
+    });
+  }
+
+  // The note has to be cleared from the database and the local list
+  void _deleteNote(int position) {
+    String id = items[position].id;
+    notesRef.child(id).remove().then((_) {
+      setState(() {
+        items.removeAt(position);
+      });
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("Using Firebase DB"),
+      ),
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: <Widget>[
+            Container(
+              padding: EdgeInsets.all(15.0),
+              child: TextField(
+                style: new TextStyle(
+                    fontSize: 24.0, height: 2.0, color: Colors.black),
+                decoration: InputDecoration(
+                    border: InputBorder.none, hintText: 'Add a note'),
+                controller: inputController,
+              ),
+            ),
+            Expanded(
+              child: SizedBox(
+                height: 200.0,
+                child: ListView.builder(
+                    itemCount: items.length,
+                    padding: const EdgeInsets.all(10.0),
+                    itemBuilder: (context, position) {
+                      return Card(
+                        child: ListTile(
+                          leading: Icon(Icons.note),
+                          title: Text(items[position].content),
+                          onLongPress: () {
+                            _deleteNote(position);
+                          },
+                        ),
+                      );
+                    }),
+              ),
+            ),
+          ],
+        ),
+      ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: _addNote,
+        tooltip: 'Add Note',
+        child: Icon(Icons.add),
+      ),
+    );
+  }
+}