Check in a simple pure-python based Markdown previewer.

third_party/Python-Markdown/markdown/extensions/admonition.py

+"""
+Admonition extension for Python-Markdown
+========================================
+
+Adds rST-style admonitions. Inspired by [rST][] feature with the same name.
+
+[rST]: http://docutils.sourceforge.net/docs/ref/rst/directives.html#specific-admonitions  # noqa
+
+See <https://pythonhosted.org/Markdown/extensions/admonition.html>
+for documentation.
+
+Original code Copyright [Tiago Serafim](http://www.tiagoserafim.com/).
+
+All changes Copyright The Python Markdown Project
+
+License: [BSD](http://www.opensource.org/licenses/bsd-license.php)
+
+"""
+
+from __future__ import absolute_import
+from __future__ import unicode_literals
+from . import Extension
+from ..blockprocessors import BlockProcessor
+from ..util import etree
+import re
+
+
+class AdmonitionExtension(Extension):
+    """ Admonition extension for Python-Markdown. """
+
+    def extendMarkdown(self, md, md_globals):
+        """ Add Admonition to Markdown instance. """
+        md.registerExtension(self)
+
+        md.parser.blockprocessors.add('admonition',
+                                      AdmonitionProcessor(md.parser),
+                                      '_begin')
+
+
+class AdmonitionProcessor(BlockProcessor):
+
+    CLASSNAME = 'admonition'
+    CLASSNAME_TITLE = 'admonition-title'
+    RE = re.compile(r'(?:^|\n)!!!\ ?([\w\-]+)(?:\ "(.*?)")?')
+
+    def test(self, parent, block):
+        sibling = self.lastChild(parent)
+        return self.RE.search(block) or \
+            (block.startswith(' ' * self.tab_length) and sibling is not None and
+             sibling.get('class', '').find(self.CLASSNAME) != -1)
+
+    def run(self, parent, blocks):
+        sibling = self.lastChild(parent)
+        block = blocks.pop(0)
+        m = self.RE.search(block)
+
+        if m:
+            block = block[m.end() + 1:]  # removes the first line
+
+        block, theRest = self.detab(block)
+
+        if m:
+            klass, title = self.get_class_and_title(m)
+            div = etree.SubElement(parent, 'div')
+            div.set('class', '%s %s' % (self.CLASSNAME, klass))
+            if title:
+                p = etree.SubElement(div, 'p')
+                p.text = title
+                p.set('class', self.CLASSNAME_TITLE)
+        else:
+            div = sibling
+
+        self.parser.parseChunk(div, block)
+
+        if theRest:
+            # This block contained unindented line(s) after the first indented
+            # line. Insert these lines as the first block of the master blocks
+            # list for future processing.
+            blocks.insert(0, theRest)
+
+    def get_class_and_title(self, match):
+        klass, title = match.group(1).lower(), match.group(2)
+        if title is None:
+            # no title was provided, use the capitalized classname as title
+            # e.g.: `!!! note` will render
+            # `<p class="admonition-title">Note</p>`
+            title = klass.capitalize()
+        elif title == '':
+            # an explicit blank title should not be rendered
+            # e.g.: `!!! warning ""` will *not* render `p` with a title
+            title = None
+        return klass, title
+
+
+def makeExtension(*args, **kwargs):
+    return AdmonitionExtension(*args, **kwargs)