Docserver: Add support for viewing docs with a codereview patch applied

chrome/common/extensions/docs/server2/patch_servlet.py

+# Copyright 2013 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 appengine_wrappers import IsDevServer
+from object_store_creator import ObjectStoreCreator
+from render_servlet import RenderServlet
+from server_instance import ServerInstance
+from servlet import Request, Response, Servlet
+
+class PatchServlet(Servlet):
+  '''Servlet which renders patched docs.
+  '''
+
+  def Get(self):
+    path_with_issue = self._request.path
+    if '/' in path_with_issue:
+      issue, real_path = path_with_issue.split('/', 1)
+    else:
+      issue, real_path = path_with_issue, ''
+
+    constructor = (ServerInstance.CreateOnline if IsDevServer() else
+                   ServerInstance.GetOrCreateOffline)
+    server_instance = constructor('trunk',
+                                  '/_patch/%s/static' % issue,
+                                  issue)
+    fake_path = '/trunk/%s' % real_path
+
+    response = RenderServlet(Request(
+        fake_path,
+        self._request.headers)).Get(server_instance)
+
+    if response.IsRedirect():
+      url = response.headers['Location']
+      if url.startswith('/trunk/'):
+        url = url.split('/trunk', 1)[1]
+      response.headers['Location'] = '/_patch/%s%s' % (issue, url)
+    return response