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# $Id: universal.py 9320 2023-01-17 15:40:15Z milde $
# Authors: David Goodger <goodger@python.org>; Ueli Schlaepfer; Günter Milde
# Maintainer: docutils-develop@lists.sourceforge.net
# Copyright: This module has been placed in the public domain.
"""
Transforms needed by most or all documents:
- `Decorations`: Generate a document's header & footer.
- `ExposeInternals`: Expose internal attributes.
- `Messages`: Placement of system messages generated after parsing.
- `FilterMessages`: Remove system messages below verbosity threshold.
- `TestMessages`: Like `Messages`, used on test runs.
- `StripComments`: Remove comment elements from the document tree.
- `StripClassesAndElements`: Remove elements with classes
in `self.document.settings.strip_elements_with_classes`
and class values in `self.document.settings.strip_classes`.
- `SmartQuotes`: Replace ASCII quotation marks with typographic form.
"""
__docformat__ = 'reStructuredText'
import re
import time
from docutils import nodes, utils
from docutils.transforms import Transform
from docutils.utils import smartquotes
class Decorations(Transform):
"""
Populate a document's decoration element (header, footer).
"""
default_priority = 820
def apply(self):
header_nodes = self.generate_header()
if header_nodes:
decoration = self.document.get_decoration()
header = decoration.get_header()
header.extend(header_nodes)
footer_nodes = self.generate_footer()
if footer_nodes:
decoration = self.document.get_decoration()
footer = decoration.get_footer()
footer.extend(footer_nodes)
def generate_header(self):
return None
def generate_footer(self):
# @@@ Text is hard-coded for now.
# Should be made dynamic (language-dependent).
# @@@ Use timestamp from the `SOURCE_DATE_EPOCH`_ environment variable
# for the datestamp?
# See https://sourceforge.net/p/docutils/patches/132/
# and https://reproducible-builds.org/specs/source-date-epoch/
settings = self.document.settings
if (settings.generator or settings.datestamp
or settings.source_link or settings.source_url):
text = []
if (settings.source_link and settings._source
or settings.source_url):
if settings.source_url:
source = settings.source_url
else:
source = utils.relative_path(settings._destination,
settings._source)
text.extend([
nodes.reference('', 'View document source',
refuri=source),
nodes.Text('.\n')])
if settings.datestamp:
datestamp = time.strftime(settings.datestamp, time.gmtime())
text.append(nodes.Text('Generated on: ' + datestamp + '.\n'))
if settings.generator:
text.extend([
nodes.Text('Generated by '),
nodes.reference('', 'Docutils',
refuri='https://docutils.sourceforge.io/'),
nodes.Text(' from '),
nodes.reference('', 'reStructuredText',
refuri='https://docutils.sourceforge.io/'
'rst.html'),
nodes.Text(' source.\n')])
return [nodes.paragraph('', '', *text)]
else:
return None
class ExposeInternals(Transform):
"""
Expose internal attributes if ``expose_internals`` setting is set.
"""
default_priority = 840
def not_Text(self, node):
return not isinstance(node, nodes.Text)
def apply(self):
if self.document.settings.expose_internals:
for node in self.document.findall(self.not_Text):
for att in self.document.settings.expose_internals:
value = getattr(node, att, None)
if value is not None:
node['internal:' + att] = value
class Messages(Transform):
"""
Place any system messages generated after parsing into a dedicated section
of the document.
"""
default_priority = 860
def apply(self):
messages = self.document.transform_messages
loose_messages = [msg for msg in messages if not msg.parent]
if loose_messages:
section = nodes.section(classes=['system-messages'])
# @@@ get this from the language module?
section += nodes.title('', 'Docutils System Messages')
section += loose_messages
self.document.transform_messages[:] = []
self.document += section
# TODO: fix bug #435:
# Messages are filtered at a very late stage
# This breaks the link from inline error messages to the corresponding
# system message at the end of document.
class FilterMessages(Transform):
"""
Remove system messages below verbosity threshold.
Convert <problematic> nodes referencing removed messages to <Text>.
Remove "System Messages" section if empty.
"""
default_priority = 870
def apply(self):
for node in tuple(self.document.findall(nodes.system_message)):
if node['level'] < self.document.reporter.report_level:
node.parent.remove(node)
try: # also remove id-entry
del self.document.ids[node['ids'][0]]
except (IndexError):
pass
for node in tuple(self.document.findall(nodes.problematic)):
if node['refid'] not in self.document.ids:
node.parent.replace(node, nodes.Text(node.astext()))
for node in self.document.findall(nodes.section):
if "system-messages" in node['classes'] and len(node) == 1:
node.parent.remove(node)
class TestMessages(Transform):
"""
Append all post-parse system messages to the end of the document.
Used for testing purposes.
"""
# marker for pytest to ignore this class during test discovery
__test__ = False
default_priority = 880
def apply(self):
for msg in self.document.transform_messages:
if not msg.parent:
self.document += msg
class StripComments(Transform):
"""
Remove comment elements from the document tree (only if the
``strip_comments`` setting is enabled).
"""
default_priority = 740
def apply(self):
if self.document.settings.strip_comments:
for node in tuple(self.document.findall(nodes.comment)):
node.parent.remove(node)
class StripClassesAndElements(Transform):
"""
Remove from the document tree all elements with classes in
`self.document.settings.strip_elements_with_classes` and all "classes"
attribute values in `self.document.settings.strip_classes`.
"""
default_priority = 420
def apply(self):
if self.document.settings.strip_elements_with_classes:
self.strip_elements = {*self.document.settings
.strip_elements_with_classes}
# Iterate over a tuple as removing the current node
# corrupts the iterator returned by `iter`:
for node in tuple(self.document.findall(self.check_classes)):
node.parent.remove(node)
if not self.document.settings.strip_classes:
return
strip_classes = self.document.settings.strip_classes
for node in self.document.findall(nodes.Element):
for class_value in strip_classes:
try:
node['classes'].remove(class_value)
except ValueError:
pass
def check_classes(self, node):
if not isinstance(node, nodes.Element):
return False
for class_value in node['classes'][:]:
if class_value in self.strip_elements:
return True
return False
class SmartQuotes(Transform):
"""
Replace ASCII quotation marks with typographic form.
Also replace multiple dashes with em-dash/en-dash characters.
"""
default_priority = 855
nodes_to_skip = (nodes.FixedTextElement, nodes.Special)
"""Do not apply "smartquotes" to instances of these block-level nodes."""
literal_nodes = (nodes.FixedTextElement, nodes.Special,
nodes.image, nodes.literal, nodes.math,
nodes.raw, nodes.problematic)
"""Do not apply smartquotes to instances of these inline nodes."""
smartquotes_action = 'qDe'
"""Setting to select smartquote transformations.
The default 'qDe' educates normal quote characters: (", '),
em- and en-dashes (---, --) and ellipses (...).
"""
def __init__(self, document, startnode):
Transform.__init__(self, document, startnode=startnode)
self.unsupported_languages = set()
def get_tokens(self, txtnodes):
# A generator that yields ``(texttype, nodetext)`` tuples for a list
# of "Text" nodes (interface to ``smartquotes.educate_tokens()``).
for node in txtnodes:
if (isinstance(node.parent, self.literal_nodes)
or isinstance(node.parent.parent, self.literal_nodes)):
yield 'literal', str(node)
else:
# SmartQuotes uses backslash escapes instead of null-escapes
# Insert backslashes before escaped "active" characters.
txt = re.sub('(?<=\x00)([-\\\'".`])', r'\\\1', str(node))
yield 'plain', txt
def apply(self):
smart_quotes = self.document.settings.setdefault('smart_quotes',
False)
if not smart_quotes:
return
try:
alternative = smart_quotes.startswith('alt')
except AttributeError:
alternative = False
document_language = self.document.settings.language_code
lc_smartquotes = self.document.settings.smartquotes_locales
if lc_smartquotes:
smartquotes.smartchars.quotes.update(dict(lc_smartquotes))
# "Educate" quotes in normal text. Handle each block of text
# (TextElement node) as a unit to keep context around inline nodes:
for node in self.document.findall(nodes.TextElement):
# skip preformatted text blocks and special elements:
if isinstance(node, self.nodes_to_skip):
continue
# nested TextElements are not "block-level" elements:
if isinstance(node.parent, nodes.TextElement):
continue
# list of text nodes in the "text block":
txtnodes = [txtnode for txtnode in node.findall(nodes.Text)
if not isinstance(txtnode.parent,
nodes.option_string)]
# language: use typographical quotes for language "lang"
lang = node.get_language_code(document_language)
# use alternative form if `smart-quotes` setting starts with "alt":
if alternative:
if '-x-altquot' in lang:
lang = lang.replace('-x-altquot', '')
else:
lang += '-x-altquot'
# drop unsupported subtags:
for tag in utils.normalize_language_tag(lang):
if tag in smartquotes.smartchars.quotes:
lang = tag
break
else: # language not supported -- keep ASCII quotes
if lang not in self.unsupported_languages:
self.document.reporter.warning(
'No smart quotes defined for language "%s".' % lang,
base_node=node)
self.unsupported_languages.add(lang)
lang = ''
# Iterator educating quotes in plain text:
# (see "utils/smartquotes.py" for the attribute setting)
teacher = smartquotes.educate_tokens(
self.get_tokens(txtnodes),
attr=self.smartquotes_action, language=lang)
for txtnode, newtext in zip(txtnodes, teacher):
txtnode.parent.replace(txtnode, nodes.Text(newtext))
self.unsupported_languages.clear()
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