HTML types that don't have [] do not implement JavaScriptIndexingBehavior, that is, the items canno…

tools/dom/scripts/systemhtml.py

 #!/usr/bin/python
 # 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.
 
 """This module provides shared functionality for the system to generate
 Dart:html APIs from the IDL database."""
 
 import emitter
 import logging
@@ skipping 633 matching lines @@
     return True
 
   def GenerateCallback(self, info):
     pass
 
   def RootClassName(self):
     return None
 
   def AdditionalImplementedInterfaces(self):
     implements = super(Dart2JSBackend, self).AdditionalImplementedInterfaces()
-    if self._interface_type_info.list_item_type():
+    if self._interface_type_info.list_item_type() and self.HasIndexedGetter():
       implements.append('JavaScriptIndexingBehavior')
     return implements
 
   def NativeSpec(self):
     native_spec = MakeNativeSpec(self._interface.javascript_binding_name)
     return ' native "%s"' % native_spec
 
   def ImplementationTemplate(self):
     template_file = ('impl_%s.darttemplate' %
                      self._interface.doc_js_name)
@@ skipping 46 matching lines @@
         PARAMETERS=constructor_info.ParametersAsArgumentList(index),
         CTOR_NAME=constructor_info.name or self._interface.doc_js_name,
         PLACEHOLDERS=','.join(['#'] * index),
         ARGUMENTS=arguments)
 
   def SecondaryContext(self, interface):
     if interface is not self._current_secondary_parent:
       self._current_secondary_parent = interface
       self._members_emitter.Emit('\n  // From $WHERE\n', WHERE=interface.id)
 
+  def HasIndexedGetter(self):
+    ext_attrs = self._interface.ext_attrs
+    has_indexed_getter = 'CustomIndexedGetter' in ext_attrs
+    for operation in self._interface.operations:
+      if operation.id == 'item' and 'getter' in operation.specials:
+        has_indexed_getter = True
+        break
+    return has_indexed_getter
+
   def AddIndexer(self, element_type):
     """Adds all the methods required to complete implementation of List."""
     # We would like to simply inherit the implementation of everything except
     # length, [], and maybe []=.  It is possible to extend from a base
     # array implementation class only when there is no other implementation
     # inheritance.  There might be no implementation inheritance other than
     # DOMBaseWrapper for many classes, but there might be some where the
     # array-ness is introduced by a non-root interface:
     #
     #   interface Y extends X, List<T> ...
     #
     # In the non-root case we have to choose between:
     #
     #   class YImpl extends XImpl { add List<T> methods; }
     #
     # and
     #
     #   class YImpl extends ListBase<T> { copies of transitive XImpl methods; }
     #
 
-    ext_attrs = self._interface.ext_attrs
-    has_indexed_getter = 'CustomIndexedGetter' in ext_attrs
-    for operation in self._interface.operations:
-      if operation.id == 'item' and 'getter' in operation.specials:
-        has_indexed_getter = True
-        break
+    has_indexed_getter = self.HasIndexedGetter()
 
     if has_indexed_getter:
       indexed_getter = ('JS("%s", "#[#]", this, index)' %
           self.SecureOutputType(element_type));
     elif any(op.id == 'getItem' for op in self._interface.operations):
       indexed_getter = 'this.getItem(index)'
     elif any(op.id == 'item' for op in self._interface.operations):
       indexed_getter = 'this.item(index)'
 
     if indexed_getter:
@@ skipping 460 matching lines @@
     for library_name in libraries:
       self._libraries[library_name] = DartLibrary(
           library_name, template_loader, library_type, output_dir)
 
   def AddFile(self, basename, library_name, path):
     self._libraries[library_name].AddFile(path)
 
   def Emit(self, emitter, auxiliary_dir):
     for lib in self._libraries.values():
       lib.Emit(emitter, auxiliary_dir)