Dynamically generate a heading for Extension Docs API pages

chrome/common/extensions/docs/server2/availability_data_source.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.
+
+from file_system import FileNotFoundError
+import object_store
+
+class AvailabilityDataSource:

[cduvall, 2013/03/25 22:59:43]

Class level comment about what this does.

[epeterson, 2013/03/27 22:36:09]

Done.

+  def __init__(self,
+               version_data_source,
+               version_number,
+               object_store):
+    self._version_data_source = version_data_source
+    self._version_number = version_number
+    self._object_store = object_store
+
+  def FindEarliestAvailability(self, api_name):
+    """Searches in descending order through filesystem caches tied to specific
+    chrome version numbers and looks for the existence of a specified api,
+    |api_name|. When an api is not found, returns the previous version number
+    (the last known version where the api was found).
+    """
+    version = self._object_store.Get(
+        api_name,
+        object_store.AVAILABILITY_DATA_SOURCE).Get()
+
+    if version is not None:
+      return version
+
+    version_number = int(self._version_number)
+    # extension api's are not present before version 18

[cduvall, 2013/03/25 22:59:43]

Full sentence with proper punctuation for all comments

[epeterson, 2013/03/27 22:36:09]

Done.

+    while version_number >= 18:
+      api_data_source = self._version_data_source.GetDataSourceForVersion(
+          '%d' % version_number)
+      try:
+        api_data_source.tryGet(api_name)
+      except FileNotFoundError:
+        try:
+          api_data_source.tryGet(api_name, try_non_unix=True)
+        except FileNotFoundError:
+          break
+      version_number -= 1
+
+    version_number += 1
+    # if version_number is greater than self._version_number, then the api was
+    # not found in the current version
+    if version_number > self._version_number:
+      version = 'Not available yet'
+    else:
+      version = '%d' % version_number
+    self._object_store.Set(api_name,
+                           version,
+                           object_store.AVAILABILITY_DATA_SOURCE)
+    return version