erf/asset_cache

asset_cache

asset_cache will load and cache any asset of type T given a decoder.

It was made as CachingAssetBundle does not cache binary data.

Binary resources (from load) are not cached.

Usage

Describe assets in your pubspec.yaml:

  assets:
     - assets/images/
     - assets/json/

Create asset cache instances with an optional basePath to avoid full paths:

final imageCache = ImageAssetCache(basePath: "assets/images/");
final jsonCache = JsonAssetCache(basePath: "assets/json/");

Load and cache assets using load returns a Future<T>:

final image = await imageCache.load('sprite.png')
final json = await jsonCache.load('sprite.json')

Asset Decoders

The following AssetCache implementations are included:

• ImageAssetCache
• JsonAssetCache
• TextAssetCache
• ByteDataAssetCache

Custom AssetCache

Create a custom asset cache by inheriting from AssetCache and pass it a AssetDecoder.

You can also inherit from GenericCache and override loadAsset, if you don't want to load from a AssetBundle.

Cache Management

The cache provides several management methods:

// Load and cache an asset (returns cached version if already loaded)
final image = await imageCache.load('sprite.png');

// Check if an asset is cached
if (imageCache.contains('sprite.png')) {
  // Asset is already cached
}

// Get the number of cached items
print('Cached items: ${imageCache.size}');

// Remove a specific cached item
imageCache.remove('sprite.png');

// Clear all cached items
imageCache.clear();

Preloading Assets

For better performance, you can preload multiple assets concurrently:

// Preload multiple assets at once
await imageCache.preload(['sprite1.png', 'sprite2.png', 'sprite3.png']);

// Remember to call this before preloading at app startup
WidgetsFlutterBinding.ensureInitialized();

Exception Handling

The package includes custom exceptions for better error handling:

• AssetNotFoundException - Thrown when an asset cannot be found or loaded
• DecodingException - Thrown when an asset cannot be decoded to the expected type
• PreLoadingAssetsNotFoundException - Thrown when preloading fails for some assets

try {
  final image = await imageCache.load('missing.png');
} on AssetNotFoundException catch (e) {
  print('Asset not found: ${e.assetKey}');
} on DecodingException catch (e) {
  print('Failed to decode asset: ${e.assetKey}');
}

More

See example and test.