pkg/polymer/lib/src/loader.dart - sdk.git - Git at Google

 // 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.

 part of polymer;

 /** Annotation used to automatically register polymer elements. */
 class CustomTag {
   final String tagName;
   const CustomTag(this.tagName);
 }

 /**
  * Metadata used to label static or top-level methods that are called
  * automatically when loading the library of a custom element.
  */
 const initMethod = const _InitMethodAnnotation();

 /**
  * Initializes a polymer application as follows:
  *   * set up up polling for observable changes
  *   * initialize Model-Driven Views
  *   * Include some style to prevent flash of unstyled content (FOUC)
  *   * for each library in [libraries], register custom elements labeled with
  *      [CustomTag] and invoke the initialization method on it. If [libraries]
  *      is null, first find all libraries that need to be loaded by scanning for
  *      HTML imports in the main document.
  *
  * The initialization on each library is a top-level function and annotated with
  * [initMethod].
  *
  * The urls in [libraries] can be absolute or relative to
  * `currentMirrorSystem().isolate.rootLibrary.uri`.
  */
 void initPolymer() {
   if (_useDirtyChecking) {
     dirtyCheckZone().run(_initPolymerOptimized);
   } else {
     _initPolymerOptimized();
   }
 }

 /**
  * Same as [initPolymer], but runs the version that is optimized for deployment
  * to the internet. The biggest difference is it omits the [Zone] that
  * automatically invokes [Observable.dirtyCheck], and the list of libraries must
  * be supplied instead of being dynamically searched for at runtime.
  */
 // TODO(jmesserly): change the Polymer build step to call this directly.
 void _initPolymerOptimized() {
   preventFlashOfUnstyledContent();

   document.register(PolymerDeclaration._TAG, PolymerDeclaration);

   _loadLibraries();
 }

 /**
  * Configures [initPolymer] making it optimized for deployment to the internet.
  * With this setup the list of libraries to initialize is supplied instead of
  * being dynamically searched for at runtime. Additionally, after this method is
  * called, [initPolymer] omits the [Zone] that automatically invokes
  * [Observable.dirtyCheck].
  */
 void configureForDeployment(List<String> libraries) {
   _librariesToLoad = libraries;
   _useDirtyChecking = false;
 }

 /**
  * Libraries that will be initialized. For each library, the intialization
  * registers any type tagged with a [CustomTag] annotation and calls any
  * top-level method annotated with [initMethod]. The value of this field is
  * assigned programatically by the code generated from the polymer deploy
  * scripts. During development, the libraries are inferred by crawling HTML
  * imports and searching for script tags.
  */
 List<String> _librariesToLoad =
     _discoverScripts(document, window.location.href);
 bool _useDirtyChecking = true;

 void _loadLibraries() {
   for (var lib in _librariesToLoad) {
     try {
       _loadLibrary(lib);
     } 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);
     }
   }

   customElementsReady.then((_) => Polymer._ready.complete());
 }

 /**
  * 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<String> _discoverScripts(Document doc, String baseUri,
     [Set<Document> seen, List<String> scripts]) {
   if (seen == null) seen = new Set<Document>();
   if (scripts == null) scripts = <String>[];
   if (doc == null) {
     print('warning: $baseUri not found.');
     return;
   }
   if (seen.contains(doc)) return scripts;
   seen.add(doc);

   var inlinedScriptCount = 0;
   for (var node in doc.queryAll('script,link[rel="import"]')) {
     if (node is LinkElement) {
       _discoverScripts(node.import, node.href, seen, scripts);
     } else if (node is ScriptElement && node.type == 'application/dart') {
       var url = node.src;
       if (url != '') {
         // TODO(sigmund): consider either normalizing package: urls or add a
         // warning to let users know about cannonicalization issues.
         scripts.add(url);
       } else {
         // We generate a unique identifier for inlined scripts which we later
         // translate to the unique identifiers used by Dartium. Dartium uses
         // line/column number information which we can't compute here.
         scripts.add('$baseUri:$inlinedScriptCount');
         inlinedScriptCount++;
       }
     }
   }
   return scripts;
 }

 /** All libraries in the current isolate. */
 final _libs = currentMirrorSystem().libraries;

 // TODO(sigmund): explore other (cheaper) ways to resolve URIs relative to the
 // root library (see dartbug.com/12612)
 final _rootUri = currentMirrorSystem().isolate.rootLibrary.uri;

 final String _packageRoot =
     '${path.dirname(Uri.parse(window.location.href).path)}/packages/';

 /** Regex that matches urls used to represent inlined scripts. */
 final RegExp _inlineScriptRegExp = new RegExp('\(.*\.html.*\):\([0-9]\+\)');

 /**
  * Map URLs fabricated by polymer to URLs fabricated by Dartium to represent
  * inlined scripts. Polymer uses baseUri:script#, Dartium uses baseUri:line#
  */
 // TODO(sigmund): figure out if we can generate the same URL and expose it.
 final Map<Uri, List<Uri>> _inlinedScriptMapping = () {
   var map = {};
   for (var uri in _libs.keys) {
     var uriString = uri.toString();
     var match = _inlineScriptRegExp.firstMatch(uriString);
     if (match == null) continue;
     var baseUri = Uri.parse(match.group(1));
     if (map[baseUri] == null) map[baseUri] = [];
     map[baseUri].add(uri);
   }
   return map;
 }();

 /** Returns a new Uri that replaces [path] in [uri]. */
 Uri _replacePath(Uri uri, String path) {
   return new Uri(scheme: uri.scheme, host: uri.host, port: uri.port,
       path: path, query: uri.query, fragment: uri.fragment);
 }

 /** Returns the Uri in [href] without query parameters or fragments. */
 String _baseUri(String href) {
   var uri = Uri.parse(window.location.href);
   var trimUri = new Uri(scheme: uri.scheme, host: uri.host,
       port: uri.port, path: uri.path);
   return trimUri.toString();
 }

 /**
  * 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).
  *
  *   * Registers any [PolymerElement] that is marked with the [CustomTag]
  *     annotation.
  */
 void _loadLibrary(String uriString) {
   var uri = _rootUri.resolve(uriString);
   var lib;
   var match = _inlineScriptRegExp.firstMatch(uriString);
   if (match != null) {
     var baseUri = Uri.parse(match.group(1));
     var list = _inlinedScriptMapping[baseUri];
     var pos = int.parse(match.group(2), onError: (_) => -1);
     if (list != null && pos >= 0 && pos < list.length && list[pos] != null) {
       lib = _libs[list[pos]];
     }
   } else if (uri.path.startsWith(_packageRoot)) {
     var packageUri =
         Uri.parse('package:${uri.path.substring(_packageRoot.length)}');
     lib = _libs[packageUri];
     if (lib == null) {
       lib = _libs[uri];
     }
   } else {
     lib = _libs[uri];
   }
   if (lib == null) {
     print('warning: $uri library not found');
     return;
   }

   // Search top-level functions marked with @initMethod
   for (var f in lib.functions.values) {
     _maybeInvoke(lib, f);
   }

   for (var c in lib.classes.values) {
     // Search for @CustomTag on classes
     for (var m in c.metadata) {
       var meta = m.reflectee;
       if (meta is CustomTag) {
         Polymer.register(meta.tagName, getReflectedTypeWorkaround(c));
       }
     }

     // TODO(sigmund): check also static methods marked with @initMethod.
     // This is blocked on two bugs:
     //  - dartbug.com/12133 (static methods are incorrectly listed as top-level
     //    in dart2js, so they end up being called twice)
     //  - dartbug.com/12134 (sometimes "method.metadata" throws an exception,
     //    we could wrap and hide those exceptions, but it's not ideal).
   }
 }

 void _maybeInvoke(ObjectMirror obj, MethodMirror method) {
   var annotationFound = false;
   for (var meta in method.metadata) {
     if (identical(meta.reflectee, initMethod)) {
       annotationFound = true;
       break;
     }
   }
   if (!annotationFound) return;
   if (!method.isStatic) {
     print("warning: methods marked with @initMethod should be static,"
         " ${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;
   }
   obj.invoke(method.simpleName, const []);
 }

 class _InitMethodAnnotation {
   const _InitMethodAnnotation();
 }
	// 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.

	part of polymer;

	/** Annotation used to automatically register polymer elements. */
	class CustomTag {
	final String tagName;
	const CustomTag(this.tagName);
	}

	/**
	* Metadata used to label static or top-level methods that are called
	* automatically when loading the library of a custom element.
	*/
	const initMethod = const _InitMethodAnnotation();

	/**
	* Initializes a polymer application as follows:
	* * set up up polling for observable changes
	* * initialize Model-Driven Views
	* * Include some style to prevent flash of unstyled content (FOUC)
	* * for each library in [libraries], register custom elements labeled with
	* [CustomTag] and invoke the initialization method on it. If [libraries]
	* is null, first find all libraries that need to be loaded by scanning for
	* HTML imports in the main document.
	*
	* The initialization on each library is a top-level function and annotated with
	* [initMethod].
	*
	* The urls in [libraries] can be absolute or relative to
	* `currentMirrorSystem().isolate.rootLibrary.uri`.
	*/
	void initPolymer() {
	if (_useDirtyChecking) {
	dirtyCheckZone().run(_initPolymerOptimized);
	} else {
	_initPolymerOptimized();
	}
	}

	/**
	* Same as [initPolymer], but runs the version that is optimized for deployment
	* to the internet. The biggest difference is it omits the [Zone] that
	* automatically invokes [Observable.dirtyCheck], and the list of libraries must
	* be supplied instead of being dynamically searched for at runtime.
	*/
	// TODO(jmesserly): change the Polymer build step to call this directly.
	void _initPolymerOptimized() {
	preventFlashOfUnstyledContent();

	document.register(PolymerDeclaration._TAG, PolymerDeclaration);

	_loadLibraries();
	}

	/**
	* Configures [initPolymer] making it optimized for deployment to the internet.
	* With this setup the list of libraries to initialize is supplied instead of
	* being dynamically searched for at runtime. Additionally, after this method is
	* called, [initPolymer] omits the [Zone] that automatically invokes
	* [Observable.dirtyCheck].
	*/
	void configureForDeployment(List<String> libraries) {
	_librariesToLoad = libraries;
	_useDirtyChecking = false;
	}

	/**
	* Libraries that will be initialized. For each library, the intialization
	* registers any type tagged with a [CustomTag] annotation and calls any
	* top-level method annotated with [initMethod]. The value of this field is
	* assigned programatically by the code generated from the polymer deploy
	* scripts. During development, the libraries are inferred by crawling HTML
	* imports and searching for script tags.
	*/
	List<String> _librariesToLoad =
	_discoverScripts(document, window.location.href);
	bool _useDirtyChecking = true;

	void _loadLibraries() {
	for (var lib in _librariesToLoad) {
	try {
	_loadLibrary(lib);
	} 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);
	}
	}

	customElementsReady.then((_) => Polymer._ready.complete());
	}

	/**
	* 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<String> _discoverScripts(Document doc, String baseUri,
	[Set<Document> seen, List<String> scripts]) {
	if (seen == null) seen = new Set<Document>();
	if (scripts == null) scripts = <String>[];
	if (doc == null) {
	print('warning: $baseUri not found.');
	return;
	}
	if (seen.contains(doc)) return scripts;
	seen.add(doc);

	var inlinedScriptCount = 0;
	for (var node in doc.queryAll('script,link[rel="import"]')) {
	if (node is LinkElement) {
	_discoverScripts(node.import, node.href, seen, scripts);
	} else if (node is ScriptElement && node.type == 'application/dart') {
	var url = node.src;
	if (url != '') {
	// TODO(sigmund): consider either normalizing package: urls or add a
	// warning to let users know about cannonicalization issues.
	scripts.add(url);
	} else {
	// We generate a unique identifier for inlined scripts which we later
	// translate to the unique identifiers used by Dartium. Dartium uses
	// line/column number information which we can't compute here.
	scripts.add('$baseUri:$inlinedScriptCount');
	inlinedScriptCount++;
	}
	}
	}
	return scripts;
	}

	/** All libraries in the current isolate. */
	final _libs = currentMirrorSystem().libraries;

	// TODO(sigmund): explore other (cheaper) ways to resolve URIs relative to the
	// root library (see dartbug.com/12612)
	final _rootUri = currentMirrorSystem().isolate.rootLibrary.uri;

	final String _packageRoot =
	'${path.dirname(Uri.parse(window.location.href).path)}/packages/';

	/** Regex that matches urls used to represent inlined scripts. */
	final RegExp _inlineScriptRegExp = new RegExp('\(.\.html.\):\([0-9]\+\)');

	/**
	* Map URLs fabricated by polymer to URLs fabricated by Dartium to represent
	* inlined scripts. Polymer uses baseUri:script#, Dartium uses baseUri:line#
	*/
	// TODO(sigmund): figure out if we can generate the same URL and expose it.
	final Map<Uri, List<Uri>> _inlinedScriptMapping = () {
	var map = {};
	for (var uri in _libs.keys) {
	var uriString = uri.toString();
	var match = _inlineScriptRegExp.firstMatch(uriString);
	if (match == null) continue;
	var baseUri = Uri.parse(match.group(1));
	if (map[baseUri] == null) map[baseUri] = [];
	map[baseUri].add(uri);
	}
	return map;
	}();

	/** Returns a new Uri that replaces [path] in [uri]. */
	Uri _replacePath(Uri uri, String path) {
	return new Uri(scheme: uri.scheme, host: uri.host, port: uri.port,
	path: path, query: uri.query, fragment: uri.fragment);
	}

	/** Returns the Uri in [href] without query parameters or fragments. */
	String _baseUri(String href) {
	var uri = Uri.parse(window.location.href);
	var trimUri = new Uri(scheme: uri.scheme, host: uri.host,
	port: uri.port, path: uri.path);
	return trimUri.toString();
	}

	/**
	* 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).
	*
	* * Registers any [PolymerElement] that is marked with the [CustomTag]
	* annotation.
	*/
	void _loadLibrary(String uriString) {
	var uri = _rootUri.resolve(uriString);
	var lib;
	var match = _inlineScriptRegExp.firstMatch(uriString);
	if (match != null) {
	var baseUri = Uri.parse(match.group(1));
	var list = _inlinedScriptMapping[baseUri];
	var pos = int.parse(match.group(2), onError: (_) => -1);
	if (list != null && pos >= 0 && pos < list.length && list[pos] != null) {
	lib = _libs[list[pos]];
	}
	} else if (uri.path.startsWith(_packageRoot)) {
	var packageUri =
	Uri.parse('package:${uri.path.substring(_packageRoot.length)}');
	lib = _libs[packageUri];
	if (lib == null) {
	lib = _libs[uri];
	}
	} else {
	lib = _libs[uri];
	}
	if (lib == null) {
	print('warning: $uri library not found');
	return;
	}

	// Search top-level functions marked with @initMethod
	for (var f in lib.functions.values) {
	_maybeInvoke(lib, f);
	}

	for (var c in lib.classes.values) {
	// Search for @CustomTag on classes
	for (var m in c.metadata) {
	var meta = m.reflectee;
	if (meta is CustomTag) {
	Polymer.register(meta.tagName, getReflectedTypeWorkaround(c));
	}
	}

	// TODO(sigmund): check also static methods marked with @initMethod.
	// This is blocked on two bugs:
	// - dartbug.com/12133 (static methods are incorrectly listed as top-level
	// in dart2js, so they end up being called twice)
	// - dartbug.com/12134 (sometimes "method.metadata" throws an exception,
	// we could wrap and hide those exceptions, but it's not ideal).
	}
	}

	void _maybeInvoke(ObjectMirror obj, MethodMirror method) {
	var annotationFound = false;
	for (var meta in method.metadata) {
	if (identical(meta.reflectee, initMethod)) {
	annotationFound = true;
	break;
	}
	}
	if (!annotationFound) return;
	if (!method.isStatic) {
	print("warning: methods marked with @initMethod should be static,"
	" ${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;
	}
	obj.invoke(method.simpleName, const []);
	}

	class _InitMethodAnnotation {
	const _InitMethodAnnotation();
	}