chrome/common/extensions/docs/server2/document_renderer.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 os
   7 from document_parser import ParseDocument
   8 from platform_util import ExtractPlatformFromURL
   9 from third_party.json_schema_compiler.model import UnixName
  10
  11
  12 class DocumentRenderer(object):
  13   '''Performs document-level rendering such as the title, references,
  14   and table of contents: pulling that data out of the document, then
  15   replacing the $(title), $(ref:...) and $(table_of_contents) tokens with them.
  16
  17   This can be thought of as a parallel to TemplateRenderer; while
  18   TemplateRenderer is responsible for interpreting templates and rendering files
  19   within the template engine, DocumentRenderer is responsible for interpreting
  20   higher-level document concepts like the title and TOC, then performing string
  21   replacement for them. The syntax for this replacement is $(...) where ... is
  22   the concept. Currently title and table_of_contents are supported.
  23   '''
  24
  25   def __init__(self, table_of_contents_renderer, platform_bundle):
  26     self._table_of_contents_renderer = table_of_contents_renderer
  27     self._platform_bundle = platform_bundle
  28
  29   def _RenderLinks(self, document, path):
  30     ''' Replaces all $(ref:...) references in |document| with html links.
  31
  32         References have two forms:
  33
  34           $(ref:api.node) - Replaces the reference with a link to node on the
  35                             API page. The title is set to the name of the node.
  36
  37           $(ref:api.node Title) - Same as the previous form, but title is set
  38                                   to "Title".
  39     '''
  40     START_REF = '$(ref:'
  41     END_REF = ')'
  42     MAX_REF_LENGTH = 256
  43
  44     new_document = []
  45
  46     # Keeps track of position within |document|
  47     cursor_index = 0
  48     start_ref_index = document.find(START_REF)
  49
  50     while start_ref_index != -1:
  51       end_ref_index = document.find(END_REF, start_ref_index)
  52
  53       if (end_ref_index == -1 or
  54           end_ref_index - start_ref_index > MAX_REF_LENGTH):
  55         end_ref_index = document.find(' ', start_ref_index)
  56         logging.error('%s:%s has no terminating ) at line %s' % (
  57             path,
  58             document[start_ref_index:end_ref_index],
  59             document.count('\n', 0, end_ref_index)))
  60
  61         new_document.append(document[cursor_index:end_ref_index + 1])
  62       else:
  63         ref = document[start_ref_index:end_ref_index]
  64         ref_parts = ref[len(START_REF):].split(None, 1)
  65
  66         # Guess the api name from the html name, replacing '_' with '.' (e.g.
  67         # if the page is app_window.html, guess the api name is app.window)
  68         api_name = os.path.splitext(os.path.basename(path))[0].replace('_', '.')
  69         title = ref_parts[0] if len(ref_parts) == 1 else ref_parts[1]
  70
  71         platform = ExtractPlatformFromURL(path)
  72         if platform is None:
  73           logging.error('Cannot resolve reference without a platform.')
  74           continue
  75         ref_dict = self._platform_bundle.GetReferenceResolver(
  76             platform).SafeGetLink(ref_parts[0],
  77                                   namespace=api_name,
  78                                   title=title,
  79                                   path=path)
  80
  81         new_document.append(document[cursor_index:start_ref_index])
  82         new_document.append('<a href=%s/%s>%s</a>' % (
  83             self._platform_bundle._base_path + platform,
  84             ref_dict['href'],
  85             ref_dict['text']))
  86
  87       cursor_index = end_ref_index + 1
  88       start_ref_index = document.find(START_REF, cursor_index)
  89
  90     new_document.append(document[cursor_index:])
  91
  92     return ''.join(new_document)
  93
  94   def Render(self, document, path, render_title=False):
  95     ''' |document|: document to be rendered.
  96             |path|: request path to the document.
  97     |render_title|: boolean representing whether or not to render a title.
  98     '''
  99     # Render links first so that parsing and later replacements aren't
 100     # affected by $(ref...) substitutions
 101     document = self._RenderLinks(document, path)
 102
 103     parsed_document = ParseDocument(document, expect_title=render_title)
 104     toc_text, toc_warnings = self._table_of_contents_renderer.Render(
 105         parsed_document.sections)
 106
 107     # Only 1 title and 1 table of contents substitution allowed; in the common
 108     # case, save necessarily running over the entire file.
 109     if parsed_document.title:
 110       document = document.replace('$(title)', parsed_document.title, 1)
 111     return (document.replace('$(table_of_contents)', toc_text, 1),
 112             parsed_document.warnings + toc_warnings)