docutils/frontend.py

   1 # $Id$
   2 # Author: David Goodger <goodger@python.org>
   3 # Copyright: This module has been placed in the public domain.
   4
   5 """
   6 Command-line and common processing for Docutils front-end tools.
   7
   8 Exports the following classes:
   9
  10 * `OptionParser`: Standard Docutils command-line processing.
  11 * `Option`: Customized version of `optparse.Option`; validation support.
  12 * `Values`: Runtime settings; objects are simple structs
  13   (``object.attribute``).  Supports cumulative list settings (attributes).
  14 * `ConfigParser`: Standard Docutils config file processing.
  15
  16 Also exports the following functions:
  17
  18 * Option callbacks: `store_multiple`, `read_config_file`.
  19 * Setting validators: `validate_encoding`,
  20   `validate_encoding_error_handler`,
  21   `validate_encoding_and_error_handler`,
  22   `validate_boolean`, `validate_ternary`, `validate_threshold`,
  23   `validate_colon_separated_string_list`,
  24   `validate_comma_separated_string_list`,
  25   `validate_dependency_file`.
  26 * `make_paths_absolute`.
  27 * SettingSpec manipulation: `filter_settings_spec`.
  28 """
  29
  30 __docformat__ = 'reStructuredText'
  31
  32 import os
  33 import os.path
  34 import sys
  35 import warnings
  36 import ConfigParser as CP
  37 import codecs
  38 import optparse
  39 from optparse import SUPPRESS_HELP
  40 import docutils
  41 import docutils.utils
  42 import docutils.nodes
  43 from docutils.utils.error_reporting import locale_encoding, ErrorOutput, ErrorString
  44
  45
  46 def store_multiple(option, opt, value, parser, *args, **kwargs):
  47     """
  48     Store multiple values in `parser.values`.  (Option callback.)
  49
  50     Store `None` for each attribute named in `args`, and store the value for
  51     each key (attribute name) in `kwargs`.
  52     """
  53     for attribute in args:
  54         setattr(parser.values, attribute, None)
  55     for key, value in kwargs.items():
  56         setattr(parser.values, key, value)
  57
  58 def read_config_file(option, opt, value, parser):
  59     """
  60     Read a configuration file during option processing.  (Option callback.)
  61     """
  62     try:
  63         new_settings = parser.get_config_file_settings(value)
  64     except ValueError, error:
  65         parser.error(error)
  66     parser.values.update(new_settings, parser)
  67
  68 def validate_encoding(setting, value, option_parser,
  69                       config_parser=None, config_section=None):
  70     try:
  71         codecs.lookup(value)
  72     except LookupError:
  73         raise (LookupError('setting "%s": unknown encoding: "%s"'
  74                            % (setting, value)),
  75                None, sys.exc_info()[2])
  76     return value
  77
  78 def validate_encoding_error_handler(setting, value, option_parser,
  79                                     config_parser=None, config_section=None):
  80     try:
  81         codecs.lookup_error(value)
  82     except LookupError:
  83         raise (LookupError(
  84             'unknown encoding error handler: "%s" (choices: '
  85             '"strict", "ignore", "replace", "backslashreplace", '
  86             '"xmlcharrefreplace", and possibly others; see documentation for '
  87             'the Python ``codecs`` module)' % value),
  88                None, sys.exc_info()[2])
  89     return value
  90
  91 def validate_encoding_and_error_handler(
  92     setting, value, option_parser, config_parser=None, config_section=None):
  93     """
  94     Side-effect: if an error handler is included in the value, it is inserted
  95     into the appropriate place as if it was a separate setting/option.
  96     """
  97     if ':' in value:
  98         encoding, handler = value.split(':')
  99         validate_encoding_error_handler(
 100             setting + '_error_handler', handler, option_parser,
 101             config_parser, config_section)
 102         if config_parser:
 103             config_parser.set(config_section, setting + '_error_handler',
 104                               handler)
 105         else:
 106             setattr(option_parser.values, setting + '_error_handler', handler)
 107     else:
 108         encoding = value
 109     validate_encoding(setting, encoding, option_parser,
 110                       config_parser, config_section)
 111     return encoding
 112
 113 def validate_boolean(setting, value, option_parser,
 114                      config_parser=None, config_section=None):
 115     """Check/normalize boolean settings:
 116          True:  '1', 'on', 'yes', 'true'
 117          False: '0', 'off', 'no','false', ''
 118     """
 119     if isinstance(value, bool):
 120         return value
 121     try:
 122         return option_parser.booleans[value.strip().lower()]
 123     except KeyError:
 124         raise (LookupError('unknown boolean value: "%s"' % value),
 125                None, sys.exc_info()[2])
 126
 127 def validate_ternary(setting, value, option_parser,
 128                      config_parser=None, config_section=None):
 129     """Check/normalize three-value settings:
 130          True:  '1', 'on', 'yes', 'true'
 131          False: '0', 'off', 'no','false', ''
 132          any other value: returned as-is.
 133     """
 134     if isinstance(value, bool) or value is None:
 135         return value
 136     try:
 137         return option_parser.booleans[value.strip().lower()]
 138     except KeyError:
 139         return value
 140
 141 def validate_nonnegative_int(setting, value, option_parser,
 142                              config_parser=None, config_section=None):
 143     value = int(value)
 144     if value < 0:
 145         raise ValueError('negative value; must be positive or zero')
 146     return value
 147
 148 def validate_threshold(setting, value, option_parser,
 149                        config_parser=None, config_section=None):
 150     try:
 151         return int(value)
 152     except ValueError:
 153         try:
 154             return option_parser.thresholds[value.lower()]
 155         except (KeyError, AttributeError):
 156             raise (LookupError('unknown threshold: %r.' % value),
 157                    None, sys.exc_info[2])
 158
 159 def validate_colon_separated_string_list(
 160     setting, value, option_parser, config_parser=None, config_section=None):
 161     if isinstance(value, unicode):
 162         value = value.split(':')
 163     else:
 164         last = value.pop()
 165         value.extend(last.split(':'))
 166     return value
 167
 168 def validate_comma_separated_list(setting, value, option_parser,
 169                                     config_parser=None, config_section=None):
 170     """Check/normalize list arguments (split at "," and strip whitespace).
 171     """
 172     # `value` is already a list when  given as command line option
 173     # and "action" is "append"
 174     # in python2 buildhtml.py calls this once with str after several
 175     #   times with unicode. MAYBE fix somewhere else.
 176     #if isinstance(value, unicode): #py3
 177     #if isinstance(value, basestr): # py3 and py2.7
 178     if not hasattr(value, 'pop'):
 179         value = [value]
 180     # this function is called for every option added to `value`
 181     # -> split the last item and append the result:
 182     last = value.pop()
 183     classes = [cls.strip(u' \t\n') for cls in last.split(',')
 184                if cls.strip(u' \t\n')]
 185     value.extend(classes)
 186     return value
 187
 188 def validate_url_trailing_slash(
 189     setting, value, option_parser, config_parser=None, config_section=None):
 190     if not value:
 191         return './'
 192     elif value.endswith('/'):
 193         return value
 194     else:
 195         return value + '/'
 196
 197 def validate_dependency_file(setting, value, option_parser,
 198                              config_parser=None, config_section=None):
 199     try:
 200         return docutils.utils.DependencyList(value)
 201     except IOError:
 202         return docutils.utils.DependencyList(None)
 203
 204 def validate_strip_class(setting, value, option_parser,
 205                          config_parser=None, config_section=None):
 206     # value is a comma separated string list:
 207     value = validate_comma_separated_list(setting, value, option_parser,
 208                                           config_parser, config_section)
 209     # validate list elements:
 210     for cls in value:
 211         normalized = docutils.nodes.make_id(cls)
 212         if cls != normalized:
 213             raise ValueError('invalid class value %r (perhaps %r?)'
 214                              % (cls, normalized))
 215     return value
 216
 217 def make_paths_absolute(pathdict, keys, base_path=None):
 218     """
 219     Interpret filesystem path settings relative to the `base_path` given.
 220
 221     Paths are values in `pathdict` whose keys are in `keys`.  Get `keys` from
 222     `OptionParser.relative_path_settings`.
 223     """
 224     if base_path is None:
 225         base_path = os.getcwdu() # type(base_path) == unicode
 226         # to allow combining non-ASCII cwd with unicode values in `pathdict`
 227     for key in keys:
 228         if key in pathdict:
 229             value = pathdict[key]
 230             if isinstance(value, list):
 231                 value = [make_one_path_absolute(base_path, path)
 232                          for path in value]
 233             elif value:
 234                 value = make_one_path_absolute(base_path, value)
 235             pathdict[key] = value
 236
 237 def make_one_path_absolute(base_path, path):
 238     return os.path.abspath(os.path.join(base_path, path))
 239
 240 def filter_settings_spec(settings_spec, *exclude, **replace):
 241     """Return a copy of `settings_spec` excluding/replacing some settings.
 242
 243     `settings_spec` is a tuple of configuration settings with a structure
 244     described for docutils.SettingsSpec.settings_spec.
 245
 246     Optional positional arguments are names of to-be-excluded settings.
 247     Keyword arguments are option specification replacements.
 248     (See the html4strict writer for an example.)
 249     """
 250     settings = list(settings_spec)
 251     # every third item is a sequence of option tuples
 252     for i in range(2, len(settings), 3):
 253         newopts = []
 254         for opt_spec in settings[i]:
 255             # opt_spec is ("<help>", [<option strings>], {<keyword args>})
 256             opt_name = [opt_string[2:].replace('-', '_')
 257                         for opt_string in opt_spec[1]
 258                             if opt_string.startswith('--')
 259                        ][0]
 260             if opt_name in exclude:
 261                 continue
 262             if opt_name in replace.keys():
 263                 newopts.append(replace[opt_name])
 264             else:
 265                 newopts.append(opt_spec)
 266         settings[i] = tuple(newopts)
 267     return tuple(settings)
 268
 269
 270 class Values(optparse.Values):
 271
 272     """
 273     Updates list attributes by extension rather than by replacement.
 274     Works in conjunction with the `OptionParser.lists` instance attribute.
 275     """
 276
 277     def __init__(self, *args, **kwargs):
 278         optparse.Values.__init__(self, *args, **kwargs)
 279         if (not hasattr(self, 'record_dependencies')
 280             or self.record_dependencies is None):
 281             # Set up dependency list, in case it is needed.
 282             self.record_dependencies = docutils.utils.DependencyList()
 283
 284     def update(self, other_dict, option_parser):
 285         if isinstance(other_dict, Values):
 286             other_dict = other_dict.__dict__
 287         other_dict = other_dict.copy()
 288         for setting in option_parser.lists.keys():
 289             if (hasattr(self, setting) and setting in other_dict):
 290                 value = getattr(self, setting)
 291                 if value:
 292                     value += other_dict[setting]
 293                     del other_dict[setting]
 294         self._update_loose(other_dict)
 295
 296     def copy(self):
 297         """Return a shallow copy of `self`."""
 298         return self.__class__(defaults=self.__dict__)
 299
 300
 301 class Option(optparse.Option):
 302
 303     ATTRS = optparse.Option.ATTRS + ['validator', 'overrides']
 304
 305     def process(self, opt, value, values, parser):
 306         """
 307         Call the validator function on applicable settings and
 308         evaluate the 'overrides' option.
 309         Extends `optparse.Option.process`.
 310         """
 311         result = optparse.Option.process(self, opt, value, values, parser)
 312         setting = self.dest
 313         if setting:
 314             if self.validator:
 315                 value = getattr(values, setting)
 316                 try:
 317                     new_value = self.validator(setting, value, parser)
 318                 except Exception, error:
 319                     raise (optparse.OptionValueError(
 320                         'Error in option "%s":\n    %s'
 321                         % (opt, ErrorString(error))),
 322                            None, sys.exc_info()[2])
 323                 setattr(values, setting, new_value)
 324             if self.overrides:
 325                 setattr(values, self.overrides, None)
 326         return result
 327
 328
 329 class OptionParser(optparse.OptionParser, docutils.SettingsSpec):
 330
 331     """
 332     Parser for command-line and library use.  The `settings_spec`
 333     specification here and in other Docutils components are merged to build
 334     the set of command-line options and runtime settings for this process.
 335
 336     Common settings (defined below) and component-specific settings must not
 337     conflict.  Short options are reserved for common settings, and components
 338     are restrict to using long options.
 339     """
 340
 341     standard_config_files = [
 342         '/etc/docutils.conf',           # system-wide
 343         './docutils.conf',              # project-specific
 344         '~/.docutils']                  # user-specific
 345     """Docutils configuration files, using ConfigParser syntax.  Filenames
 346     will be tilde-expanded later.  Later files override earlier ones."""
 347
 348     threshold_choices = 'info 1 warning 2 error 3 severe 4 none 5'.split()
 349     """Possible inputs for for --report and --halt threshold values."""
 350
 351     thresholds = {'info': 1, 'warning': 2, 'error': 3, 'severe': 4, 'none': 5}
 352     """Lookup table for --report and --halt threshold values."""
 353
 354     booleans={'1': True, 'on': True, 'yes': True, 'true': True,
 355               '0': False, 'off': False, 'no': False, 'false': False, '': False}
 356     """Lookup table for boolean configuration file settings."""
 357
 358     default_error_encoding = getattr(sys.stderr, 'encoding',
 359                                      None) or locale_encoding or 'ascii'
 360
 361     default_error_encoding_error_handler = 'backslashreplace'
 362
 363     settings_spec = (
 364         'General Docutils Options',
 365         None,
 366         (('Specify the document title as metadata.',
 367           ['--title'], {}),
 368          ('Include a "Generated by Docutils" credit and link.',
 369           ['--generator', '-g'], {'action': 'store_true',
 370                                   'validator': validate_boolean}),
 371          ('Do not include a generator credit.',
 372           ['--no-generator'], {'action': 'store_false', 'dest': 'generator'}),
 373          ('Include the date at the end of the document (UTC).',
 374           ['--date', '-d'], {'action': 'store_const', 'const': '%Y-%m-%d',
 375                              'dest': 'datestamp'}),
 376          ('Include the time & date (UTC).',
 377           ['--time', '-t'], {'action': 'store_const',
 378                              'const': '%Y-%m-%d %H:%M UTC',
 379                              'dest': 'datestamp'}),
 380          ('Do not include a datestamp of any kind.',
 381           ['--no-datestamp'], {'action': 'store_const', 'const': None,
 382                                'dest': 'datestamp'}),
 383          ('Include a "View document source" link.',
 384           ['--source-link', '-s'], {'action': 'store_true',
 385                                     'validator': validate_boolean}),
 386          ('Use <URL> for a source link; implies --source-link.',
 387           ['--source-url'], {'metavar': '<URL>'}),
 388          ('Do not include a "View document source" link.',
 389           ['--no-source-link'],
 390           {'action': 'callback', 'callback': store_multiple,
 391            'callback_args': ('source_link', 'source_url')}),
 392          ('Link from section headers to TOC entries.  (default)',
 393           ['--toc-entry-backlinks'],
 394           {'dest': 'toc_backlinks', 'action': 'store_const', 'const': 'entry',
 395            'default': 'entry'}),
 396          ('Link from section headers to the top of the TOC.',
 397           ['--toc-top-backlinks'],
 398           {'dest': 'toc_backlinks', 'action': 'store_const', 'const': 'top'}),
 399          ('Disable backlinks to the table of contents.',
 400           ['--no-toc-backlinks'],
 401           {'dest': 'toc_backlinks', 'action': 'store_false'}),
 402          ('Link from footnotes/citations to references. (default)',
 403           ['--footnote-backlinks'],
 404           {'action': 'store_true', 'default': 1,
 405            'validator': validate_boolean}),
 406          ('Disable backlinks from footnotes and citations.',
 407           ['--no-footnote-backlinks'],
 408           {'dest': 'footnote_backlinks', 'action': 'store_false'}),
 409          ('Enable section numbering by Docutils.  (default)',
 410           ['--section-numbering'],
 411           {'action': 'store_true', 'dest': 'sectnum_xform',
 412            'default': 1, 'validator': validate_boolean}),
 413          ('Disable section numbering by Docutils.',
 414           ['--no-section-numbering'],
 415           {'action': 'store_false', 'dest': 'sectnum_xform'}),
 416          ('Remove comment elements from the document tree.',
 417           ['--strip-comments'],
 418           {'action': 'store_true', 'validator': validate_boolean}),
 419          ('Leave comment elements in the document tree. (default)',
 420           ['--leave-comments'],
 421           {'action': 'store_false', 'dest': 'strip_comments'}),
 422          ('Remove all elements with classes="<class>" from the document tree. '
 423           'Warning: potentially dangerous; use with caution. '
 424           '(Multiple-use option.)',
 425           ['--strip-elements-with-class'],
 426           {'action': 'append', 'dest': 'strip_elements_with_classes',
 427            'metavar': '<class>', 'validator': validate_strip_class}),
 428          ('Remove all classes="<class>" attributes from elements in the '
 429           'document tree. Warning: potentially dangerous; use with caution. '
 430           '(Multiple-use option.)',
 431           ['--strip-class'],
 432           {'action': 'append', 'dest': 'strip_classes',
 433            'metavar': '<class>', 'validator': validate_strip_class}),
 434          ('Report system messages at or higher than <level>: "info" or "1", '
 435           '"warning"/"2" (default), "error"/"3", "severe"/"4", "none"/"5"',
 436           ['--report', '-r'], {'choices': threshold_choices, 'default': 2,
 437                                'dest': 'report_level', 'metavar': '<level>',
 438                                'validator': validate_threshold}),
 439          ('Report all system messages.  (Same as "--report=1".)',
 440           ['--verbose', '-v'], {'action': 'store_const', 'const': 1,
 441                                 'dest': 'report_level'}),
 442          ('Report no system messages.  (Same as "--report=5".)',
 443           ['--quiet', '-q'], {'action': 'store_const', 'const': 5,
 444                               'dest': 'report_level'}),
 445          ('Halt execution at system messages at or above <level>.  '
 446           'Levels as in --report.  Default: 4 (severe).',
 447           ['--halt'], {'choices': threshold_choices, 'dest': 'halt_level',
 448                        'default': 4, 'metavar': '<level>',
 449                        'validator': validate_threshold}),
 450          ('Halt at the slightest problem.  Same as "--halt=info".',
 451           ['--strict'], {'action': 'store_const', 'const': 1,
 452                          'dest': 'halt_level'}),
 453          ('Enable a non-zero exit status for non-halting system messages at '
 454           'or above <level>.  Default: 5 (disabled).',
 455           ['--exit-status'], {'choices': threshold_choices,
 456                               'dest': 'exit_status_level',
 457                               'default': 5, 'metavar': '<level>',
 458                               'validator': validate_threshold}),
 459          ('Enable debug-level system messages and diagnostics.',
 460           ['--debug'], {'action': 'store_true', 'validator': validate_boolean}),
 461          ('Disable debug output.  (default)',
 462           ['--no-debug'], {'action': 'store_false', 'dest': 'debug'}),
 463          ('Send the output of system messages to <file>.',
 464           ['--warnings'], {'dest': 'warning_stream', 'metavar': '<file>'}),
 465          ('Enable Python tracebacks when Docutils is halted.',
 466           ['--traceback'], {'action': 'store_true', 'default': None,
 467                             'validator': validate_boolean}),
 468          ('Disable Python tracebacks.  (default)',
 469           ['--no-traceback'], {'dest': 'traceback', 'action': 'store_false'}),
 470          ('Specify the encoding and optionally the '
 471           'error handler of input text.  Default: <locale-dependent>:strict.',
 472           ['--input-encoding', '-i'],
 473           {'metavar': '<name[:handler]>',
 474            'validator': validate_encoding_and_error_handler}),
 475          ('Specify the error handler for undecodable characters.  '
 476           'Choices: "strict" (default), "ignore", and "replace".',
 477           ['--input-encoding-error-handler'],
 478           {'default': 'strict', 'validator': validate_encoding_error_handler}),
 479          ('Specify the text encoding and optionally the error handler for '
 480           'output.  Default: UTF-8:strict.',
 481           ['--output-encoding', '-o'],
 482           {'metavar': '<name[:handler]>', 'default': 'utf-8',
 483            'validator': validate_encoding_and_error_handler}),
 484          ('Specify error handler for unencodable output characters; '
 485           '"strict" (default), "ignore", "replace", '
 486           '"xmlcharrefreplace", "backslashreplace".',
 487           ['--output-encoding-error-handler'],
 488           {'default': 'strict', 'validator': validate_encoding_error_handler}),
 489          ('Specify text encoding and error handler for error output.  '
 490           'Default: %s:%s.'
 491           % (default_error_encoding, default_error_encoding_error_handler),
 492           ['--error-encoding', '-e'],
 493           {'metavar': '<name[:handler]>', 'default': default_error_encoding,
 494            'validator': validate_encoding_and_error_handler}),
 495          ('Specify the error handler for unencodable characters in '
 496           'error output.  Default: %s.'
 497           % default_error_encoding_error_handler,
 498           ['--error-encoding-error-handler'],
 499           {'default': default_error_encoding_error_handler,
 500            'validator': validate_encoding_error_handler}),
 501          ('Specify the language (as BCP 47 language tag).  Default: en.',
 502           ['--language', '-l'], {'dest': 'language_code', 'default': 'en',
 503                                  'metavar': '<name>'}),
 504          ('Write output file dependencies to <file>.',
 505           ['--record-dependencies'],
 506           {'metavar': '<file>', 'validator': validate_dependency_file,
 507            'default': None}),           # default set in Values class
 508          ('Read configuration settings from <file>, if it exists.',
 509           ['--config'], {'metavar': '<file>', 'type': 'string',
 510                          'action': 'callback', 'callback': read_config_file}),
 511          ("Show this program's version number and exit.",
 512           ['--version', '-V'], {'action': 'version'}),
 513          ('Show this help message and exit.',
 514           ['--help', '-h'], {'action': 'help'}),
 515          # Typically not useful for non-programmatical use:
 516          (SUPPRESS_HELP, ['--id-prefix'], {'default': ''}),
 517          (SUPPRESS_HELP, ['--auto-id-prefix'], {'default': 'id'}),
 518          # Hidden options, for development use only:
 519          (SUPPRESS_HELP, ['--dump-settings'], {'action': 'store_true'}),
 520          (SUPPRESS_HELP, ['--dump-internals'], {'action': 'store_true'}),
 521          (SUPPRESS_HELP, ['--dump-transforms'], {'action': 'store_true'}),
 522          (SUPPRESS_HELP, ['--dump-pseudo-xml'], {'action': 'store_true'}),
 523          (SUPPRESS_HELP, ['--expose-internal-attribute'],
 524           {'action': 'append', 'dest': 'expose_internals',
 525            'validator': validate_colon_separated_string_list}),
 526          (SUPPRESS_HELP, ['--strict-visitor'], {'action': 'store_true'}),
 527          ))
 528     """Runtime settings and command-line options common to all Docutils front
 529     ends.  Setting specs specific to individual Docutils components are also
 530     used (see `populate_from_components()`)."""
 531
 532     settings_defaults = {'_disable_config': None,
 533                          '_source': None,
 534                          '_destination': None,
 535                          '_config_files': None}
 536     """Defaults for settings that don't have command-line option equivalents."""
 537
 538     relative_path_settings = ('warning_stream',)
 539
 540     config_section = 'general'
 541
 542     version_template = ('%%prog (Docutils %s [%s], Python %s, on %s)'
 543                         % (docutils.__version__, docutils.__version_details__,
 544                            sys.version.split()[0], sys.platform))
 545     """Default version message."""
 546
 547     def __init__(self, components=(), defaults=None, read_config_files=None,
 548                  *args, **kwargs):
 549         """
 550         `components` is a list of Docutils components each containing a
 551         ``.settings_spec`` attribute.  `defaults` is a mapping of setting
 552         default overrides.
 553         """
 554
 555         self.lists = {}
 556         """Set of list-type settings."""
 557
 558         self.config_files = []
 559         """List of paths of applied configuration files."""
 560
 561         optparse.OptionParser.__init__(
 562             self, option_class=Option, add_help_option=None,
 563             formatter=optparse.TitledHelpFormatter(width=78),
 564             *args, **kwargs)
 565         if not self.version:
 566             self.version = self.version_template
 567         # Make an instance copy (it will be modified):
 568         self.relative_path_settings = list(self.relative_path_settings)
 569         self.components = (self,) + tuple(components)
 570         self.populate_from_components(self.components)
 571         self.set_defaults_from_dict(defaults or {})
 572         if read_config_files and not self.defaults['_disable_config']:
 573             try:
 574                 config_settings = self.get_standard_config_settings()
 575             except ValueError, error:
 576                 self.error(error)
 577             self.set_defaults_from_dict(config_settings.__dict__)
 578
 579     def populate_from_components(self, components):
 580         """
 581         For each component, first populate from the `SettingsSpec.settings_spec`
 582         structure, then from the `SettingsSpec.settings_defaults` dictionary.
 583         After all components have been processed, check for and populate from
 584         each component's `SettingsSpec.settings_default_overrides` dictionary.
 585         """
 586         for component in components:
 587             if component is None:
 588                 continue
 589             settings_spec = component.settings_spec
 590             self.relative_path_settings.extend(
 591                 component.relative_path_settings)
 592             for i in range(0, len(settings_spec), 3):
 593                 title, description, option_spec = settings_spec[i:i+3]
 594                 if title:
 595                     group = optparse.OptionGroup(self, title, description)
 596                     self.add_option_group(group)
 597                 else:
 598                     group = self        # single options
 599                 for (help_text, option_strings, kwargs) in option_spec:
 600                     option = group.add_option(help=help_text, *option_strings,
 601                                               **kwargs)
 602                     if kwargs.get('action') == 'append':
 603                         self.lists[option.dest] = 1
 604                 if component.settings_defaults:
 605                     self.defaults.update(component.settings_defaults)
 606         for component in components:
 607             if component and component.settings_default_overrides:
 608                 self.defaults.update(component.settings_default_overrides)
 609
 610     def get_standard_config_files(self):
 611         """Return list of config files, from environment or standard."""
 612         try:
 613             config_files = os.environ['DOCUTILSCONFIG'].split(os.pathsep)
 614         except KeyError:
 615             config_files = self.standard_config_files
 616
 617         # If 'HOME' is not set, expandvars() requires the 'pwd' module which is
 618         # not available under certain environments, for example, within
 619         # mod_python.  The publisher ends up in here, and we need to publish
 620         # from within mod_python.  Therefore we need to avoid expanding when we
 621         # are in those environments.
 622         expand = os.path.expanduser
 623         if 'HOME' not in os.environ:
 624             try:
 625                 import pwd
 626             except ImportError:
 627                 expand = lambda x: x
 628         return [expand(f) for f in config_files if f.strip()]
 629
 630     def get_standard_config_settings(self):
 631         settings = Values()
 632         for filename in self.get_standard_config_files():
 633             settings.update(self.get_config_file_settings(filename), self)
 634         return settings
 635
 636     def get_config_file_settings(self, config_file):
 637         """Returns a dictionary containing appropriate config file settings."""
 638         parser = ConfigParser()
 639         parser.read(config_file, self)
 640         self.config_files.extend(parser._files)
 641         base_path = os.path.dirname(config_file)
 642         applied = {}
 643         settings = Values()
 644         for component in self.components:
 645             if not component:
 646                 continue
 647             for section in (tuple(component.config_section_dependencies or ())
 648                             + (component.config_section,)):
 649                 if section in applied:
 650                     continue
 651                 applied[section] = 1
 652                 settings.update(parser.get_section(section), self)
 653         make_paths_absolute(
 654             settings.__dict__, self.relative_path_settings, base_path)
 655         return settings.__dict__
 656
 657     def check_values(self, values, args):
 658         """Store positional arguments as runtime settings."""
 659         values._source, values._destination = self.check_args(args)
 660         make_paths_absolute(values.__dict__, self.relative_path_settings)
 661         values._config_files = self.config_files
 662         return values
 663
 664     def check_args(self, args):
 665         source = destination = None
 666         if args:
 667             source = args.pop(0)
 668             if source == '-':           # means stdin
 669                 source = None
 670         if args:
 671             destination = args.pop(0)
 672             if destination == '-':      # means stdout
 673                 destination = None
 674         if args:
 675             self.error('Maximum 2 arguments allowed.')
 676         if source and source == destination:
 677             self.error('Do not specify the same file for both source and '
 678                        'destination.  It will clobber the source file.')
 679         return source, destination
 680
 681     def set_defaults_from_dict(self, defaults):
 682         self.defaults.update(defaults)
 683
 684     def get_default_values(self):
 685         """Needed to get custom `Values` instances."""
 686         defaults = Values(self.defaults)
 687         defaults._config_files = self.config_files
 688         return defaults
 689
 690     def get_option_by_dest(self, dest):
 691         """
 692         Get an option by its dest.
 693
 694         If you're supplying a dest which is shared by several options,
 695         it is undefined which option of those is returned.
 696
 697         A KeyError is raised if there is no option with the supplied
 698         dest.
 699         """
 700         for group in self.option_groups + [self]:
 701             for option in group.option_list:
 702                 if option.dest == dest:
 703                     return option
 704         raise KeyError('No option with dest == %r.' % dest)
 705
 706
 707 class ConfigParser(CP.RawConfigParser):
 708
 709     old_settings = {
 710         'pep_stylesheet': ('pep_html writer', 'stylesheet'),
 711         'pep_stylesheet_path': ('pep_html writer', 'stylesheet_path'),
 712         'pep_template': ('pep_html writer', 'template')}
 713     """{old setting: (new section, new setting)} mapping, used by
 714     `handle_old_config`, to convert settings from the old [options] section."""
 715
 716     old_warning = """
 717 The "[option]" section is deprecated.  Support for old-format configuration
 718 files may be removed in a future Docutils release.  Please revise your
 719 configuration files.  See <http://docutils.sf.net/docs/user/config.html>,
 720 section "Old-Format Configuration Files".
 721 """
 722
 723     not_utf8_error = """\
 724 Unable to read configuration file "%s": content not encoded as UTF-8.
 725 Skipping "%s" configuration file.
 726 """
 727
 728     def __init__(self, *args, **kwargs):
 729         CP.RawConfigParser.__init__(self, *args, **kwargs)
 730
 731         self._files = []
 732         """List of paths of configuration files read."""
 733
 734         self._stderr = ErrorOutput()
 735         """Wrapper around sys.stderr catching en-/decoding errors"""
 736
 737     def read(self, filenames, option_parser):
 738         if type(filenames) in (str, unicode):
 739             filenames = [filenames]
 740         for filename in filenames:
 741             try:
 742                 # Config files must be UTF-8-encoded:
 743                 fp = codecs.open(filename, 'r', 'utf-8')
 744             except IOError:
 745                 continue
 746             try:
 747                 if sys.version_info < (3,2):
 748                     CP.RawConfigParser.readfp(self, fp, filename)
 749                 else:
 750                     CP.RawConfigParser.read_file(self, fp, filename)
 751             except UnicodeDecodeError:
 752                 self._stderr.write(self.not_utf8_error % (filename, filename))
 753                 fp.close()
 754                 continue
 755             fp.close()
 756             self._files.append(filename)
 757             if self.has_section('options'):
 758                 self.handle_old_config(filename)
 759             self.validate_settings(filename, option_parser)
 760
 761     def handle_old_config(self, filename):
 762         warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
 763                                filename, 0)
 764         options = self.get_section('options')
 765         if not self.has_section('general'):
 766             self.add_section('general')
 767         for key, value in options.items():
 768             if key in self.old_settings:
 769                 section, setting = self.old_settings[key]
 770                 if not self.has_section(section):
 771                     self.add_section(section)
 772             else:
 773                 section = 'general'
 774                 setting = key
 775             if not self.has_option(section, setting):
 776                 self.set(section, setting, value)
 777         self.remove_section('options')
 778
 779     def validate_settings(self, filename, option_parser):
 780         """
 781         Call the validator function and implement overrides on all applicable
 782         settings.
 783         """
 784         for section in self.sections():
 785             for setting in self.options(section):
 786                 try:
 787                     option = option_parser.get_option_by_dest(setting)
 788                 except KeyError:
 789                     continue
 790                 if option.validator:
 791                     value = self.get(section, setting)
 792                     try:
 793                         new_value = option.validator(
 794                             setting, value, option_parser,
 795                             config_parser=self, config_section=section)
 796                     except Exception, error:
 797                         raise (ValueError(
 798                             'Error in config file "%s", section "[%s]":\n'
 799                             '    %s\n'
 800                             '        %s = %s'
 801                             % (filename, section, ErrorString(error),
 802                                setting, value)), None, sys.exc_info()[2])
 803                     self.set(section, setting, new_value)
 804                 if option.overrides:
 805                     self.set(section, option.overrides, None)
 806
 807     def optionxform(self, optionstr):
 808         """
 809         Transform '-' to '_' so the cmdline form of option names can be used.
 810         """
 811         return optionstr.lower().replace('-', '_')
 812
 813     def get_section(self, section):
 814         """
 815         Return a given section as a dictionary (empty if the section
 816         doesn't exist).
 817         """
 818         section_dict = {}
 819         if self.has_section(section):
 820             for option in self.options(section):
 821                 section_dict[option] = self.get(section, option)
 822         return section_dict
 823
 824
 825 class ConfigDeprecationWarning(DeprecationWarning):
 826     """Warning for deprecated configuration file features."""