Create implementation file emitter in HtmlDartInterfaceGenerator.

lib/dom/scripts/systemhtml.py

Index: lib/dom/scripts/systemhtml.py
diff --git a/lib/dom/scripts/systemhtml.py b/lib/dom/scripts/systemhtml.py
index 3b3b418885a120c26a454006f90c8ef7ac0d4bcd..1585eed512e9f9922f2f4bdd69caea17d5073773 100644
--- a/lib/dom/scripts/systemhtml.py
+++ b/lib/dom/scripts/systemhtml.py
@@ -6,6 +6,8 @@
 """This module provides shared functionality for the system to generate
 Dart:html APIs from the IDL database."""
 
+import emitter
+
 from systemfrog import *
 from systeminterface import *
 
@@ -775,30 +777,8 @@ class HtmlInterfacesSystem(HtmlSystem):
     self._factory_provider_emitters = {}
 
   def ProcessInterface(self, interface):
-    """."""
-
-    self._backend.ProcessInterface(interface)
-
-    if interface.id in _merged_html_interfaces:
-      return
-
-    html_interface_name = self._shared._HTMLInterfaceName(interface.id)
-    dart_interface_file_path = self._FilePathForDartInterface(
-        html_interface_name)
-
-    self._dart_interface_file_paths.append(dart_interface_file_path)
-
-    dart_interface_code = self._emitters.FileEmitter(dart_interface_file_path)
-
-    template_file = 'interface_%s.darttemplate' % html_interface_name
-    template = self._templates.TryLoad(template_file)
-    if not template:
-      template = self._templates.Load('interface.darttemplate')
-
-    generator = HtmlDartInterfaceGenerator(
-        self, interface, dart_interface_code,
-        template, self._shared)
-    generator.Generate()
+    """Generates dart interface and implementation for the DOM IDL interface."""
+    HtmlDartInterfaceGenerator(self, interface).Generate()
 
   def ProcessCallback(self, interface, info):
     """Generates a typedef for the callback interface."""
@@ -818,19 +798,46 @@ class HtmlInterfacesSystem(HtmlSystem):
 
 # ------------------------------------------------------------------------------
 
-# TODO(jmesserly): inheritance is probably not the right way to factor this long
-# term, but it makes merging better for now.
-class HtmlDartInterfaceGenerator(DartInterfaceGenerator):
-  """Generates Dart Interface definition for one DOM IDL interface."""
-
-  def __init__(self, system, interface, emitter, template, shared):
-    super(HtmlDartInterfaceGenerator, self).__init__(system, interface,
-      emitter, template)
-    self._shared = shared
+class HtmlDartInterfaceGenerator(BaseGenerator):
+  """Generates dart interface and implementation for the DOM IDL interface."""
+
+  def __init__(self, system, interface):
+    super(HtmlDartInterfaceGenerator, self).__init__(
+        system._database, interface)
+    self._system = system

[Anton Muhin, 2012/06/28 13:20:19]

do you need to store system here too (it's passed into super ctor?)

[podivilov, 2012/06/29 12:59:28]

No, it's not passed.

[Anton Muhin, 2012/06/29 13:34:57]

Maybe you should pass it, but I am not insisting on it, and definitely not now.

On 2012/06/29 12:59:28, podivilov wrote:

+    self._backend = system._backend
+    self._emitters = system._emitters
+    self._shared = system._shared
+    self._templates = system._templates

[Anton Muhin, 2012/06/28 13:20:19]

why are you caching _backend, _emitters, _shared and _templates?

[podivilov, 2012/06/29 12:59:28]

Done.

     self._html_interface_name = self._shared._HTMLInterfaceName(
         self._interface.id)
 
+    interface_path = self._system._FilePathForDartInterface(

[Anton Muhin, 2012/06/28 13:20:19]

it looks like interface_path is only used in then clause of conditional below,
may it go in there?

[podivilov, 2012/06/29 12:59:28]

Done.

+        self._html_interface_name)
+    if not interface.id in _merged_html_interfaces:
+      self._system._dart_interface_file_paths.append(interface_path)

[Anton Muhin, 2012/06/28 13:20:19]

again, why you need _system here, or are you going to move things around bit by
bit?

[podivilov, 2012/06/29 12:59:28]

_dart_interface_file_paths is per-library state, let's keep it in system for
now.

+      self._interface_emitter = self._emitters.FileEmitter(interface_path)
+    else:
+      self._interface_emitter = emitter.Emitter()
+
+    template_file = 'interface_%s.darttemplate' % self._html_interface_name
+    self._interface_template = (self._templates.TryLoad(template_file) or
+                                self._templates.Load('interface.darttemplate'))
+
+    implementation_path = self._backend.FilePathForDartImplementation(

[Anton Muhin, 2012/06/28 13:20:19]

ditto for implementation_path and if below.

[podivilov, 2012/06/29 12:59:28]

Done.

+        self._interface.id)
+    if self._backend.HasImplementation(self._interface.id):
+      self._system._dart_interface_file_paths.append(implementation_path)

[Anton Muhin, 2012/06/28 13:20:19]

that looks slightly odd that you add implementation path into interface file
paths' list.

[podivilov, 2012/06/29 12:59:28]

This is slightly complicated to refactor right now, because
_dart_interface_file_paths is used by SystemBase and shared with dom systems.
Let's keep for now.

+      self._implementation_emitter = self._emitters.FileEmitter(
+          implementation_path)
+    else:
+      self._implementation_emitter = emitter.Emitter()
+
   def StartInterface(self):
+    if not IsPureInterface(self._interface.id):

[Anton Muhin, 2012/06/28 13:20:19]

that might be stupid, but it feels more natural to me to generate interface
first and then implementation.

[Anton Muhin, 2012/06/28 13:20:19]

should you call into backend if it's not pure or if it
_backend.HasImplementation()?

[podivilov, 2012/06/29 12:59:28]

Done.

[podivilov, 2012/06/29 12:59:28]

Done.

+      self._backend.ProcessInterface(
+          self._interface, self._implementation_emitter)
+
     typename = self._html_interface_name
 
     extends = []
@@ -881,8 +888,8 @@ class HtmlDartInterfaceGenerator(DartInterfaceGenerator):
     # TODO(vsm): Add appropriate package / namespace syntax.
     (self._type_comment_emitter,
      self._members_emitter,
-     self._top_level_emitter) = self._emitter.Emit(
-         self._template + '$!TOP_LEVEL',
+     self._top_level_emitter) = self._interface_emitter.Emit(
+         self._interface_template + '$!TOP_LEVEL',
          ID=typename,
          EXTENDS=extends_str)
 
@@ -982,7 +989,11 @@ class HtmlDartInterfaceGenerator(DartInterfaceGenerator):
     pass
 
   def AddConstant(self, constant):
-    self._EmitConstant(self._members_emitter, constant)
+    type = TypeOrNothing(DartType(constant.type.id), constant.type.id)
+    self._members_emitter.Emit('\n  static final $TYPE$NAME = $VALUE;\n',
+                               NAME=constant.id,
+                               TYPE=type,
+                               VALUE=constant.value)
 
   def AddEventAttributes(self, event_attrs):
     event_attrs = DomToHtmlEvents(self._html_interface_name, event_attrs)
@@ -990,7 +1001,7 @@ class HtmlDartInterfaceGenerator(DartInterfaceGenerator):
     events_interface = self._html_interface_name + 'Events'
     self._EmitEventGetter(events_interface)
 
-    events_members = self._emitter.Emit(
+    events_members = self._interface_emitter.Emit(
         '\ninterface $INTERFACE extends $PARENTS {\n$!MEMBERS}\n',
         INTERFACE=events_interface,
         PARENTS=', '.join(
@@ -1351,23 +1362,16 @@ class HtmlFrogSystem(HtmlSystem):
     self._dart_frog_file_paths = []
     self._factory_provider_emitters = {}
 
-  def ProcessInterface(self, interface):
+  def ProcessInterface(self, interface, implementation_emitter):
     """."""
-    if interface.id in _merged_html_interfaces:
-      return None
-
-    if IsPureInterface(interface.id):
-      return
-
     html_interface_name = self._shared._HTMLInterfaceName(interface.id)
     template_file = 'impl_%s.darttemplate' % html_interface_name
     template = self._templates.TryLoad(template_file)
     if not template:
       template = self._templates.Load('frog_impl.darttemplate')
 
-    dart_code = self._ImplFileEmitter(html_interface_name)
     generator = HtmlFrogClassGenerator(self, interface, template,
-                                       dart_code, self._shared)
+                                       implementation_emitter, self._shared)
     generator.Generate()
 
   def GenerateLibraries(self, interface_files):
@@ -1379,9 +1383,13 @@ class HtmlFrogSystem(HtmlSystem):
   def Finish(self):
     pass
 
+  def HasImplementation(self, interface):
+    return not (IsPureInterface(interface) or
+                interface in _merged_html_interfaces)
+
   def _ImplFileEmitter(self, name):
     """Returns the file emitter of the Frog implementation file."""
-    path = os.path.join(self._output_dir, 'html', 'frog', '%s.dart' % name)
+    path = self.FilePathForDartImplementation(name)
     self._dart_frog_file_paths.append(path)
     return self._emitters.FileEmitter(path)
 
@@ -1392,6 +1400,10 @@ class HtmlFrogSystem(HtmlSystem):
       self._factory_provider_emitters[name] = file_emitter.Emit(template)
     return self._factory_provider_emitters[name]
 
+  def FilePathForDartImplementation(self, name):
+    name = self._shared._HTMLInterfaceName(name)
+    return os.path.join(self._output_dir, 'html', 'frog', '%s.dart' % name)
+
 # -----------------------------------------------------------------------------
 
 def _ComputeInheritanceClosure(database):