pokedex/db/markdown.py

   1 # encoding: utf8
   2 u"""Implements the markup used for description and effect text in the database.
   3
   4 The language used is a variation of Markdown and Markdown Extra.  There are
   5 docs for each at http://daringfireball.net/projects/markdown/ and
   6 http://michelf.com/projects/php-markdown/extra/ respectively.
   7
   8 Pokédex links are represented with the extended syntax `[name]{type}`, e.g.,
   9 `[Eevee]{pokemon}`.  The actual code that parses these is in spline-pokedex.
  10 """
  11 from __future__ import absolute_import
  12
  13 import markdown
  14 import sqlalchemy.types
  15
  16 class MarkdownString(object):
  17     """Wraps a Markdown string.  Stringifies to the original text, but .as_html
  18     will return an HTML rendering.
  19
  20     To add extensions to the rendering (which is necessary for rendering links
  21     correctly, and which spline-pokedex does), you must append to this class's
  22     `markdown_extensions` list.  Yep, that's gross.
  23     """
  24
  25     markdown_extensions = ['extra']
  26
  27     def __init__(self, source_text):
  28         self.source_text = source_text
  29         self._as_html = None
  30
  31     def __unicode__(self):
  32         return self.source_text
  33
  34     @property
  35     def as_html(self):
  36         """Returns the string as HTML4."""
  37
  38         if self._as_html:
  39             return self._as_html
  40
  41         md = markdown.Markdown(
  42             extensions=self.markdown_extensions,
  43             safe_mode='escape',
  44             output_format='xhtml1',
  45         )
  46
  47         self._as_html = md.convert(self.source_text)
  48
  49         return self._as_html
  50
  51     @property
  52     def as_text(self):
  53         """Returns the string in a plaintext-friendly form.
  54
  55         At the moment, this is just the original source text.
  56         """
  57         return self.source_text
  58
  59
  60 class MoveEffectProperty(object):
  61     """Property that wraps a move effect.  Used like this:
  62
  63         MoveClass.effect = MoveEffectProperty('effect')
  64
  65         some_move.effect            # returns a MarkdownString
  66         some_move.effect.as_html    # returns a chunk of HTML
  67
  68     This class also performs simple substitution on the effect, replacing
  69     `$effect_chance` with the move's actual effect chance.
  70     """
  71
  72     def __init__(self, effect_column):
  73         self.effect_column = effect_column
  74
  75     def __get__(self, move, move_class):
  76         effect_text = getattr(move.move_effect, self.effect_column)
  77         effect_text = effect_text.replace(
  78             u'$effect_chance',
  79             unicode(move.effect_chance),
  80         )
  81
  82         return MarkdownString(effect_text)
  83
  84 class MarkdownColumn(sqlalchemy.types.TypeDecorator):
  85     """Generic SQLAlchemy column type for Markdown text.
  86
  87     Do NOT use this for move effects!  They need to know what move they belong
  88     to so they can fill in, e.g., effect chances.  Use the MoveEffectProperty
  89     property class above.
  90     """
  91     impl = sqlalchemy.types.Unicode
  92
  93     def process_bind_param(self, value, dialect):
  94         if not isinstance(value, basestring):
  95             # Can't assign, e.g., MarkdownString objects yet
  96             raise NotImplementedError
  97
  98         return unicode(value)
  99
 100     def process_result_value(self, value, dialect):
 101         return MarkdownString(value)