1 files changed, 173 insertions, 0 deletions
diff --git a/mdx_headerid.py b/mdx_headerid.py
new file mode 100644
index 0000000..2e658cd
--- /dev/null
+++ b/mdx_headerid.py
@@ -0,0 +1,173 @@
+#!/usr/bin/python
+
+"""
+HeaderID Extension for Python-Markdown
+======================================
+
+Adds ability to set HTML IDs for headers.
+
+Basic usage:
+
+    >>> import markdown
+    >>> text = "# Some Header # {#some_id}"
+    >>> md = markdown.markdown(text, ['headerid'])
+    >>> md
+    u'<h1 id="some_id">Some Header</h1>'
+
+All header IDs are unique:
+
+    >>> text = '''
+    ... #Header
+    ... #Another Header {#header}
+    ... #Third Header {#header}'''
+    >>> md = markdown.markdown(text, ['headerid'])
+    >>> md
+    u'<h1 id="header">Header</h1>\\n\\n<h1 id="header_1">Another Header</h1>\\n\\n<h1 id="header_2">Third Header</h1>'
+
+To fit within a html template's hierarchy, set the header base level:
+
+    >>> text = '''
+    ... #Some Header
+    ... ## Next Level'''
+    >>> md = markdown.markdown(text, ['headerid(level=3)'])
+    >>> md
+    u'<h3 id="some_header">Some Header</h3>\\n\\n<h4 id="next_level">Next Level</h4>'
+
+Turn off auto generated IDs:
+
+    >>> text = '''
+    ... # Some Header
+    ... # Header with ID # { #foo }'''
+    >>> md = markdown.markdown(text, ['headerid(forceid=False)'])
+    >>> md
+    u'<h1>Some Header</h1>\\n\\n<h1 id="foo">Header with ID</h1>'
+
+Use with MetaData extension:
+
+    >>> text = '''header_level: 2
+    ... header_forceid: Off
+    ...
+    ... # A Header'''
+    >>> md = markdown.markdown(text, ['headerid', 'meta'])
+    >>> md
+    u'<h2>A Header</h2>'
+
+By [Waylan Limberg](http://achinghead.com/).
+
+Project website: http://achinghead.com/markdown-headerid/
+Contact: waylan [at] gmail [dot] com
+
+License: [BSD](http://www.opensource.org/licenses/bsd-license.php) 
+
+Version: 0.1 (May 2, 2008)
+
+Dependencies:
+* [Python 2.3+](http://python.org)
+* [Markdown 1.7+](http://www.freewisdom.org/projects/python-markdown/)
+
+"""
+
+import markdown
+import re
+from string import ascii_lowercase, digits, punctuation
+
+ID_CHARS = ascii_lowercase + digits + '-_'
+
+HEADER_RE = re.compile(r'''^(\#{1,6})		# group(1) = string of hashes
+                           ( [^{^#]*)		# group(2) = Header text
+                           [\#]*		    # optional closing hashes (not counted)
+                           (?:[ \t]*\{[ \t]*\#([-_:a-zA-Z0-9]+)[ \t]*\})?	# group(3) = id attr''',
+                           re.VERBOSE)
+
+IDCOUNT_RE = re.compile(r'^(.*)_([0-9]+)$')
+
+class HeaderIdExtension (markdown.Extension) :
+    def __init__(self, configs):
+        # set defaults
+        self.config = {
+                'level' : ['1', 'Base level for headers.'],
+                'forceid' : ['True', 'Force all headers to have an id.']
+            }
+
+        for key, value in configs:
+            self.setConfig(key, value)
+
+
+    def extendMarkdown(self, md, md_globals) :
+
+        md.IDs = []
+
+        def _processHeaderId(parent_elem, paragraph) :
+            ''' 
+            Overrides _processHeader of Markdown() and 
+            adds an 'id' to the header. 
+            '''
+            m = HEADER_RE.match(paragraph[0])
+            if m :
+                start_level, force_id = _get_meta()
+                level = len(m.group(1)) + start_level
+                if level > 6: level = 6
+                h = md.doc.createElement("h%d" % level)
+                parent_elem.appendChild(h)
+                for item in md._handleInline(m.group(2).strip()) :
+                    h.appendChild(item)
+                if m.group(3) :
+                    h.setAttribute('id', _unique_id(m.group(3)))
+                elif force_id:
+                    h.setAttribute('id', _create_id(m.group(2).strip()))
+            else :
+                message(CRITICAL, "We've got a problem header!")
+        
+        md._processHeader = _processHeaderId
+
+        def _get_meta():
+            ''' Return meta data suported by this ext as a tuple '''
+            level = int(self.config['level'][0]) - 1
+            force = _str2bool(self.config['forceid'][0])
+            if hasattr(md, 'Meta'):
+                if md.Meta.has_key('header_level'):
+                    level = int(md.Meta['header_level'][0]) - 1
+                if md.Meta.has_key('header_forceid'): 
+                    force = _str2bool(md.Meta['header_forceid'][0])
+            return level, force
+
+        def _str2bool(s, default=False):
+            ''' Convert a string to a booleen value. '''
+            s = str(s)
+            if s.lower() in ['0', 'f', 'false', 'off', 'no', 'n']:
+                return False
+            elif s.lower() in ['1', 't', 'true', 'on', 'yes', 'y']:
+                    return True
+            return default
+
+        def _unique_id(id):
+            ''' Ensure ID is unique. Append '_1', '_2'... if not '''
+            while id in md.IDs:
+                m = IDCOUNT_RE.match(id)
+                if m:
+                    id = '%s_%d'% (m.group(1), int(m.group(2))+1)
+                else:
+                    id = '%s_%d'% (id, 1)
+            md.IDs.append(id)
+            return id
+
+
+        def _create_id(header):
+            ''' Return ID from Header text. '''
+            h = ''
+            for c in header.lower().replace(' ', '_'):
+                if c in ID_CHARS:
+                    h += c
+                elif c not in punctuation:
+                    h += '+'
+            return _unique_id(h)
+
+            
+
+def makeExtension(configs=None) :
+    return HeaderIdExtension(configs=configs)
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()
+