| # Copyright 2015 The Chromium Authors |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Implements Gitiles' notification, aside and promotion blocks. |
| |
| This extention makes the Markdown parser recognize the Gitiles' extended |
| blocks notation. The syntax is explained at: |
| |
| https://gerrit.googlesource.com/gitiles/+/master/Documentation/markdown.md#Notification_aside_promotion-blocks |
| """ |
| |
| from markdown.blockprocessors import BlockProcessor |
| from markdown.extensions import Extension |
| import re |
| import xml.etree.ElementTree as etree |
| |
| |
| class _GitilesExtBlockProcessor(BlockProcessor): |
| """Process Gitiles' notification, aside and promotion blocks.""" |
| |
| RE_START = re.compile(r'^\*\*\* (note|aside|promo) *\n') |
| RE_END = re.compile(r'\n\*\*\* *\n?$') |
| |
| def __init__(self, *args, **kwargs): |
| self._last_parent = None |
| BlockProcessor.__init__(self, *args, **kwargs) |
| |
| def test(self, parent, block): |
| return self.RE_START.search(block) or self.RE_END.search(block) |
| |
| def run(self, parent, blocks): |
| raw_block = blocks.pop(0) |
| match_start = self.RE_START.search(raw_block) |
| if match_start: |
| # Opening a new block. |
| rest = raw_block[match_start.end():] |
| |
| if self._last_parent: |
| # Inconsistent state (nested starting markers). Ignore the marker |
| # and keep going. |
| blocks.insert(0, rest) |
| return |
| |
| div = etree.SubElement(parent, 'div') |
| # Setting the class name is sufficient, because doc.css already has |
| # styles for these classes. |
| div.set('class', match_start.group(1)) |
| self._last_parent = parent |
| blocks.insert(0, rest) |
| self.parser.parseBlocks(div, blocks) |
| return |
| |
| match_end = self.RE_END.search(raw_block) |
| if match_end: |
| # Ending an existing block. |
| |
| # Process the text preceding the ending marker in the current context |
| # (i.e. within the div block). |
| rest = raw_block[:match_end.start()] |
| self.parser.parseBlocks(parent, [rest]) |
| |
| if not self._last_parent: |
| # Inconsistent state (the ending marker is found but there is no |
| # matching starting marker). |
| # Let's continue as if we did not see the ending marker. |
| return |
| |
| last_parent = self._last_parent |
| self._last_parent = None |
| self.parser.parseBlocks(last_parent, blocks) |
| return |
| |
| |
| class _GitilesExtBlockExtension(Extension): |
| """Add Gitiles' extended blocks to Markdown, with a priority higher than the |
| highest builtin.""" |
| |
| def extendMarkdown(self, md): |
| md.parser.blockprocessors.register(_GitilesExtBlockProcessor(md.parser), |
| 'gitilesextblocks', 101) |
| |
| |
| def makeExtension(*args, **kwargs): |
| return _GitilesExtBlockExtension(*args, **kwargs) |
