src/chrome/common/extensions/docs/server2/render_servlet.py

   1 # Copyright 2013 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 import logging
   6 import posixpath
   7 import traceback
   8
   9 from branch_utility import BranchUtility
  10 from environment import IsPreviewServer
  11 from file_system import FileNotFoundError
  12 from redirector import Redirector
  13 from servlet import Servlet, Response
  14 from special_paths import SITE_VERIFICATION_FILE
  15 from third_party.handlebar import Handlebar
  16
  17
  18 def _MakeHeaders(content_type):
  19   return {
  20     'X-Frame-Options': 'sameorigin',
  21     'Content-Type': content_type,
  22     'Cache-Control': 'max-age=300',
  23   }
  24
  25
  26 class RenderServlet(Servlet):
  27   '''Servlet which renders templates.
  28   '''
  29
  30   class Delegate(object):
  31     def CreateServerInstance(self):
  32       raise NotImplementedError(self.__class__)
  33
  34   def __init__(self, request, delegate):
  35     Servlet.__init__(self, request)
  36     self._delegate = delegate
  37
  38   def Get(self):
  39     ''' Render the page for a request.
  40     '''
  41     path = self._request.path.lstrip('/')
  42
  43     # The server used to be partitioned based on Chrome channel, but it isn't
  44     # anymore. Redirect from the old state.
  45     channel_name, path = BranchUtility.SplitChannelNameFromPath(path)
  46     if channel_name is not None:
  47       return Response.Redirect('/' + path, permanent=True)
  48
  49     server_instance = self._delegate.CreateServerInstance()
  50
  51     try:
  52       return self._GetSuccessResponse(path, server_instance)
  53     except FileNotFoundError:
  54       # Find the closest 404.html file and serve that, e.g. if the path is
  55       # extensions/manifest/typo.html then first look for
  56       # extensions/manifest/404.html, then extensions/404.html, then 404.html.
  57       #
  58       # Failing that just print 'Not Found' but that should preferrably never
  59       # happen, because it would look really bad.
  60       path_components = path.split('/')
  61       for i in xrange(len(path_components) - 1, -1, -1):
  62         try:
  63           path_404 = posixpath.join(*(path_components[0:i] + ['404']))
  64           response = self._GetSuccessResponse(path_404, server_instance)
  65           if response.status != 200:
  66             continue
  67           return Response.NotFound(response.content.ToString(),
  68                                    headers=response.headers)
  69         except FileNotFoundError: continue
  70       logging.warning('No 404.html found in %s' % path)
  71       return Response.NotFound('Not Found', headers=_MakeHeaders('text/plain'))
  72
  73   def _GetSuccessResponse(self, path, server_instance):
  74     '''Returns the Response from trying to render |path| with
  75     |server_instance|.  If |path| isn't found then a FileNotFoundError will be
  76     raised, such that the only responses that will be returned from this method
  77     are Ok and Redirect.
  78     '''
  79     content_provider, serve_from, path = (
  80         server_instance.content_providers.GetByServeFrom(path))
  81     assert content_provider, 'No ContentProvider found for %s' % path
  82
  83     redirect = Redirector(
  84         server_instance.compiled_fs_factory,
  85         content_provider.file_system).Redirect(self._request.host, path)
  86     if redirect is not None:
  87       return Response.Redirect(redirect, permanent=False)
  88
  89     canonical_path = content_provider.GetCanonicalPath(path)
  90     if canonical_path != path:
  91       redirect_path = posixpath.join(serve_from, canonical_path)
  92       return Response.Redirect('/' + redirect_path, permanent=False)
  93
  94     content_and_type = content_provider.GetContentAndType(path).Get()
  95     if not content_and_type.content:
  96       logging.error('%s had empty content' % path)
  97
  98     content = content_and_type.content
  99     if isinstance(content, Handlebar):
 100       template_content, template_warnings = (
 101           server_instance.template_renderer.Render(content, self._request))
 102       # HACK: the site verification file (google2ed...) doesn't have a title.
 103       content, doc_warnings = server_instance.document_renderer.Render(
 104           template_content,
 105           path,
 106           render_title=path != SITE_VERIFICATION_FILE)
 107       warnings = template_warnings + doc_warnings
 108       if warnings:
 109         sep = '\n - '
 110         logging.warning('Rendering %s:%s%s' % (path, sep, sep.join(warnings)))
 111
 112     content_type = content_and_type.content_type
 113     if isinstance(content, unicode):
 114       content = content.encode('utf-8')
 115       content_type += '; charset=utf-8'
 116
 117     return Response.Ok(content, headers=_MakeHeaders(content_type))