120 lines
4.1 KiB
Python
120 lines
4.1 KiB
Python
"""
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Python Markdown
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A Python implementation of John Gruber's Markdown.
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Documentation: https://python-markdown.github.io/
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GitHub: https://github.com/Python-Markdown/markdown/
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PyPI: https://pypi.org/project/Markdown/
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Started by Manfred Stienstra (http://www.dwerg.net/).
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Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
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Currently maintained by Waylan Limberg (https://github.com/waylan),
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Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
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Copyright 2007-2018 The Python Markdown Project (v. 1.7 and later)
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Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
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Copyright 2004 Manfred Stienstra (the original version)
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License: BSD (see LICENSE.md for details).
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"""
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import xml.etree.ElementTree as etree
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from . import util
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class State(list):
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""" Track the current and nested state of the parser.
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This utility class is used to track the state of the `BlockParser` and
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support multiple levels if nesting. It's just a simple API wrapped around
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a list. Each time a state is set, that state is appended to the end of the
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list. Each time a state is reset, that state is removed from the end of
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the list.
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Therefore, each time a state is set for a nested block, that state must be
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reset when we back out of that level of nesting or the state could be
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corrupted.
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While all the methods of a list object are available, only the three
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defined below need be used.
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"""
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def set(self, state):
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""" Set a new state. """
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self.append(state)
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def reset(self):
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""" Step back one step in nested state. """
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self.pop()
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def isstate(self, state):
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""" Test that top (current) level is of given state. """
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if len(self):
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return self[-1] == state
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else:
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return False
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class BlockParser:
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""" Parse Markdown blocks into an `ElementTree` object.
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A wrapper class that stitches the various `BlockProcessors` together,
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looping through them and creating an `ElementTree` object.
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"""
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def __init__(self, md):
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self.blockprocessors = util.Registry()
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self.state = State()
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self.md = md
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def parseDocument(self, lines):
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""" Parse a markdown document into an ElementTree.
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Given a list of lines, an ElementTree object (not just a parent
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Element) is created and the root element is passed to the parser
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as the parent. The ElementTree object is returned.
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This should only be called on an entire document, not pieces.
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"""
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# Create an `ElementTree` from the lines
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self.root = etree.Element(self.md.doc_tag)
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self.parseChunk(self.root, '\n'.join(lines))
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return etree.ElementTree(self.root)
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def parseChunk(self, parent, text):
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""" Parse a chunk of markdown text and attach to given `etree` node.
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While the `text` argument is generally assumed to contain multiple
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blocks which will be split on blank lines, it could contain only one
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block. Generally, this method would be called by extensions when
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block parsing is required.
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The `parent` `etree` Element passed in is altered in place.
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Nothing is returned.
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"""
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self.parseBlocks(parent, text.split('\n\n'))
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def parseBlocks(self, parent, blocks):
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""" Process blocks of markdown text and attach to given `etree` node.
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Given a list of `blocks`, each `blockprocessor` is stepped through
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until there are no blocks left. While an extension could potentially
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call this method directly, it's generally expected to be used
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internally.
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This is a public method as an extension may need to add/alter
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additional `BlockProcessors` which call this method to recursively
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parse a nested block.
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"""
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while blocks:
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for processor in self.blockprocessors:
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if processor.test(parent, blocks[0]):
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if processor.run(parent, blocks) is not False:
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# run returns True or None
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break
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