// Copyright 2014 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. import '../base/common.dart'; import '../base/file_system.dart'; import '../build_info.dart'; import '../build_system/targets/web.dart'; import '../features.dart'; import '../project.dart'; import '../runner/flutter_command.dart' show DevelopmentArtifact, FlutterCommandResult; import '../web/compile.dart'; import 'build.dart'; class BuildWebCommand extends BuildSubCommand { BuildWebCommand({ required super.logger, required FileSystem fileSystem, required bool verboseHelp, }) : _fileSystem = fileSystem, super(verboseHelp: verboseHelp) { addTreeShakeIconsFlag(); usesTargetOption(); usesOutputDir(); usesPubOption(); usesBuildNumberOption(); usesBuildNameOption(); addBuildModeFlags(verboseHelp: verboseHelp, excludeDebug: true); usesDartDefineOption(); usesWebRendererOption(); addEnableExperimentation(hide: !verboseHelp); addNullSafetyModeOptions(hide: !verboseHelp); addNativeNullAssertions(); argParser.addFlag('csp', negatable: false, help: 'Disable dynamic generation of code in the generated output. ' 'This is necessary to satisfy CSP restrictions (see http://www.w3.org/TR/CSP/).' ); argParser.addFlag( 'source-maps', help: 'Generate a sourcemap file. These can be used by browsers ' 'to view and debug the original source code of a compiled and minified Dart ' 'application.' ); argParser.addFlag( 'wasm', help: 'Compile to WebAssembly rather than Javascript (experimental).' ); argParser.addOption('pwa-strategy', defaultsTo: kOfflineFirst, help: 'The caching strategy to be used by the PWA service worker.', allowed: <String>[ kOfflineFirst, kNoneWorker, ], allowedHelp: <String, String>{ kOfflineFirst: 'Attempt to cache the application shell eagerly and ' 'then lazily cache all subsequent assets as they are loaded. When ' 'making a network request for an asset, the offline cache will be ' 'preferred.', kNoneWorker: 'Generate a service worker with no body. This is useful for ' 'local testing or in cases where the service worker caching functionality ' 'is not desirable', }, ); argParser.addOption('base-href', help: 'Overrides the href attribute of the <base> tag in web/index.html. ' 'No change is done to web/index.html file if this flag is not provided. ' 'The value has to start and end with a slash "/". ' 'For more information: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base' ); argParser.addOption('dart2js-optimization', help: 'Sets the optimization level used for Dart compilation to JavaScript. ' 'Valid values range from O0 to O4.' ); argParser.addFlag('dump-info', negatable: false, help: 'Passes "--dump-info" to the Javascript compiler which generates ' 'information about the generated code is a .js.info.json file.' ); argParser.addFlag('no-frequency-based-minification', negatable: false, help: 'Disables the frequency based minifier. ' 'Useful for comparing the output between builds.' ); } final FileSystem _fileSystem; @override Future<Set<DevelopmentArtifact>> get requiredArtifacts async => const <DevelopmentArtifact>{ DevelopmentArtifact.web, }; @override final String name = 'web'; @override bool get hidden => !featureFlags.isWebEnabled; @override final String description = 'Build a web application bundle.'; @override Future<FlutterCommandResult> runCommand() async { if (!featureFlags.isWebEnabled) { throwToolExit('"build web" is not currently supported. To enable, run "flutter config --enable-web".'); } final FlutterProject flutterProject = FlutterProject.current(); final String target = stringArgDeprecated('target')!; final BuildInfo buildInfo = await getBuildInfo(); if (buildInfo.isDebug) { throwToolExit('debug builds cannot be built directly for the web. Try using "flutter run"'); } final String? baseHref = stringArgDeprecated('base-href'); if (baseHref != null && !(baseHref.startsWith('/') && baseHref.endsWith('/'))) { throwToolExit('base-href should start and end with /'); } if (!flutterProject.web.existsSync()) { throwToolExit('Missing index.html.'); } if (!_fileSystem.currentDirectory .childDirectory('web') .childFile('index.html') .readAsStringSync() .contains(kBaseHrefPlaceholder) && baseHref != null) { throwToolExit( "Couldn't find the placeholder for base href. " r'Please add `<base href="$FLUTTER_BASE_HREF">` to web/index.html' ); } // Currently supporting options [output-dir] and [output] as // valid approaches for setting output directory of build artifacts final String? outputDirectoryPath = stringArg('output'); displayNullSafetyMode(buildInfo); await buildWeb( flutterProject, target, buildInfo, boolArgDeprecated('csp'), stringArgDeprecated('pwa-strategy')!, boolArgDeprecated('source-maps'), boolArgDeprecated('native-null-assertions'), boolArgDeprecated('wasm'), baseHref: baseHref, dart2jsOptimization: stringArgDeprecated('dart2js-optimization'), outputDirectoryPath: outputDirectoryPath, dumpInfo: boolArgDeprecated('dump-info'), noFrequencyBasedMinification: boolArgDeprecated('no-frequency-based-minification'), ); return FlutterCommandResult.success(); } }