1 files changed, 86 insertions, 0 deletions
diff --git a/markdown/extensions/__init__.py b/markdown/extensions/__init__.py
index e69de29..2d8d72a 100644
--- a/markdown/extensions/__init__.py
+++ b/markdown/extensions/__init__.py
@@ -0,0 +1,86 @@
+"""
+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).
+"""
+
+from ..util import parseBoolValue
+
+
+class Extension:
+    """ Base class for extensions to subclass. """
+
+    # Default config -- to be overridden by a subclass
+    # Must be of the following format:
+    #     {
+    #       'key': ['value', 'description']
+    #     }
+    # Note that Extension.setConfig will raise a KeyError
+    # if a default is not set here.
+    config = {}
+
+    def __init__(self, **kwargs):
+        """ Initiate Extension and set up configs. """
+        self.setConfigs(kwargs)
+
+    def getConfig(self, key, default=''):
+        """ Return a setting for the given key or an empty string. """
+        if key in self.config:
+            return self.config[key][0]
+        else:
+            return default
+
+    def getConfigs(self):
+        """ Return all configs settings as a dict. """
+        return {key: self.getConfig(key) for key in self.config.keys()}
+
+    def getConfigInfo(self):
+        """ Return all config descriptions as a list of tuples. """
+        return [(key, self.config[key][1]) for key in self.config.keys()]
+
+    def setConfig(self, key, value):
+        """ Set a config setting for `key` with the given `value`. """
+        if isinstance(self.config[key][0], bool):
+            value = parseBoolValue(value)
+        if self.config[key][0] is None:
+            value = parseBoolValue(value, preserve_none=True)
+        self.config[key][0] = value
+
+    def setConfigs(self, items):
+        """ Set multiple config settings given a dict or list of tuples. """
+        if hasattr(items, 'items'):
+            # it's a dict
+            items = items.items()
+        for key, value in items:
+            self.setConfig(key, value)
+
+    def extendMarkdown(self, md):
+        """
+        Add the various processors and patterns to the Markdown Instance.
+
+        This method must be overridden by every extension.
+
+        Keyword arguments:
+
+        * md: The Markdown instance.
+
+        """
+        raise NotImplementedError(
+            'Extension "%s.%s" must define an "extendMarkdown"'
+            'method.' % (self.__class__.__module__, self.__class__.__name__)
+        )