JSON schema compiler: Read the "optional" property out of the JSON for Function.

tools/json_schema_compiler/model.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import copy
 import os.path
 import re
 
 class ParseException(Exception):
   """Thrown when data in the model is invalid.
@@ skipping 96 matching lines @@
 class Function(object):
   """A Function defined in the API.
 
   Properties:
   - |name| the function name
   - |params| a list of parameters to the function (order matters). A separate
     parameter is used for each choice of a 'choices' parameter.
   - |description| a description of the function (if provided)
   - |callback| the callback parameter to the function. There should be exactly
     one
+  - |optional| whether the Function is "optional"; this only makes sense to be
+    present when the Function is representing a callback property.
   """
   def __init__(self, parent, json, from_json=False, from_client=False):
     self.name = json['name']
     self.params = []
     self.description = json.get('description')
     self.callback = None
+    self.optional = json.get('optional', False)
     self.parent = parent
     self.nocompile = json.get('nocompile')
     for param in json.get('parameters', []):
       if param.get('type') == 'function':
         if self.callback:
           raise ParseException(self, self.name + " has more than one callback")
         self.callback = Function(self, param, from_client=True)
       else:
         self.params.append(Property(self, param['name'], param,
             from_json=from_json, from_client=from_client))
@@ skipping 216 matching lines @@
     # handled in pure Javascript on the render process (and .: never reach
     # C++ let alone the browser).
     if property_json.get('type') == 'function':
       continue
     model.properties[name] = Property(
         model,
         name,
         property_json,
         from_json=from_json,
         from_client=from_client)