""" Python Markdown A Python implementation of John Gruber's Markdown. Documentation: https://python-markdown.github.io/ GitHub: https://github.com/Python-Markdown/markdown/ PyPI: https://pypi.org/project/Markdown/ Started by Manfred Stienstra (http://www.dwerg.net/). Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org). Currently maintained by Waylan Limberg (https://github.com/waylan), Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser). Copyright 2007-2018 The Python Markdown Project (v. 1.7 and later) Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b) Copyright 2004 Manfred Stienstra (the original version) License: BSD (see LICENSE.md for details). """ import codecs import sys import logging import importlib from . import util from .preprocessors import build_preprocessors from .blockprocessors import build_block_parser from .treeprocessors import build_treeprocessors from .inlinepatterns import build_inlinepatterns from .postprocessors import build_postprocessors from .extensions import Extension from .serializers import to_html_string, to_xhtml_string __all__ = ['Markdown', 'markdown', 'markdownFromFile'] logger = logging.getLogger('MARKDOWN') class Markdown: """Convert Markdown to HTML.""" doc_tag = "div" # Element used to wrap document - later removed output_formats = { 'html': to_html_string, 'xhtml': to_xhtml_string, } def __init__(self, **kwargs): """ Creates a new Markdown instance. Keyword arguments: * extensions: A list of extensions. If an item is an instance of a subclass of `markdown.extension.Extension`, the instance will be used as-is. If an item is of type string, first an entry point will be loaded. If that fails, the string is assumed to use Python dot notation (`path.to.module:ClassName`) to load a markdown.Extension subclass. If no class is specified, then a `makeExtension` function is called within the specified module. * extension_configs: Configuration settings for extensions. * output_format: Format of output. Supported formats are: * "xhtml": Outputs XHTML style tags. Default. * "html": Outputs HTML style tags. * tab_length: Length of tabs in the source. Default: 4 """ self.tab_length = kwargs.get('tab_length', 4) self.ESCAPED_CHARS = ['\\', '`', '*', '_', '{', '}', '[', ']', '(', ')', '>', '#', '+', '-', '.', '!'] self.block_level_elements = [ # Elements which are invalid to wrap in a `

` tag. # See https://w3c.github.io/html/grouping-content.html#the-p-element 'address', 'article', 'aside', 'blockquote', 'details', 'div', 'dl', 'fieldset', 'figcaption', 'figure', 'footer', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'header', 'hr', 'main', 'menu', 'nav', 'ol', 'p', 'pre', 'section', 'table', 'ul', # Other elements which Markdown should not be mucking up the contents of. 'canvas', 'dd', 'dt', 'group', 'iframe', 'li', 'math', 'noscript', 'output', 'progress', 'script', 'style', 'tbody', 'td', 'th', 'thead', 'tr', 'video' ] self.registeredExtensions = [] self.docType = "" self.stripTopLevelTags = True self.build_parser() self.references = {} self.htmlStash = util.HtmlStash() self.registerExtensions(extensions=kwargs.get('extensions', []), configs=kwargs.get('extension_configs', {})) self.set_output_format(kwargs.get('output_format', 'xhtml')) self.reset() def build_parser(self): """ Build the parser from the various parts. """ self.preprocessors = build_preprocessors(self) self.parser = build_block_parser(self) self.inlinePatterns = build_inlinepatterns(self) self.treeprocessors = build_treeprocessors(self) self.postprocessors = build_postprocessors(self) return self def registerExtensions(self, extensions, configs): """ Register extensions with this instance of Markdown. Keyword arguments: * extensions: A list of extensions, which can either be strings or objects. * configs: A dictionary mapping extension names to config options. """ for ext in extensions: if isinstance(ext, str): ext = self.build_extension(ext, configs.get(ext, {})) if isinstance(ext, Extension): ext._extendMarkdown(self) logger.debug( 'Successfully loaded extension "%s.%s".' % (ext.__class__.__module__, ext.__class__.__name__) ) elif ext is not None: raise TypeError( 'Extension "{}.{}" must be of type: "{}.{}"'.format( ext.__class__.__module__, ext.__class__.__name__, Extension.__module__, Extension.__name__ ) ) return self def build_extension(self, ext_name, configs): """ Build extension from a string name, then return an instance. First attempt to load an entry point. The string name must be registered as an entry point in the `markdown.extensions` group which points to a subclass of the `markdown.extensions.Extension` class. If multiple distributions have registered the same name, the first one found is returned. If no entry point is found, assume dot notation (`path.to.module:ClassName`). Load the specified class and return an instance. If no class is specified, import the module and call a `makeExtension` function and return the Extension instance returned by that function. """ configs = dict(configs) entry_points = [ep for ep in util.INSTALLED_EXTENSIONS if ep.name == ext_name] if entry_points: ext = entry_points[0].load() return ext(**configs) # Get class name (if provided): `path.to.module:ClassName` ext_name, class_name = ext_name.split(':', 1) if ':' in ext_name else (ext_name, '') try: module = importlib.import_module(ext_name) logger.debug( 'Successfully imported extension module "%s".' % ext_name ) except ImportError as e: message = 'Failed loading extension "%s".' % ext_name e.args = (message,) + e.args[1:] raise if class_name: # Load given class name from module. return getattr(module, class_name)(**configs) else: # Expect makeExtension() function to return a class. try: return module.makeExtension(**configs) except AttributeError as e: message = e.args[0] message = "Failed to initiate extension " \ "'%s': %s" % (ext_name, message) e.args = (message,) + e.args[1:] raise def registerExtension(self, extension): """ This gets called by the extension """ self.registeredExtensions.append(extension) return self def reset(self): """ Resets all state variables so that we can start with a new text. """ self.htmlStash.reset() self.references.clear() for extension in self.registeredExtensions: if hasattr(extension, 'reset'): extension.reset() return self def set_output_format(self, format): """ Set the output format for the class instance. """ self.output_format = format.lower().rstrip('145') # ignore num try: self.serializer = self.output_formats[self.output_format] except KeyError as e: valid_formats = list(self.output_formats.keys()) valid_formats.sort() message = 'Invalid Output Format: "%s". Use one of %s.' \ % (self.output_format, '"' + '", "'.join(valid_formats) + '"') e.args = (message,) + e.args[1:] raise return self def is_block_level(self, tag): """Check if the tag is a block level HTML tag.""" if isinstance(tag, str): return tag.lower().rstrip('/') in self.block_level_elements # Some ElementTree tags are not strings, so return False. return False def convert(self, source): """ Convert markdown to serialized XHTML or HTML. Keyword arguments: * source: Source text as a Unicode string. Markdown processing takes place in five steps: 1. A bunch of "preprocessors" munge the input text. 2. BlockParser() parses the high-level structural elements of the pre-processed text into an ElementTree. 3. A bunch of "treeprocessors" are run against the ElementTree. One such treeprocessor runs InlinePatterns against the ElementTree, detecting inline markup. 4. Some post-processors are run against the text after the ElementTree has been serialized into text. 5. The output is written to a string. """ # Fixup the source text if not source.strip(): return '' # a blank unicode string try: source = str(source) except UnicodeDecodeError as e: # pragma: no cover # Customise error message while maintaining original trackback e.reason += '. -- Note: Markdown only accepts unicode input!' raise # Split into lines and run the line preprocessors. self.lines = source.split("\n") for prep in self.preprocessors: self.lines = prep.run(self.lines) # Parse the high-level elements. root = self.parser.parseDocument(self.lines).getroot() # Run the tree-processors for treeprocessor in self.treeprocessors: newRoot = treeprocessor.run(root) if newRoot is not None: root = newRoot # Serialize _properly_. Strip top-level tags. output = self.serializer(root) if self.stripTopLevelTags: try: start = output.index( '<%s>' % self.doc_tag) + len(self.doc_tag) + 2 end = output.rindex('' % self.doc_tag) output = output[start:end].strip() except ValueError: # pragma: no cover if output.strip().endswith('<%s />' % self.doc_tag): # We have an empty document output = '' else: # We have a serious problem raise ValueError('Markdown failed to strip top-level ' 'tags. Document=%r' % output.strip()) # Run the text post-processors for pp in self.postprocessors: output = pp.run(output) return output.strip() def convertFile(self, input=None, output=None, encoding=None): """Converts a markdown file and returns the HTML as a unicode string. Decodes the file using the provided encoding (defaults to utf-8), passes the file content to markdown, and outputs the html to either the provided stream or the file with provided name, using the same encoding as the source file. The 'xmlcharrefreplace' error handler is used when encoding the output. **Note:** This is the only place that decoding and encoding of unicode takes place in Python-Markdown. (All other code is unicode-in / unicode-out.) Keyword arguments: * input: File object or path. Reads from stdin if `None`. * output: File object or path. Writes to stdout if `None`. * encoding: Encoding of input and output files. Defaults to utf-8. """ encoding = encoding or "utf-8" # Read the source if input: if isinstance(input, str): input_file = codecs.open(input, mode="r", encoding=encoding) else: input_file = codecs.getreader(encoding)(input) text = input_file.read() input_file.close() else: text = sys.stdin.read() if not isinstance(text, str): # pragma: no cover text = text.decode(encoding) text = text.lstrip('\ufeff') # remove the byte-order mark # Convert html = self.convert(text) # Write to file or stdout if output: if isinstance(output, str): output_file = codecs.open(output, "w", encoding=encoding, errors="xmlcharrefreplace") output_file.write(html) output_file.close() else: writer = codecs.getwriter(encoding) output_file = writer(output, errors="xmlcharrefreplace") output_file.write(html) # Don't close here. User may want to write more. else: # Encode manually and write bytes to stdout. html = html.encode(encoding, "xmlcharrefreplace") try: # Write bytes directly to buffer (Python 3). sys.stdout.buffer.write(html) except AttributeError: # pragma: no cover # Probably Python 2, which works with bytes by default. sys.stdout.write(html) return self """ EXPORTED FUNCTIONS ============================================================================= Those are the two functions we really mean to export: markdown() and markdownFromFile(). """ def markdown(text, **kwargs): """Convert a markdown string to HTML and return HTML as a unicode string. This is a shortcut function for `Markdown` class to cover the most basic use case. It initializes an instance of Markdown, loads the necessary extensions and runs the parser on the given text. Keyword arguments: * text: Markdown formatted text as Unicode or ASCII string. * Any arguments accepted by the Markdown class. Returns: An HTML document as a string. """ md = Markdown(**kwargs) return md.convert(text) def markdownFromFile(**kwargs): """Read markdown code from a file and write it to a file or a stream. This is a shortcut function which initializes an instance of Markdown, and calls the convertFile method rather than convert. Keyword arguments: * input: a file name or readable object. * output: a file name or writable object. * encoding: Encoding of input and output. * Any arguments accepted by the Markdown class. """ md = Markdown(**kwargs) md.convertFile(kwargs.get('input', None), kwargs.get('output', None), kwargs.get('encoding', None))