Flutter local database nice animal

Flutter local database nice animal :

This flutter tutorial post is generic (query, insert, insertAll, insertOrUpdateAll, update, delete, close, opern and getAll) sqflite local database and pagination.

dependencies:
sqflite:
http:

pagination :

Here quantity is null then value 10 consider.
final response = await http.get(‘https://shibe.online/api/${describeEnum(type)}?count=${quantity ?? 10}’);

sqflite flutter :

abstract class BaseRepository<T> {
  Future<R> query<R>(BaseSpecification<R> specification);
  Future<T> insert(T entity, {reload: true});
  Future insertAll(List<T> entities);
  Future<T> insertOrUpdate(T entity);
  Future insertOrUpdateAll(List<T> entities);
  Future update(T entity);
  Future delete(T entity);
  Future close();
  Future open();
  Future<List<T>> getAll();

  Future<String> getAppDBPath() async {
    var databasesPath = await getDatabasesPath();
    // Make sure the directory exists
    try {
      await Directory(databasesPath).create(recursive: true);
    } catch (_) {}

    return join(databasesPath, Constants.databaseName);
  }
}

class NicePictureRepository extends BaseRepository<NicePicture> {
  static const String tableAnimalPicture = 'NicePicture';
  static const String columnPictureURL = "picture_url";
  static const String columnType = "animal_type";

  Database db;

  static Map<String, dynamic> entityToMap(NicePicture picture) {
    return {
      columnPictureURL: picture.url,
      columnType: describeEnum(picture.type)
    };
  }

  static NicePicture mapToEntity(Map<String, dynamic> map) {
    var type = map[columnType];
    return NicePicture(map[columnPictureURL] as String,
        AnimalType.values.firstWhere((it) => describeEnum(it) == type));
  }

  @override
  Future<List<NicePicture>> getAll() async {
    var list = await db.query(tableAnimalPicture);
    return list.map((map) => mapToEntity(map)).toList();
  }

  @override
  Future<R> query<R>(BaseSpecification<R> specification) async {
    return specification.toResults(db);
  }

  @override
  Future<NicePicture> insert(NicePicture entity, {reload: true}) async {
    await db.insert(tableAnimalPicture, entityToMap(entity));
    return entity;
  }

  @override
  Future<NicePicture> insertOrUpdate(NicePicture entity, {reload: true}) async {
    await db.insert(tableAnimalPicture, entityToMap(entity),
        conflictAlgorithm: ConflictAlgorithm.replace);
    return entity;
  }

  @override
  Future insertAll(List<NicePicture> entities) async {
    var transactions = entities.map((entity) => insert(entity));
    await Future.wait(transactions);
  }

  @override
  Future insertOrUpdateAll(List<NicePicture> entities) async {
    var transactions = entities.map((entity) => insertOrUpdate(entity));
    await Future.wait(transactions);
  }

  @override
  Future update(NicePicture entity) async {
    await db.update(tableAnimalPicture, entityToMap(entity));
  }

  @override
  Future delete(NicePicture entity) async {
    await db.delete(tableAnimalPicture,
        where: '$columnPictureURL = ?', whereArgs: [entity.url]);
  }

  @override
  Future close() async {
    db.close();
  }

  @override
  Future open() async {
    var path = await getAppDBPath();
    db = await openDatabase(path, version: 1, onCreate: _onCreate);
  }

  Future _onCreate(Database db, int version) async {
    await db.execute('''
      CREATE TABLE $tableAnimalPicture ( 
        $columnPictureURL TEXT PRIMARY KEY NOT NULL,
        $columnType TEXT NOT NULL
      )
    ''');
  }
}

Screenshot :

Flutter local database nice animal

Packages :

  • base Package
  • communicationlayer Package
  • model Package
  • ui Package

Inside base Package

base_repository.dart

import 'dart:io';

import 'package:nice_animals/ui/util/app_constants.dart';
import 'package:nice_animals/base/base_specification.dart';
import 'package:path/path.dart';
import 'package:sqflite/sqflite.dart';

abstract class BaseRepository<T> {
  Future<R> query<R>(BaseSpecification<R> specification);

  Future<T> insert(T entity, {reload: true});

  Future insertAll(List<T> entities);

  Future<T> insertOrUpdate(T entity);

  Future insertOrUpdateAll(List<T> entities);

  Future update(T entity);

  Future delete(T entity);

  Future close();

  Future open();

  Future<List<T>> getAll();

  Future<String> getAppDBPath() async {
    var databasesPath = await getDatabasesPath();
    // Make sure the directory exists
    try {
      await Directory(databasesPath).create(recursive: true);
    } catch (_) {}

    return join(databasesPath, Constants.databaseName);
  }
}

base_specification.dart

import 'package:sqflite/sqflite.dart';

abstract class BaseSpecification<T> {
  Future<T> toResults(Database db);
}

Inside communicationlayer Package

all_by_type.dart

import 'package:flutter/foundation.dart';
import 'package:nice_animals/base/base_specification.dart';
import 'package:nice_animals/model/nice_picture.dart';
import 'package:sqflite/sqflite.dart';
import 'nice_picture_repository.dart';

class AllByType extends BaseSpecification<List<NicePicture>> {
  AnimalType type;

  AllByType(AnimalType type) {
    this.type = type;
  }

  @override
  Future<List<NicePicture>> toResults(Database db) async {
    var results = await db.query(NicePictureRepository.tableAnimalPicture,
        where: '${NicePictureRepository.columnType} = ?',
        whereArgs: [describeEnum(type)]);

    return results.map((it) => NicePictureRepository.mapToEntity(it)).toList();
  }
}

nice_picture_repository.dart

import 'package:flutter/foundation.dart';
import 'package:nice_animals/base/base_repository.dart';
import 'package:nice_animals/base/base_specification.dart';
import 'package:nice_animals/model/nice_picture.dart';
import 'package:sqflite/sqflite.dart';

class NicePictureRepository extends BaseRepository<NicePicture> {
  static const String tableAnimalPicture = 'NicePicture';
  static const String columnPictureURL = "picture_url";
  static const String columnType = "animal_type";

  Database db;

  static Map<String, dynamic> entityToMap(NicePicture picture) {
    return {
      columnPictureURL: picture.url,
      columnType: describeEnum(picture.type)
    };
  }

  static NicePicture mapToEntity(Map<String, dynamic> map) {
    var type = map[columnType];
    return NicePicture(map[columnPictureURL] as String,
        AnimalType.values.firstWhere((it) => describeEnum(it) == type));
  }

  @override
  Future<List<NicePicture>> getAll() async {
    var list = await db.query(tableAnimalPicture);
    return list.map((map) => mapToEntity(map)).toList();
  }

  @override
  Future<R> query<R>(BaseSpecification<R> specification) async {
    return specification.toResults(db);
  }

  @override
  Future<NicePicture> insert(NicePicture entity, {reload: true}) async {
    await db.insert(tableAnimalPicture, entityToMap(entity));
    return entity;
  }

  @override
  Future<NicePicture> insertOrUpdate(NicePicture entity, {reload: true}) async {
    await db.insert(tableAnimalPicture, entityToMap(entity),
        conflictAlgorithm: ConflictAlgorithm.replace);
    return entity;
  }

  @override
  Future insertAll(List<NicePicture> entities) async {
    var transactions = entities.map((entity) => insert(entity));
    await Future.wait(transactions);
  }

  @override
  Future insertOrUpdateAll(List<NicePicture> entities) async {
    var transactions = entities.map((entity) => insertOrUpdate(entity));
    await Future.wait(transactions);
  }

  @override
  Future update(NicePicture entity) async {
    await db.update(tableAnimalPicture, entityToMap(entity));
  }

  @override
  Future delete(NicePicture entity) async {
    await db.delete(tableAnimalPicture,
        where: '$columnPictureURL = ?', whereArgs: [entity.url]);
  }

  @override
  Future close() async {
    db.close();
  }

  @override
  Future open() async {
    var path = await getAppDBPath();
    db = await openDatabase(path, version: 1, onCreate: _onCreate);
  }

  Future _onCreate(Database db, int version) async {
    await db.execute('''
      CREATE TABLE $tableAnimalPicture ( 
        $columnPictureURL TEXT PRIMARY KEY NOT NULL,
        $columnType TEXT NOT NULL
      )
    ''');
  }
}

shibe_service.dart

import 'dart:async';
import 'dart:convert';

import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
import 'package:nice_animals/model/nice_picture.dart';

class ShibeService {
  static Future<List<NicePicture>> get(AnimalType type, {int quantity}) async {

    final response = await http.get(
        'https://shibe.online/api/${describeEnum(type)}?count=${quantity ?? 10}');

    // ignore: avoid_as
    final jsonResponse = json.decode(response.body) as List<dynamic>;

    return jsonResponse
        .cast<String>()
        .map((url) => NicePicture(url, type))
        .toList();
  }
}

Inside model Package

nice_picture.dart

enum AnimalType { shibes, cats, birds }

class NicePicture {
  String url;
  AnimalType type;

  NicePicture(String url, AnimalType type) {
    this.url = url;
    this.type = type;
  }
}

Inside ui Package

There are three Packages inside ui package

  • pages Package
  • util Package
  • widgets Package

Inside pages Package

animal_page.dart

import 'package:flutter/material.dart';
import 'package:nice_animals/communicationlayer/all_by_type.dart';
import 'package:nice_animals/communicationlayer/nice_picture_repository.dart';
import 'package:nice_animals/communicationlayer/shibe_service.dart';
import 'package:nice_animals/model/nice_picture.dart';
import 'package:nice_animals/ui/util/listener/bottom_reach.dart';
import 'package:nice_animals/ui/util/nice_navigator.dart';
import 'package:nice_animals/ui/widgets/animal_card.dart';
import 'package:nice_animals/ui/widgets/app_loader.dart';

class AnimalListScreen extends StatefulWidget {
  const AnimalListScreen(this.type) : super();

  final AnimalType type;

  @override
  _AnimalListScreenState createState() => _AnimalListScreenState(type);
}

class _AnimalListScreenState extends State<AnimalListScreen>
    with AutomaticKeepAliveClientMixin<AnimalListScreen> {

  _AnimalListScreenState(this.type);

  final repository = NicePictureRepository();
  ScrollController listController = ScrollController();
  bool hasLoaded = false;
  bool isLoadingMore = false;
  List<NicePicture> animals = [];
  AnimalType type;


  @override
  bool get wantKeepAlive => true;

  void loadMoreShibes() async {
    setState(() {
      isLoadingMore = true;
    });

    final loadedAnimals = await ShibeService.get(type);

    setState(() {
      animals = animals + loadedAnimals;
      isLoadingMore = false;
    });
  }

  void loadShibes() async {
    await repository.open();
    var loadedAnimals = await repository.query(AllByType(type));
    if (loadedAnimals.isEmpty) {
      loadedAnimals = await ShibeService.get(type);
    }
    await repository.insertOrUpdateAll(loadedAnimals);
    await repository.close();

    setState(() {
      animals = loadedAnimals;
      hasLoaded = true;
    });
  }

  @override
  void initState() {
    super.initState();
    if (!hasLoaded) {
      loadShibes();

      OnBottomReach(listController, () {
        if (!isLoadingMore) {
          loadMoreShibes();
        }
      }, sensitivity: 400.0);
    }
  }

  void _openPicture(int index) {
    NiceNavigator.goToGallery(context, initialPage: index, list: animals);
  }

  @override
  Widget build(BuildContext context) {
    if (!hasLoaded) {
      return Center(
          child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[AppLoader()],
      ));
    } else {
      return GridView.count(
        crossAxisCount: 2,
        controller: listController,
        children: List.generate(animals.length, (index) {
          return Container(
            padding: const EdgeInsets.all(3.5),
            child: AnimalCard(
                picture: animals[index],
                onTap: () {
                  _openPicture(index);
                }),
          );
        }),
      );
    }
  }
}

nice_fullscreen_gallery.dart

import 'package:flutter/material.dart';
import 'package:nice_animals/model/nice_picture.dart';
import 'package:nice_animals/ui/util/nice_navigator.dart';

class NiceFullScreenGallery extends StatefulWidget {
  const NiceFullScreenGallery({@required this.initialPage, @required this.list})
      : super();

  final int initialPage;
  final List<NicePicture> list;

  @override
  _NiceFullScreenGalleryState createState() =>
      _NiceFullScreenGalleryState(initialPage, list);
}

class _NiceFullScreenGalleryState extends State<NiceFullScreenGallery> {
  _NiceFullScreenGalleryState(this.initialPage, this.list) : super() {
    controller = PageController(initialPage: initialPage);
    NiceNavigator.setStatusBarState(shown: false);
  }

  List<NicePicture> list;
  int initialPage;
  PageController controller;


  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () {
        NiceNavigator.setStatusBarState(shown: true);
        Navigator.pop(context, true);
      },
      child: Scaffold(
        backgroundColor: Colors.black,
        body: PageView.builder(
          controller: controller,
          physics: const AlwaysScrollableScrollPhysics(),
          itemBuilder: (BuildContext context, int index) {
            return Image.network(
              list[index].url,
              fit: BoxFit.cover,
            );
          },
        ),
      ),
    );
  }
}

nice_home_screen.dart

import 'package:flutter/material.dart';
import 'package:nice_animals/model/nice_picture.dart';
import 'package:nice_animals/ui/pages/animal_page.dart';

class NiceHomeScreen extends StatefulWidget {
  @override
  _NiceHomeState createState() => _NiceHomeState();
}

class _NiceHomeState extends State<NiceHomeScreen>
    with SingleTickerProviderStateMixin {
  TabController _tabController;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(vsync: this, initialIndex: 1, length: 3);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Nice Animals'),
        elevation: 0.7,
        bottom: TabBar(
          controller: _tabController,
          indicatorColor: Colors.accents.first,
          tabs: const <Widget>[
            Tab(text: 'Cats'),
            Tab(text: 'Shibes'),
            Tab(text: 'Birbs'),
          ],
        ),
      ),
      body: TabBarView(
        controller: _tabController,
        children: const <Widget>[
          AnimalListScreen(AnimalType.cats),
          AnimalListScreen(AnimalType.shibes),
          AnimalListScreen(AnimalType.birds),
        ],
      ),
    );
  }
}

nice_splash_screen.dart

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:nice_animals/ui/util/nice_navigator.dart';
import 'package:nice_animals/ui/widgets/app_loader.dart';

class SplashScreenPage extends StatefulWidget {
  const SplashScreenPage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _SplashScreenPageState createState() => _SplashScreenPageState();
}

class _SplashScreenPageState extends State<SplashScreenPage> {
  @override
  void initState() {
    super.initState();
    Timer(Duration(seconds: 2), () => NiceNavigator.goToHome(context));
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
        backgroundColor: Colors.amber,
        body: Stack(
          children: <Widget>[
            Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  Image.asset('assets/main_icon.png', width: 100.0),
                  Text(
                    'Nice Animals',
                    style: Theme.of(context).textTheme.display1,
                  ),
                  Container(
                    margin: const EdgeInsets.only(top: 40.0),
                    child: AppLoader(),
                  )
                ],
              ),
            ),
          ],
        ));
  }
}

Inside util Package

  • listener Package
  • app_constants.dart
  • nice_navigator.dart

app_constants.dart

class Constants {
  static const databaseName = 'nice.db';
}

nice_navigator.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:nice_animals/model/nice_picture.dart';
import 'package:nice_animals/ui/pages/nice_fullscreen_gallery.dart';

class NiceNavigator {
  static void goToHome(BuildContext context) {
    Navigator.pushReplacementNamed(context, '/home');
  }

  static void goToGallery(BuildContext context,
      {@required int initialPage, @required List<NicePicture> list}) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) =>
            NiceFullScreenGallery(
              initialPage: initialPage,
              list: list,
            ),
      ),
    );
  }

  static void setStatusBarState({@required bool shown}) {
    if (shown) {
      SystemChrome.setEnabledSystemUIOverlays(SystemUiOverlay.values);
    } else {
      SystemChrome.setEnabledSystemUIOverlays([]);
    }
  }
}

Inside listener Package

bottom_reach.dart

import 'package:flutter/material.dart';

class OnBottomReach {
  OnBottomReach(ScrollController container, VoidCallback callback,
      {double sensitivity: 200.0}) {
    container.addListener(() {
      final maxScroll = container.position.maxScrollExtent;
      final currentScroll = container.position.pixels;
      if (maxScroll - currentScroll <= sensitivity) {
        callback();
      }
    });
  }
}

Inside widgets Package

animal_card.dart

import 'package:flutter/material.dart';
import 'package:nice_animals/model/nice_picture.dart';

class AnimalCard extends StatelessWidget {
  const AnimalCard({@required this.picture, this.onTap}) : super();

  final NicePicture picture;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: ClipRRect(
          borderRadius: BorderRadius.circular(2.0),
          child: Image.network(
            picture.url,
            fit: BoxFit.cover,
          )),
    );
  }
}

app_loader.dart

import 'package:flutter/material.dart';

class AppLoader extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return const CircularProgressIndicator(
        value: null,
        valueColor: AlwaysStoppedAnimation<Color>(Colors.black54)
    );
  }
}

Outside All Packages

main.dart

import 'package:flutter/material.dart';
import 'package:nice_animals/ui/pages/nice_home_screen.dart';
import 'package:nice_animals/ui/pages/nice_splash_screen.dart';
import 'package:sqflite/sqflite.dart';

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

var routes = <String, WidgetBuilder>{
  "/home": (context) => NiceHomeScreen(),
};

class MyApp extends StatelessWidget {
  MyApp() {
    assert(() {
      Sqflite.setDebugModeOn(true);
      return true;
    }());
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Flutter Tutorial',
      theme: ThemeData(
        primarySwatch: Colors.amber,
      ),
      home: SplashScreenPage(title: 'Nice splash page'),
      routes: routes,
    );
  }
}

pubspec.yaml

name: nice_animals
description: A new Flutter application.

version: 1.0.0+1

environment:
  sdk: ">=2.1.0 <3.0.0"

dependencies:
  sqflite:
  flutter:
    sdk: flutter

  cupertino_icons:
  http:
  cached_network_image: ^1.1.3

dependency_overrides:
  http:

dev_dependencies:
  flutter_test:
    sdk: flutter

flutter:
  uses-material-design: true

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