| """ |
| 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 `<p>` 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', 'hgroup', 'hr', 'main', 'menu', 'nav', 'ol', |
| 'p', 'pre', 'section', 'table', 'ul', |
| # Other elements which Markdown should not be mucking up the contents of. |
| 'canvas', 'colgroup', 'dd', 'body', 'dt', 'group', 'iframe', 'li', 'legend', |
| 'math', 'map', 'noscript', 'output', 'object', 'option', 'progress', 'script', |
| 'style', 'summary', 'tbody', 'td', 'textarea', 'tfoot', '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.get_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('</%s>' % self.doc_tag) |
| output = output[start:end].strip() |
| except ValueError as e: # 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()) from e |
| |
| # 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)) |
