third_party/markdown/extensions/meta.py

   1 # markdown is released under the BSD license
   2 # Copyright 2007, 2008 The Python Markdown Project (v. 1.7 and later)
   3 # Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
   4 # Copyright 2004 Manfred Stienstra (the original version)
   5 #
   6 # All rights reserved.
   7 #
   8 # Redistribution and use in source and binary forms, with or without
   9 # modification, are permitted provided that the following conditions are met:
  10 #
  11 # *   Redistributions of source code must retain the above copyright
  12 #     notice, this list of conditions and the following disclaimer.
  13 # *   Redistributions in binary form must reproduce the above copyright
  14 #     notice, this list of conditions and the following disclaimer in the
  15 #     documentation and/or other materials provided with the distribution.
  16 # *   Neither the name of the <organization> nor the
  17 #     names of its contributors may be used to endorse or promote products
  18 #     derived from this software without specific prior written permission.
  19 #
  20 # THIS SOFTWARE IS PROVIDED BY THE PYTHON MARKDOWN PROJECT ''AS IS'' AND ANY
  21 # EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  22 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  23 # DISCLAIMED. IN NO EVENT SHALL ANY CONTRIBUTORS TO THE PYTHON MARKDOWN PROJECT
  24 # BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  25 # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  26 # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27 # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28 # CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  29 # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30 # POSSIBILITY OF SUCH DAMAGE.
  31
  32
  33 """
  34 Meta Data Extension for Python-Markdown
  35 =======================================
  36
  37 This extension adds Meta Data handling to markdown.
  38
  39 Basic Usage:
  40
  41     >>> import markdown
  42     >>> text = '''Title: A Test Doc.
  43     ... Author: Waylan Limberg
  44     ...         John Doe
  45     ... Blank_Data:
  46     ...
  47     ... The body. This is paragraph one.
  48     ... '''
  49     >>> md = markdown.Markdown(['meta'])
  50     >>> print md.convert(text)
  51     <p>The body. This is paragraph one.</p>
  52     >>> print md.Meta
  53     {u'blank_data': [u''], u'author': [u'Waylan Limberg', u'John Doe'], u'title': [u'A Test Doc.']}
  54
  55 Make sure text without Meta Data still works (markdown < 1.6b returns a <p>).
  56
  57     >>> text = '    Some Code - not extra lines of meta data.'
  58     >>> md = markdown.Markdown(['meta'])
  59     >>> print md.convert(text)
  60     <pre><code>Some Code - not extra lines of meta data.
  61     </code></pre>
  62     >>> md.Meta
  63     {}
  64
  65 Copyright 2007-2008 [Waylan Limberg](http://achinghead.com).
  66
  67 Project website: <http://packages.python.org/Markdown/meta_data.html>
  68 Contact: markdown@freewisdom.org
  69
  70 License: BSD (see ../LICENSE.md for details)
  71
  72 """
  73
  74 from __future__ import absolute_import
  75 from __future__ import unicode_literals
  76 from . import Extension
  77 from ..preprocessors import Preprocessor
  78 import re
  79
  80 # Global Vars
  81 META_RE = re.compile(r'^[ ]{0,3}(?P<key>[A-Za-z0-9_-]+):\s*(?P<value>.*)')
  82 META_MORE_RE = re.compile(r'^[ ]{4,}(?P<value>.*)')
  83
  84 class MetaExtension (Extension):
  85     """ Meta-Data extension for Python-Markdown. """
  86
  87     def extendMarkdown(self, md, md_globals):
  88         """ Add MetaPreprocessor to Markdown instance. """
  89
  90         md.preprocessors.add("meta", MetaPreprocessor(md), "_begin")
  91
  92
  93 class MetaPreprocessor(Preprocessor):
  94     """ Get Meta-Data. """
  95
  96     def run(self, lines):
  97         """ Parse Meta-Data and store in Markdown.Meta. """
  98         meta = {}
  99         key = None
 100         while 1:
 101             line = lines.pop(0)
 102             if line.strip() == '':
 103                 break # blank line - done
 104             m1 = META_RE.match(line)
 105             if m1:
 106                 key = m1.group('key').lower().strip()
 107                 value = m1.group('value').strip()
 108                 try:
 109                     meta[key].append(value)
 110                 except KeyError:
 111                     meta[key] = [value]
 112             else:
 113                 m2 = META_MORE_RE.match(line)
 114                 if m2 and key:
 115                     # Add another line to existing key
 116                     meta[key].append(m2.group('value').strip())
 117                 else:
 118                     lines.insert(0, line)
 119                     break # no meta data - done
 120         self.markdown.Meta = meta
 121         return lines
 122
 123
 124 def makeExtension(configs={}):
 125     return MetaExtension(configs=configs)