| // 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. |
| |
| part of dart.dom.html; |
| |
| /// Dartium ElementUpgrader implementation. |
| class _VMElementUpgrader implements ElementUpgrader { |
| final Type _type; |
| final Type _nativeType; |
| final String _extendsTag; |
| |
| _VMElementUpgrader(Document document, Type type, String extendsTag) : |
| _type = type, |
| _extendsTag = extendsTag, |
| _nativeType = _validateCustomType(type).reflectedType { |
| |
| if (extendsTag == null) { |
| if (_nativeType != HtmlElement) { |
| throw new UnsupportedError('Class must provide extendsTag if base ' |
| 'native class is not HtmlElement'); |
| } |
| } else { |
| if (document.createElement(extendsTag).runtimeType != _nativeType) { |
| throw new UnsupportedError( |
| 'extendsTag does not match base native class'); |
| } |
| } |
| } |
| |
| Element upgrade(element) { |
| var jsObject; |
| var tag; |
| var isNativeElementExtension = false; |
| |
| try { |
| tag = _getCustomElementName(element); |
| } catch (e) { |
| isNativeElementExtension = element.localName == _extendsTag; |
| } |
| |
| if (element.runtimeType == HtmlElement || element.runtimeType == TemplateElement) { |
| if (tag != _extendsTag) { |
| throw new UnsupportedError('$tag is not registered.'); |
| } |
| jsObject = unwrap_jso(element); |
| } else if (element.runtimeType == js.JsObject) { |
| // It's a Polymer core element (written in JS). |
| jsObject = element; |
| } else if (isNativeElementExtension) { |
| // Extending a native element. |
| jsObject = element.blink_jsObject; |
| |
| // Element to extend is the real tag. |
| tag = element.localName; |
| } else if (tag != null && element.localName != tag) { |
| throw new UnsupportedError('Element is incorrect type. Got ${element.runtimeType}, expected native Html or Svg element to extend.'); |
| } else if (tag == null) { |
| throw new UnsupportedError('Element is incorrect type. Got ${element.runtimeType}, expected HtmlElement/JsObject.'); |
| } |
| |
| // Remember Dart class to tagName for any upgrading done in wrap_jso. |
| addCustomElementType(tag, _type, _extendsTag); |
| |
| return _createCustomUpgrader(_type, jsObject); |
| } |
| } |
| |
| /// Validates that the custom type is properly formed- |
| /// |
| /// * Is a user-defined class. |
| /// * Has a created constructor with zero args. |
| /// * Derives from an Element subclass. |
| /// |
| /// Then returns the native base class. |
| ClassMirror _validateCustomType(Type type) { |
| ClassMirror cls = reflectClass(type); |
| if (_isBuiltinType(cls)) { |
| throw new UnsupportedError('Invalid custom element from ' |
| '${(cls.owner as LibraryMirror).uri}.'); |
| } |
| |
| var className = MirrorSystem.getName(cls.simpleName); |
| if (cls.isAbstract) { |
| throw new UnsupportedError('Invalid custom element ' |
| 'class $className is abstract.'); |
| } |
| |
| var createdConstructor = cls.declarations[new Symbol('$className.created')]; |
| if (createdConstructor == null || |
| createdConstructor is! MethodMirror || |
| !createdConstructor.isConstructor) { |
| throw new UnsupportedError( |
| 'Class is missing constructor $className.created'); |
| } |
| |
| if (createdConstructor.parameters.length > 0) { |
| throw new UnsupportedError( |
| 'Constructor $className.created must take zero arguments'); |
| } |
| |
| Symbol objectName = reflectClass(Object).qualifiedName; |
| bool isRoot(ClassMirror cls) => |
| cls == null || cls.qualifiedName == objectName; |
| Symbol elementName = reflectClass(HtmlElement).qualifiedName; |
| bool isElement(ClassMirror cls) => |
| cls != null && cls.qualifiedName == elementName; |
| ClassMirror superClass = cls.superclass; |
| ClassMirror nativeClass = _isBuiltinType(superClass) ? superClass : null; |
| while(!isRoot(superClass) && !isElement(superClass)) { |
| superClass = superClass.superclass; |
| if (nativeClass == null && _isBuiltinType(superClass)) { |
| nativeClass = superClass; |
| } |
| } |
| return nativeClass; |
| } |
| |
| |
| bool _isBuiltinType(ClassMirror cls) { |
| // TODO(vsm): Find a less hackish way to do this. |
| LibraryMirror lib = cls.owner; |
| String libName = lib.uri.toString(); |
| return libName.startsWith('dart:'); |
| } |