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