docutils/docutils/parsers/__init__.py

   1 # $Id$
   2 # Author: David Goodger <goodger@python.org>
   3 # Copyright: This module has been placed in the public domain.
   4
   5 """
   6 This package contains Docutils parser modules.
   7 """
   8
   9 __docformat__ = 'reStructuredText'
  10
  11 import sys
  12 from importlib import import_module
  13
  14 from docutils import Component, frontend
  15
  16
  17 class Parser(Component):
  18     settings_spec = (
  19         'Generic Parser Options',
  20         None,
  21         (('Disable directives that insert the contents of an external file; '
  22           'replaced with a "warning" system message.',
  23           ['--no-file-insertion'],
  24           {'action': 'store_false', 'default': 1,
  25            'dest': 'file_insertion_enabled',
  26            'validator': frontend.validate_boolean}),
  27          ('Enable directives that insert the contents '
  28           'of an external file. (default)',
  29           ['--file-insertion-enabled'],
  30           {'action': 'store_true'}),
  31          ('Disable the "raw" directive; '
  32           'replaced with a "warning" system message.',
  33           ['--no-raw'],
  34           {'action': 'store_false', 'default': 1, 'dest': 'raw_enabled',
  35            'validator': frontend.validate_boolean}),
  36          ('Enable the "raw" directive. (default)',
  37           ['--raw-enabled'],
  38           {'action': 'store_true'}),
  39          ('Maximal number of characters in an input line. Default 10 000.',
  40           ['--line-length-limit'],
  41           {'metavar': '<length>', 'type': 'int', 'default': 10000,
  42            'validator': frontend.validate_nonnegative_int}),
  43         ))
  44     component_type = 'parser'
  45     config_section = 'parsers'
  46
  47     def parse(self, inputstring, document):
  48         """Override to parse `inputstring` into document tree `document`."""
  49         raise NotImplementedError('subclass must override this method')
  50
  51     def setup_parse(self, inputstring, document):
  52         """Initial parse setup.  Call at start of `self.parse()`."""
  53         self.inputstring = inputstring
  54         # provide fallbacks in case the document has only generic settings
  55         document.settings.setdefault('file_insertion_enabled', False)
  56         document.settings.setdefault('raw_enabled', False)
  57         document.settings.setdefault('line_length_limit', 10000)
  58         self.document = document
  59         document.reporter.attach_observer(document.note_parse_message)
  60
  61     def finish_parse(self):
  62         """Finalize parse details.  Call at end of `self.parse()`."""
  63         self.document.reporter.detach_observer(
  64             self.document.note_parse_message)
  65
  66
  67 _parser_aliases = {
  68       'restructuredtext': 'rst',
  69       'rest': 'rst',
  70       'restx': 'rst',
  71       'rtxt': 'rst',
  72       'recommonmark': 'recommonmark_wrapper',
  73       'commonmark': 'recommonmark_wrapper',
  74       'markdown': 'recommonmark_wrapper'}
  75
  76 def get_parser_class(parser_name):
  77     """Return the Parser class from the `parser_name` module."""
  78     parser_name = parser_name.lower()
  79     if parser_name in _parser_aliases:
  80         parser_name = _parser_aliases[parser_name]
  81     try:
  82         module = import_module('docutils.parsers.'+parser_name)
  83     except ImportError:
  84         module = import_module(parser_name)
  85     return module.Parser