| // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| /** Transfomer that combines multiple dart script tags into a single one. */ |
| library polymer.src.build.script_compactor; |
| |
| import 'dart:async'; |
| |
| import 'package:barback/barback.dart'; |
| import 'package:html5lib/parser.dart' show parseFragment; |
| import 'package:path/path.dart' as path; |
| |
| import 'code_extractor.dart'; // import just for documentation. |
| import 'common.dart'; |
| |
| /** |
| * Combines Dart script tags into a single script tag, and creates a new Dart |
| * file that calls the main function of each of the original script tags. |
| * |
| * This transformer assumes that all script tags point to external files. To |
| * support script tags with inlined code, use this transformer after running |
| * [InlineCodeExtractor] on an earlier phase. |
| * |
| * Internally, this transformer will convert each script tag into an import |
| * statement to a library, and then uses `initPolymer` (see polymer.dart) to |
| * invoke the main method on each of these libraries and register any polymer |
| * elements annotated with `@CustomTag`. |
| */ |
| class ScriptCompactor extends Transformer with PolymerTransformer { |
| final TransformOptions options; |
| |
| ScriptCompactor(this.options); |
| |
| /** Only run on entry point .html files. */ |
| Future<bool> isPrimary(Asset input) => |
| new Future.value(options.isHtmlEntryPoint(input.id)); |
| |
| Future apply(Transform transform) { |
| var id = transform.primaryInput.id; |
| var logger = transform.logger; |
| return readPrimaryAsHtml(transform).then((document) { |
| var libraries = []; |
| bool changed = false; |
| var dartLoaderTag = null; |
| for (var tag in document.queryAll('script')) { |
| var src = tag.attributes['src']; |
| if (src != null) { |
| if (src == 'packages/polymer/boot.js') { |
| tag.remove(); |
| continue; |
| } |
| var last = src.split('/').last; |
| if (last == 'dart.js') { |
| dartLoaderTag = tag; |
| } |
| } |
| if (tag.attributes['type'] != 'application/dart') continue; |
| tag.remove(); |
| changed = true; |
| if (src == null) { |
| logger.warning('unexpected script without a src url. The ' |
| 'ScriptCompactor transformer should run after running the ' |
| 'InlineCodeExtractor', tag.sourceSpan); |
| continue; |
| } |
| var libraryId = resolve(id, src, logger, tag.sourceSpan); |
| |
| // TODO(sigmund): should we detect/remove duplicates? |
| if (libraryId == null) continue; |
| libraries.add(libraryId); |
| } |
| |
| if (!changed) { |
| transform.addOutput(transform.primaryInput); |
| return; |
| } |
| |
| var bootstrapId = id.addExtension('_bootstrap.dart'); |
| var filename = path.url.basename(bootstrapId.path); |
| |
| var bootstrapScript = parseFragment( |
| '<script type="application/dart" src="$filename"></script>'); |
| if (dartLoaderTag == null) { |
| document.body.nodes.add(bootstrapScript); |
| document.body.nodes.add(parseFragment( |
| '<script src="packages/browser/dart.js"></script>')); |
| } else if (dartLoaderTag.parent != document.body) { |
| document.body.nodes.add(bootstrapScript); |
| } else { |
| document.body.insertBefore(bootstrapScript, dartLoaderTag); |
| } |
| |
| var urls = libraries.map((id) => assetUrlFor(id, bootstrapId, logger)) |
| .where((url) => url != null).toList(); |
| var buffer = new StringBuffer()..write(_header); |
| for (int i = 0; i < urls.length; i++) { |
| buffer.writeln("import '${urls[i]}' as i$i;"); |
| } |
| buffer..write(_mainPrefix) |
| ..writeAll(urls.map((url) => " '$url',\n")) |
| ..write(_mainSuffix); |
| |
| transform.addOutput(new Asset.fromString(bootstrapId, buffer.toString())); |
| transform.addOutput(new Asset.fromString(id, document.outerHtml)); |
| }); |
| } |
| } |
| |
| const _header = """ |
| library app_bootstrap; |
| |
| import 'package:polymer/polymer.dart'; |
| import 'dart:mirrors' show currentMirrorSystem; |
| |
| """; |
| |
| const _mainPrefix = """ |
| |
| void main() { |
| initPolymer([ |
| """; |
| |
| // TODO(sigmund): investigate alternative to get the baseUri (dartbug.com/12612) |
| const _mainSuffix = """ |
| ], currentMirrorSystem().isolate.rootLibrary.uri.toString()); |
| } |
| """; |