✨ Flavored assets (#530)

## What does this change?

Resolves #494 🎯

Generated assets would contain the flavor info specified in the `pubspec.yaml`, but only as a constant not involved with actual flavoring.

## Type of change

- [x] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [x] This change requires a documentation update

README.md

@@ -167,6 +167,18 @@ flutter:
 
 These configurations will generate **`assets.gen.dart`** under the **`lib/gen/`** directory by default.
 
+#### Flavored assets
+
+Flutter supports
+[Conditionally bundling assets based on flavor](https://docs.flutter.dev/deployment/flavors#conditionally-bundling-assets-based-on-flavor).
+Assets are only available with flavors if specified.
+`flutter_gen` will generate the specified `flavors` for assets regardless the current flavor.
+The `flavors` field accessible though `.flavors`, for example:
+
+```dart
+print(MyAssets.images.chip4.flavors); // -> {'extern'}
+```
+
 #### Excluding generating for assets
 
 You can specify `flutter_gen > assets > exclude` using `Glob` patterns to exclude particular assets.

examples/example/lib/gen/assets.gen.dart

@@ -35,6 +35,9 @@ class $AssetsImagesGen {
  /// File path: assets/images/chip2.jpg
  AssetGenImage get chip2 => const AssetGenImage('assets/images/chip2.jpg');
 
+ /// Directory path: assets/images/chip3
+ $AssetsImagesChip3Gen get chip3 => const $AssetsImagesChip3Gen();
+
  /// Directory path: assets/images/chip4
  $AssetsImagesChip4Gen get chip4 => const $AssetsImagesChip4Gen();
 
@@ -142,12 +145,25 @@ class $AssetsUnknownGen {
  List<String> get values => [changelog, readme, unknownMimeType];
 }
 
+class $AssetsImagesChip3Gen {
+ const $AssetsImagesChip3Gen();
+
+ /// File path: assets/images/chip3/chip3.jpg
+ AssetGenImage get chip3 =>
+ const AssetGenImage('assets/images/chip3/chip3.jpg');
+
+ /// List of all assets
+ List<AssetGenImage> get values => [chip3];
+}
+
 class $AssetsImagesChip4Gen {
  const $AssetsImagesChip4Gen();
 
  /// File path: assets/images/chip4/chip4.jpg
- AssetGenImage get chip4 =>
- const AssetGenImage('assets/images/chip4/chip4.jpg');
+ AssetGenImage get chip4 => const AssetGenImage(
+ 'assets/images/chip4/chip4.jpg',
+ flavors: {'extern'},
+ );
 
  /// List of all assets
  List<AssetGenImage> get values => [chip4];
@@ -202,11 +218,16 @@ class MyAssets {
 }
 
 class AssetGenImage {
- const AssetGenImage(this._assetName, {this.size = null});
+ const AssetGenImage(
+ this._assetName, {
+ this.size,
+ this.flavors = const {},
+ });
 
  final String _assetName;
 
  final Size? size;
+ final Set<String> flavors;
 
  Image image({
  Key? key,
@@ -280,17 +301,19 @@ class AssetGenImage {
 class SvgGenImage {
  const SvgGenImage(
  this._assetName, {
- this.size = null,
+ this.size,
+ this.flavors = const {},
  }) : _isVecFormat = false;
 
  const SvgGenImage.vec(
  this._assetName, {
- this.size = null,
+ this.size,
+ this.flavors = const {},
  }) : _isVecFormat = true;
 
  final String _assetName;
-
  final Size? size;
+ final Set<String> flavors;
  final bool _isVecFormat;
 
  SvgPicture svg({
@@ -313,12 +336,23 @@ class SvgGenImage {
  @deprecated BlendMode colorBlendMode = BlendMode.srcIn,
  @deprecated bool cacheColorFilter = false,
  }) {
+ final BytesLoader loader;
+ if (_isVecFormat) {
+ loader = AssetBytesLoader(
+ _assetName,
+ assetBundle: bundle,
+ packageName: package,
+ );
+ } else {
+ loader = SvgAssetLoader(
+ _assetName,
+ assetBundle: bundle,
+ packageName: package,
+ theme: theme,
+ );
+ }
  return SvgPicture(
- _isVecFormat
- ? AssetBytesLoader(_assetName,
- assetBundle: bundle, packageName: package)
- : SvgAssetLoader(_assetName,
- assetBundle: bundle, packageName: package, theme: theme),
+ loader,
  key: key,
  matchTextDirection: matchTextDirection,
  width: width,
@@ -342,9 +376,13 @@ class SvgGenImage {
 }
 
 class FlareGenImage {
- const FlareGenImage(this._assetName);
+ const FlareGenImage(
+ this._assetName, {
+ this.flavors = const {},
+ });
 
  final String _assetName;
+ final Set<String> flavors;
 
  FlareActor flare({
  String? boundsNode,
@@ -385,9 +423,13 @@ class FlareGenImage {
 }
 
 class RiveGenImage {
- const RiveGenImage(this._assetName);
+ const RiveGenImage(
+ this._assetName, {
+ this.flavors = const {},
+ });
 
  final String _assetName;
+ final Set<String> flavors;
 
  RiveAnimation rive({
  String? artboard,
@@ -422,9 +464,13 @@ class RiveGenImage {
 }
 
 class LottieGenImage {
- const LottieGenImage(this._assetName);
+ const LottieGenImage(
+ this._assetName, {
+ this.flavors = const {},
+ });
 
  final String _assetName;
+ final Set<String> flavors;
 
  LottieBuilder lottie({
  Animation<double>? controller,

examples/example/pubspec.yaml

@@ -51,7 +51,6 @@ flutter_gen:
  style: dot-delimiter
 
  exclude:
- - assets/images/chip3/chip3.jpg
  - assets-extern/*
  - pictures/chip5.jpg
 
@@ -76,7 +75,6 @@ flutter:
  - assets/images/
  - assets/images/chip3/chip3.jpg
  - assets/images/chip3/chip3.jpg # duplicated
- - assets/images/chip4/
  - assets/images/icons/fuchsia.svg
  - assets/images/icons/kmm.svg
  - assets/images/icons/paint.svg
@@ -91,6 +89,10 @@ flutter:
  - assets/mix/
  - assets-extern/
  - pictures/chip5.jpg
+
+ - path: assets/images/chip4/chip4.jpg
+ flavors:
+ - extern
  fonts:
  - family: Raleway
  fonts:

packages/core/lib/generators/assets_generator.dart

@@ -13,11 +13,13 @@ import 'package:flutter_gen_core/generators/integrations/rive_integration.dart';
 import 'package:flutter_gen_core/generators/integrations/svg_integration.dart';
 import 'package:flutter_gen_core/settings/asset_type.dart';
 import 'package:flutter_gen_core/settings/config.dart';
+import 'package:flutter_gen_core/settings/flavored_asset.dart';
 import 'package:flutter_gen_core/settings/pubspec.dart';
 import 'package:flutter_gen_core/utils/error.dart';
 import 'package:flutter_gen_core/utils/string.dart';
 import 'package:glob/glob.dart';
 import 'package:path/path.dart';
+import 'package:yaml/yaml.dart';
 
 class AssetsGenConfig {
  AssetsGenConfig._(
@@ -41,7 +43,7 @@ class AssetsGenConfig {
  final String rootPath;
  final String _packageName;
  final FlutterGen flutterGen;
- final List<String> assets;
+ final List<Object> assets;
  final List<Glob> exclude;
 
  String get packageParameterLiteral =>
@@ -194,51 +196,89 @@ String? generatePackageNameForConfig(AssetsGenConfig config) {
  }
 }
 
-/// Returns a list of all releative path assets that are to be considered.
-List<String> _getAssetRelativePathList(
+/// Returns a list of all relative path assets that are to be considered.
+List<FlavoredAsset> _getAssetRelativePathList(
  /// The absolute root path of the assets directory.
  String rootPath,
 
- /// List of assets as provided the `flutter`.`assets` section in the pubspec.yaml.
- List<String> assets,
+ /// List of assets as provided the `flutter -> assets`
+ /// section in the pubspec.yaml.
+ List<Object> assets,
 
- /// List of globs as provided the `flutter_gen`.`assets`.`exclude` section in the pubspec.yaml.
+ /// List of globs as provided the `flutter_gen -> assets -> exclude`
+ /// section in the pubspec.yaml.
  List<Glob> excludes,
 ) {
- final assetRelativePathList = <String>[];
- for (final assetName in assets) {
- final assetAbsolutePath = join(rootPath, assetName);
+ // Normalize.
+ final normalizedAssets = <Object>{...assets.whereType<String>()};
+ final normalizingMap = <String, Set<String>>{};
+ // Resolve flavored assets.
+ for (final map in assets.whereType<YamlMap>()) {
+ final path = (map['path'] as String).trim();
+ final flavors =
+ (map['flavors'] as YamlList?)?.toSet().cast<String>() ?? <String>{};
+ if (normalizingMap.containsKey(path)) {
+ // https://github.com/flutter/flutter/blob/5187cab7bdd434ca74abb45895d17e9fa553678a/packages/flutter_tools/lib/src/asset.dart#L1137-L1139
+ throw StateError(
+ 'Multiple assets entries include the file "$path", '
+ 'but they specify different lists of flavors.',
+ );
+ }
+ normalizingMap[path] = flavors;
+ }
+ for (final entry in normalizingMap.entries) {
+ normalizedAssets.add(
+ YamlMap.wrap({'path': entry.key, 'flavors': entry.value}),
+ );
+ }
+
+ final assetRelativePathList = <FlavoredAsset>[];
+ for (final asset in normalizedAssets) {
+ final FlavoredAsset tempAsset;
+ if (asset is YamlMap) {
+ tempAsset = FlavoredAsset(path: asset['path'], flavors: asset['flavors']);
+ } else {
+ tempAsset = FlavoredAsset(path: (asset as String).trim());
+ }
+ final assetAbsolutePath = join(rootPath, tempAsset.path);
  if (FileSystemEntity.isDirectorySync(assetAbsolutePath)) {
  assetRelativePathList.addAll(Directory(assetAbsolutePath)
  .listSync()
  .whereType<File>()
- .map((e) => relative(e.path, from: rootPath))
+ .map(
+ (e) => tempAsset.copyWith(path: relative(e.path, from: rootPath)),
+ )
  .toList());
  } else if (FileSystemEntity.isFileSync(assetAbsolutePath)) {
- assetRelativePathList.add(relative(assetAbsolutePath, from: rootPath));
+ assetRelativePathList.add(
+ tempAsset.copyWith(path: relative(assetAbsolutePath, from: rootPath)),
+ );
  }
  }
 
  if (excludes.isEmpty) {
  return assetRelativePathList;
  }
-
  return assetRelativePathList
- .where((file) => !excludes.any((exclude) => exclude.matches(file)))
+ .where((asset) => !excludes.any((exclude) => exclude.matches(asset.path)))
  .toList();
 }
 
 AssetType _constructAssetTree(
- List<String> assetRelativePathList, String rootPath) {
+ List<FlavoredAsset> assetRelativePathList,
+ String rootPath,
+) {
  // Relative path is the key
  final assetTypeMap = <String, AssetType>{
- '.': AssetType(rootPath: rootPath, path: '.'),
+ '.': AssetType(rootPath: rootPath, path: '.', flavors: {}),
  };
- for (final assetPath in assetRelativePathList) {
- var path = assetPath;
+ for (final asset in assetRelativePathList) {
+ String path = asset.path;
  while (path != '.') {
  assetTypeMap.putIfAbsent(
- path, () => AssetType(rootPath: rootPath, path: path));
+ path,
+ () => AssetType(rootPath: rootPath, path: path, flavors: asset.flavors),
+ );
  path = dirname(path);
  }
  }
@@ -320,7 +360,8 @@ String _dotDelimiterStyleDefinition(
  final assetsStaticStatements = <_Statement>[];
 
  final assetTypeQueue = ListQueue<AssetType>.from(
- _constructAssetTree(assetRelativePathList, rootPath).children);
+ _constructAssetTree(assetRelativePathList, rootPath).children,
+ );
 
  while (assetTypeQueue.isNotEmpty) {
  final assetType = assetTypeQueue.removeFirst();
@@ -428,14 +469,20 @@ String _flatStyleDefinition(
  List<Integration> integrations,
  String Function(String) style,
 ) {
- final statements = _getAssetRelativePathList(
+ final List<FlavoredAsset> paths = _getAssetRelativePathList(
  config.rootPath,
  config.assets,
  config.exclude,
- )
- .distinct()
- .sorted()
- .map((assetPath) => AssetType(rootPath: config.rootPath, path: assetPath))
+ );
+ paths.sort(((a, b) => a.path.compareTo(b.path)));
+ final statements = paths
+ .map(
+ (assetPath) => AssetType(
+ rootPath: config.rootPath,
+ path: assetPath.path,
+ flavors: assetPath.flavors,
+ ),
+ )
  .mapToUniqueAssetType(style)
  .map(
  (e) => _createAssetTypeStatement(

packages/core/lib/generators/integrations/flare_integration.dart

@@ -17,9 +17,14 @@ class FlareIntegration extends Integration {
  String get classOutput => _classDefinition;
 
  String get _classDefinition => '''class FlareGenImage {
- const FlareGenImage(this._assetName);
+ const FlareGenImage(
+ this._assetName, {
+ this.flavors = const {},
+ });
 
  final String _assetName;
+ final Set<String> flavors;
+
 ${isPackage ? "\n static const String package = '$packageName';" : ''}
 
  FlareActor flare({
@@ -63,10 +68,6 @@ ${isPackage ? "\n static const String package = '$packageName';" : ''}
  @override
  String get className => 'FlareGenImage';
 
- @override
- String classInstantiate(AssetType asset) =>
- 'FlareGenImage(\'${asset.posixStylePath}\')';
-
  @override
  bool isSupport(AssetType asset) => asset.extension == '.flr';