fix #136, support watch exprs and two way bindings for component fields

lib/src/info.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Datatypes holding information extracted by the analyzer and used by later
  * phases of the compiler.
  */
 library info;
 
@@ skipping 276 matching lines @@
   }
 
   /**
    * True if [tagName] was defined by more than one component. If this happened
    * we will skip over the component.
    */
   bool hasConflict = false;
 
   ComponentInfo(this.element, this.declaringFile, this.tagName, this.extendsTag,
       this.constructor, this.template);
+
+  /**
+   * Gets the HTML tag extended by the base of the component hierarchy.
+   * Equivalent to [extendsTag] if this inherits directly from an HTML element,
+   * in other words, if [extendsComponent] is null.
+   */
+  String get baseExtendsTag =>
+      extendsComponent == null ? extendsTag : extendsComponent.baseExtendsTag;
 }
 
 /** Base tree visitor for the Analyzer infos. */
 class InfoVisitor {
   visit(info) {
     if (info == null) return;
     if (info is TemplateInfo) {
       return visitTemplateInfo(info);
     } else if (info is ElementInfo) {
       return visitElementInfo(info);
@@ skipping 89 matching lines @@
   // preserve the order of the input, but we'd need to be careful about our tree
   // traversal order.
   /** Collected information for attributes, if any. */
   final Map<String, AttributeInfo> attributes =
       new SplayTreeMap<String, AttributeInfo>();
 
   /** Collected information for UI events on the corresponding element. */
   final Map<String, List<EventInfo>> events =
       new SplayTreeMap<String, List<EventInfo>>();
 
-  /** Collected information about `data-value="name:value"` expressions. */
+  /**
+   * Collected information about `data-value="name:value"` expressions.
+   * Note: this feature is deprecated and should be removed after grace period.
+   */
   final Map<String, String> values = new SplayTreeMap<String, String>();
 
   // TODO(jmesserly): we could keep this local to the analyzer.
   /** Attribute names to remove in cleanup phase. */
   final Set<String> removeAttributes = new Set<String>();
 
   /** Whether the template element has `iterate="... in ...". */
   bool get hasIterate => false;
 
   /** Whether the template element has an `if="..."` conditional. */
   bool get hasIfCondition => false;
 
   bool get isTemplateElement => false;
 
+  /**
+   * For a builtin HTML element this returns the [node.tagName], otherwise it
+   * returns [component.baseExtendsTag]. This is useful when looking up which
+   * DOM property this element supports.
+   *
+   * **Note:** this returns node.tagName right now, until we fix issue #82.
+   */
+  String get baseTagName {
+    return node.tagName;
+    // TODO(jmesserly): turn this on when issue #82 is fixed.
+    //return component != null ? component.baseExtendsTag : node.tagName;
+  }
+
   ElementInfo(Element node, ElementInfo parent) : super(node, parent);
 
   String toString() => '#<ElementInfo '
       'identifier: $identifier, '
       'childrenCreatedInCode: $childrenCreatedInCode, '
       'component: $component, '
       'hasIterate: $hasIterate, '
       'hasIfCondition: $hasIfCondition, '
       'hasDataBinding: $hasDataBinding, '
       'hasQuery: $hasQuery, '
@@ skipping 27 matching lines @@
 
   /**
    * Whether this is a 'data-style' attribute.
    */
   final bool isStyle;
 
   /** All bound values that would be monitored for changes. */
   final List<String> bindings;
 
   /**
+   * A two-way binding that needs a watcher. This is used in cases where we
+   * don't have an event.
+   */
+  final bool customTwoWayBinding;
+
+  /**
    * For a text attribute this contains the text content. This is used by most
    * attributes and represents the value that will be assigned to them. If this
    * has been assigned then [isText] will be true.
    *
    * The entries in this list correspond to the entries in [bindings], and this
    * will always have one more item than bindings. For example:
    *
    *     href="t0 {{b1}} t1 {{b2}} t2"
    *
    * Here textContent would be `["t0 ", " t1 ", " t2"]` and bindings would be
    * `["b1", "b2"]`.
    */
   final List<String> textContent;
 
   AttributeInfo(this.bindings, {this.isStyle: false, this.isClass: false,
-      this.textContent}) {
+      this.textContent, this.customTwoWayBinding: false}) {
 
     assert(isText || isClass || bindings.length == 1);
     assert(bindings.length > 0);
     assert(!isText || textContent.length == bindings.length + 1);
     assert((isText ? 1 : 0) + (isClass ? 1 : 0) + (isStyle ? 1 : 0) <= 1);
   }
 
   /**
    * A value that will be monitored for changes. All attributes have a single
    * bound value unless [isClass] or [isText] is true.
@@ skipping 137 matching lines @@
   }
 
   visitChildren(ElementInfo info) {
     for (var child in info.children) {
       var result = visit(child);
       if (result != null) return result;
     }
     return null;
   }
 }