// 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 '../base/utils.dart'; import '../build_info.dart'; import '../features.dart'; import '../globals.dart' as globals; import '../html_utils.dart'; import '../project.dart'; import '../runner/flutter_command.dart' show DevelopmentArtifact, FlutterCommandResult, FlutterOptions; import '../web/compile.dart'; import '../web/file_generators/flutter_service_worker_js.dart'; import '../web/web_constants.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(); addEnableExperimentation(hide: !verboseHelp); addNullSafetyModeOptions(hide: !verboseHelp); addNativeNullAssertions(); // // Flutter web-specific options // argParser.addSeparator('Flutter web options'); 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( 'pwa-strategy', defaultsTo: ServiceWorkerStrategy.offlineFirst.cliName, help: 'The caching strategy to be used by the PWA service worker.', allowed: ServiceWorkerStrategy.values.map((ServiceWorkerStrategy e) => e.cliName), allowedHelp: CliEnum.allowedHelp(ServiceWorkerStrategy.values), ); usesWebRendererOption(); usesWebResourcesCdnFlag(); // // JavaScript compilation options // argParser.addSeparator('JavaScript compilation options'); 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.addOption('dart2js-optimization', help: 'Sets the optimization level used for Dart compilation to JavaScript. ' 'Valid values range from O1 to O4.', defaultsTo: JsCompilerConfig.kDart2jsDefaultOptimizationLevel, allowed: const <String>['O1', 'O2', 'O3', '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.' ); // // Experimental options // if (featureFlags.isFlutterWebWasmEnabled) { argParser.addSeparator('Experimental options'); } argParser.addFlag( FlutterOptions.kWebWasmFlag, help: 'Compile to WebAssembly rather than JavaScript.\n$kWasmMoreInfo', negatable: false, hide: !featureFlags.isFlutterWebWasmEnabled, ); argParser.addFlag( 'omit-type-checks', help: 'Omit type checks in Wasm output.\n' 'Reduces code size and improves performance, but may affect runtime correctness. Use with care.', negatable: false, hide: !featureFlags.isFlutterWebWasmEnabled, ); argParser.addOption( 'wasm-opt', help: 'Optimize output wasm using the Binaryen (https://github.com/WebAssembly/binaryen) tool.', defaultsTo: WasmOptLevel.defaultValue.cliName, allowed: WasmOptLevel.values.map<String>((WasmOptLevel e) => e.cliName), allowedHelp: CliEnum.allowedHelp(WasmOptLevel.values), hide: !featureFlags.isFlutterWebWasmEnabled, ); } 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 WebCompilerConfig compilerConfig; if (boolArg('wasm')) { if (!featureFlags.isFlutterWebWasmEnabled) { throwToolExit('Compiling to WebAssembly (wasm) is only available on the master channel.'); } compilerConfig = WasmCompilerConfig( omitTypeChecks: boolArg('omit-type-checks'), wasmOpt: WasmOptLevel.values.byName(stringArg('wasm-opt')!), ); } else { compilerConfig = JsCompilerConfig( csp: boolArg('csp'), optimizationLevel: stringArg('dart2js-optimization') ?? JsCompilerConfig.kDart2jsDefaultOptimizationLevel, dumpInfo: boolArg('dump-info'), nativeNullAssertions: boolArg('native-null-assertions'), noFrequencyBasedMinification: boolArg('no-frequency-based-minification'), sourceMaps: boolArg('source-maps'), ); } final FlutterProject flutterProject = FlutterProject.current(); final String target = stringArg('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 = stringArg('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. " 'Please add `<base href="$kBaseHrefPlaceholder">` 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); final WebBuilder webBuilder = WebBuilder( logger: globals.logger, processManager: globals.processManager, buildSystem: globals.buildSystem, fileSystem: globals.fs, flutterVersion: globals.flutterVersion, usage: globals.flutterUsage, analytics: globals.analytics, ); await webBuilder.buildWeb( flutterProject, target, buildInfo, ServiceWorkerStrategy.fromCliName(stringArg('pwa-strategy')), compilerConfig: compilerConfig, baseHref: baseHref, outputDirectoryPath: outputDirectoryPath, ); return FlutterCommandResult.success(); } }