Bring back initPolymer, allow boot.js only if using "polymer_experimental.html".

pkg/polymer/lib/src/mirror_loader.dart

 // 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 polymer 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 during development in
 /// dartium, and the polymer transformers replace this implementation with
 /// codege generation in the polymer-build steps.
 library polymer.src.mirror_loader;
 
 import 'dart:async';
 import 'dart:html';
 import 'dart:collection' show LinkedHashMap;
 
 // Technically, we shouldn't need any @MirrorsUsed, since this is for
 // development only, but our test bots don't yet run pub-build. See more details
 // on the comments of the mirrors import in `lib/polymer.dart`.
 @MirrorsUsed(metaTargets:
     const [CustomTag, InitMethodAnnotation],
     override: const ['smoke.mirrors', 'polymer.src.mirror_loader'])
 import 'dart:mirrors';
 
 import 'package:logging/logging.dart' show Logger;
+import 'package:observe/src/dirty_check.dart';
 import 'package:polymer/polymer.dart';
-import 'package:observe/src/dirty_check.dart';
 
 
+/// Used by code generated from the experimental polymer bootstrap in boot.js.
 void startPolymerInDevelopment(List<String> librariesToLoad) {
   dirtyCheckZone()..run(() {
     startPolymer(discoverInitializers(librariesToLoad), false);
   });
 }
 
 /// Set of initializers that are invoked by `initPolymer`.  This is computed the
 /// list by crawling HTML imports, searching for script tags, and including an
 /// initializer for each type tagged with a [CustomTag] annotation and for each
 /// top-level method annotated with [initMethod].
+List<Function> initializers = discoverInitializers(
+    discoverLibrariesToLoad(document, window.location.href));
+
+/// True if we're in deployment mode.
+bool deployMode = false;
 
 /// Discovers what script tags are loaded from HTML pages and collects the
 /// initializers of their corresponding libraries.
 // Visible for testing only.
-List<Function> discoverInitializers(List<String> librariesToLoad) {
+List<Function> discoverInitializers(Iterable<String> librariesToLoad) {
   var initializers = [];
   for (var lib in librariesToLoad) {
     try {
       _loadLibrary(lib, initializers);
     } catch (e, s) {
       // Deliver errors async, so if a single library fails it doesn't prevent
       // other things from loading.
       new Completer().completeError(e, s);
     }
   }
   return initializers;
 }
 
+/// 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).
+List<_ScriptInfo> _discoverScripts(Document doc, String baseUri, [_State state]) {
+  if (state == null) state = new _State();
+  if (doc == null) {
+    print('warning: $baseUri not found.');
+    return state.scripts;
+  }
+  if (!state.seen.add(doc)) return state.scripts;
+
+  for (var node in doc.querySelectorAll('script,link[rel="import"]')) {
+    if (node is LinkElement) {
+      _discoverScripts(node.import, node.href, state);
+    } else if (node is ScriptElement && node.type == 'application/dart') {
+      state.scripts.add(_scriptInfoFor(node, baseUri));
+    }
+  }
+  return state.scripts;
+}
+
+/// Internal state used in [_discoverScripts].
+class _State {
+  /// Documents that we have visited thus far.
+  final Set<Document> seen = new Set();
+
+  /// Scripts that have been discovered, in tree order.
+  final List<_ScriptInfo> scripts = [];
+}
+
+/// Holds information about a Dart script tag.
+class _ScriptInfo {
+  /// The original URL seen in the tag fully resolved.
+  final String resolvedUrl;
+
+  /// Whether there was no URL, but code inlined instead.
+  bool get isInline => text != null;
+
+  /// Whether it seems to be a 'package:' URL (starts with the package-root).
+  bool get isPackage => packageUrl != null;
+
+  /// The equivalent 'package:' URL, if any.
+  final String packageUrl;
+
+  /// The inlined text, if any.
+  final String text;
+
+  /// Returns a base64 `data:` uri with the contents of [text].
+  // TODO(sigmund): change back to application/dart: using text/javascript seems
+  // wrong but it hides a warning in Dartium (dartbug.com/18000).
+  String get dataUrl => 'data:text/javascript;base64,${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);
+
+bool _packageUrlExists(_ScriptInfo info) =>
+    info.isPackage && _libs[Uri.parse(info.packageUrl)] != null;
+
 /// All libraries in the current isolate.
 final _libs = currentMirrorSystem().libraries;
 
 final Logger _loaderLog = new Logger('polymer.src.mirror_loader');
 
 /// Reads the library at [uriString] (which can be an absolute URI or a relative
 /// URI from the root library), and:
 ///
 ///   * If present, invokes any top-level and static functions marked
 ///     with the [initMethod] annotation (in the order they appear).
@@ skipping 86 matching lines @@
         " ${method.simpleName} is not.");
     return;
   }
   if (!method.parameters.where((p) => !p.isOptional).isEmpty) {
     print("warning: methods marked with @initMethod should take no "
         "arguments, ${method.simpleName} expects some.");
     return;
   }
   initializers.add(() => obj.invoke(method.simpleName, const []));
 }