Index: lib/src/mirror_initializer.dart |
diff --git a/lib/src/mirror_initializer.dart b/lib/src/mirror_initializer.dart |
new file mode 100644 |
index 0000000000000000000000000000000000000000..ff25ad89ff400d8b7182799a49b3020982e437fe |
--- /dev/null |
+++ b/lib/src/mirror_initializer.dart |
@@ -0,0 +1,145 @@ |
+// Copyright (c) 2014, 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. |
+ |
+/// Contains logic to initialize web_components apps during development. This |
+/// implementation uses dart:mirrors to load each library as they are discovered |
+/// through HTML imports. This is only meant to be used during development in |
+/// dartium, and the web_components transformers replace this implementation |
+/// for deployment. |
+library web_components.src.mirror_initializer; |
+ |
+import 'dart:async'; |
+import 'dart:collection' show LinkedHashMap; |
+import 'dart:mirrors'; |
+import 'dart:html'; |
+import 'package:initialize/initialize.dart' as init; |
+ |
+Future run({List<Type> typeFilter, init.InitializerFilter customFilter}) async { |
+ var libraryUris = _discoverLibrariesToLoad(document, window.location.href) |
+ .map(Uri.parse); |
+ |
+ for (var uri in libraryUris) { |
+ await init.run( |
+ typeFilter: typeFilter, customFilter: customFilter, from: uri); |
+ } |
+ return null; |
+} |
+ |
+/// Walks the HTML import structure to discover all script tags that are |
+/// implicitly loaded. This code is only used in Dartium and should only be |
+/// called after all HTML imports are resolved. Polymer ensures this by asking |
+/// users to put their Dart script tags after all HTML imports (this is checked |
+/// by the linter, and Dartium will otherwise show an error message). |
+Iterable<_ScriptInfo> _discoverScripts( |
+ Document doc, String baseUri, [_State state]) { |
+ if (state == null) state = new _State(); |
+ if (doc == null) { |
+ print('warning: $baseUri not found.'); |
+ return state.scripts.values; |
+ } |
+ if (!state.seen.add(doc)) return state.scripts.values; |
+ |
+ for (var node in doc.querySelectorAll('script,link[rel="import"]')) { |
+ if (node is LinkElement) { |
+ _discoverScripts(node.import, node.href, state); |
+ } else if (node is ScriptElement && node.type == 'application/dart') { |
+ var info = _scriptInfoFor(node, baseUri); |
+ if (state.scripts.containsKey(info.resolvedUrl)) { |
+ print('warning: Script `${info.resolvedUrl}` included more than once. ' |
+ 'See http://goo.gl/5HPeuP#polymer_44 for more details.'); |
Siggi Cherem (dart-lang)
2015/03/23 22:16:26
we might want to relabel this warning in the futur
jakemac
2015/03/23 22:32:41
Acknowledged.
|
+ } else { |
+ state.scripts[info.resolvedUrl] = info; |
+ } |
+ } |
+ } |
+ return state.scripts.values; |
+} |
+ |
+/// Internal state used in [_discoverScripts]. |
+class _State { |
+ /// Documents that we have visited thus far. |
+ final Set<Document> seen = new Set(); |
+ |
+ /// Scripts that have been discovered, in tree order. |
+ final LinkedHashMap<String, _ScriptInfo> scripts = {}; |
+} |
+ |
+/// Holds information about a Dart script tag. |
+class _ScriptInfo { |
+ /// The original URL seen in the tag fully resolved. |
+ final String resolvedUrl; |
+ |
+ /// Whether there was no URL, but code inlined instead. |
+ bool get isInline => text != null; |
+ |
+ /// Whether it seems to be a 'package:' URL (starts with the package-root). |
+ bool get isPackage => packageUrl != null; |
+ |
+ /// The equivalent 'package:' URL, if any. |
+ final String packageUrl; |
+ |
+ /// The inlined text, if any. |
+ final String text; |
+ |
+ /// Returns a base64 `data:` uri with the contents of [text]. |
+ // TODO(sigmund): change back to application/dart: using text/javascript seems |
+ // wrong but it hides a warning in Dartium (dartbug.com/18000). |
+ String get dataUrl => 'data:text/javascript;base64,${window.btoa(text)}'; |
+ |
+ /// URL to import the contents of the original script from Dart. This is |
+ /// either the source URL if the script tag had a `src` attribute, or a base64 |
+ /// encoded `data:` URL if the script contents are inlined, or a `package:` |
+ /// URL if the script can be resolved via a package URL. |
+ String get importUrl => |
+ isInline ? dataUrl : (isPackage ? packageUrl : resolvedUrl); |
+ |
+ _ScriptInfo(this.resolvedUrl, {this.packageUrl, this.text}); |
+} |
+ |
+ |
+// TODO(sigmund): explore other (cheaper) ways to resolve URIs relative to the |
+// root library (see dartbug.com/12612) |
+final _rootUri = currentMirrorSystem().isolate.rootLibrary.uri; |
+ |
+/// Returns [_ScriptInfo] for [script] which was seen in [baseUri]. |
+_ScriptInfo _scriptInfoFor(script, baseUri) { |
+ var uriString = script.src; |
+ if (uriString != '') { |
+ var uri = _rootUri.resolve(uriString); |
+ if (!_isHttpStylePackageUrl(uri)) return new _ScriptInfo('$uri'); |
+ // Use package: urls if available. This rule here is more permissive than |
+ // how we translate urls in polymer-build, but we expect Dartium to limit |
+ // the cases where there are differences. The polymer-build issues an error |
+ // when using packages/ inside lib without properly stepping out all the way |
+ // to the packages folder. If users don't create symlinks in the source |
+ // tree, then Dartium will also complain because it won't find the file seen |
+ // in an HTML import. |
+ var packagePath = uri.path.substring( |
+ uri.path.lastIndexOf('packages/') + 'packages/'.length); |
+ return new _ScriptInfo('$uri', packageUrl: 'package:$packagePath'); |
+ } |
+ |
+ return new _ScriptInfo(baseUri, text: script.text); |
+} |
+ |
+/// Whether [uri] is an http URI that contains a 'packages' segment, and |
+/// therefore could be converted into a 'package:' URI. |
+bool _isHttpStylePackageUrl(Uri uri) { |
+ var uriPath = uri.path; |
+ return uri.scheme == _rootUri.scheme && |
+ // Don't process cross-domain uris. |
+ uri.authority == _rootUri.authority && |
+ uriPath.endsWith('.dart') && |
+ (uriPath.contains('/packages/') || uriPath.startsWith('packages/')); |
+} |
+ |
+Iterable<String> _discoverLibrariesToLoad(Document doc, String baseUri) => |
+ _discoverScripts(doc, baseUri).map( |
+ (info) => _packageUrlExists(info) ? info.packageUrl : info.resolvedUrl); |
Siggi Cherem (dart-lang)
2015/03/23 22:16:26
I think that to support inline Dart script tags, w
jakemac
2015/03/23 22:32:41
worked on this together, and stripped out some mor
|
+ |
+/// All libraries in the current isolate. |
+final _libs = currentMirrorSystem().libraries; |
+ |
+bool _packageUrlExists(_ScriptInfo info) => |
+ info.isPackage && _libs[Uri.parse(info.packageUrl)] != null; |