cache_system #

This package for flutter is used to cache files in the device. It can be used to cache images, videos, audios, text and other files. It can also be used to cache files from the internet.

Platform Support #

Install #

• Add cache_systems to your dependencies list in pubspec.yaml file

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^0.1.2
  cache_systems: ^0.0.1

• Run flutter packages get from your root project

• import the package by import 'package:cache_systems/cache_systems.dart';

Usage #

Cache files from the internet #

Firstly initialize the cache system by calling CacheSystem().init() in the main() function. This will initialize the cache system with default values. You can also pass the stalePeriod parameter to the init() function to set the stale period for the cache system. The stale period is the time after which the cache will be considered stale and will be deleted. The default value for stale period is 7 days.

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await CacheSystem().init(stalePeriod: const Duration(days: 7));
  runApp(const MyApp());
}

To cache files from the internet, use the CacheSystem().getFile() function. This function takes the url of the file to be cached as the parameter. Url type must Uri. It returns a Future which will return the path of the cached file. The cached file will be deleted after the stale period.

Future<XFile?> cacheFile() async {
  final String url = 'https://www.example.com/image.png';
  final XFile? file = CacheSystem().getFile(Uri.parse(
                'https://fastly.picsum.photos/id/91/1500/1500.jpg?hmac=gFLcWG7TwMqsOm5ZizQJNJ2tYsENkSQdMMmNNp8Avvs'));
    return file;
}

or if your file is an image and you want to render it in the UI, you can use the FutureBuilder widget to render the image.

FutureBuilder(
      future: CacheSystem().getFile(Uri.parse(
          'https://fastly.picsum.photos/id/91/1500/1500.jpg?hmac=gFLcWG7TwMqsOm5ZizQJNJ2tYsENkSQdMMmNNp8Avvs')),
      builder: (context, snapshot) {
        if (snapshot.hasData) {
          return Image.file(File(snapshot.data!.path));
        }
        return const SizedBox();
      },
    );

If you want get all the cached files, you can use the CacheSystem().getAllFiles() function. This function returns a Future which will return a list of all the cached files.

Future<List<XFile?>> getAllFiles() async {
  final List<XFile> files = await CacheSystem().getAllFiles();
  return files;
}

or if you want to render all the cached file in the UI, you can use like this.

GridView.builder(
      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 3,
      ),
      itemCount: files.length,
      itemBuilder: (context, index) {
        final file = files[index];
        if (file?.mimeType != null &&
            file?.mimeType?.contains('image') == true) {
          return Padding(
            padding: const EdgeInsets.all(8.0),
            child: Image.file(
              File(file!.path),
              height: 100,
              width: 100,
            ),
          );
        } else {
          return Padding(
            padding: const EdgeInsets.all(8.0),
            child: Container(
              height: 100,
              width: 100,
              color: Colors.grey,
              child: Text(
                file?.mimeType ?? 'Unknown',
                textAlign: TextAlign.center,
              ),
            ),
          );
        }
      },
    );