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     def __str__(self):
  35         return unicode(self.source_text).encode()
  36
  37     def __html__(self):
  38         return self.as_html
  39
  40     @property
  41     def as_html(self):
  42         """Returns the string as HTML4."""
  43
  44         if self._as_html is not None:
  45             return self._as_html
  46
  47         md = markdown.Markdown(
  48             extensions=self.markdown_extensions,
  49             safe_mode='escape',
  50             output_format='xhtml1',
  51         )
  52
  53         self._as_html = md.convert(self.source_text)
  54
  55         return self._as_html
  56
  57     @property
  58     def as_text(self):
  59         """Returns the string in a plaintext-friendly form.
  60
  61         At the moment, this is just the original source text.
  62         """
  63         return self.source_text
  64
  65 def _markdownify_effect_text(move, effect_text):
  66     effect_text = effect_text.replace(
  67         u'$effect_chance',
  68         unicode(move.effect_chance),
  69     )
  70
  71     return MarkdownString(effect_text)
  72
  73 class MoveEffectProperty(object):
  74     """Property that wraps move effects.  Used like this:
  75
  76         MoveClass.effect = MoveEffectProperty('effect')
  77
  78         some_move.effect            # returns a MarkdownString
  79         some_move.effect.as_html    # returns a chunk of HTML
  80
  81     This class also performs simple substitution on the effect, replacing
  82     `$effect_chance` with the move's actual effect chance.
  83
  84     Use `MoveEffectPropertyMap` for dict-like association proxies.
  85     """
  86
  87     def __init__(self, effect_column):
  88         self.effect_column = effect_column
  89
  90     def __get__(self, obj, cls):
  91         prop = getattr(obj.move_effect, self.effect_column)
  92         return _markdownify_effect_text(obj, prop)
  93
  94 class MoveEffectPropertyMap(MoveEffectProperty):
  95     """Similar to `MoveEffectProperty`, but works on dict-like association
  96     proxies.
  97     """
  98     def __get__(self, obj, cls):
  99         prop = getattr(obj.move_effect, self.effect_column)
 100         newdict = dict(prop)
 101         for key in newdict:
 102             newdict[key] = _markdownify_effect_text(obj, newdict[key])
 103         return newdict
 104
 105 class MarkdownColumn(sqlalchemy.types.TypeDecorator):
 106     """Generic SQLAlchemy column type for Markdown text.
 107
 108     Do NOT use this for move effects!  They need to know what move they belong
 109     to so they can fill in, e.g., effect chances.  Use the MoveEffectProperty
 110     property class above.
 111     """
 112     impl = sqlalchemy.types.Unicode
 113
 114     def process_bind_param(self, value, dialect):
 115         if value is None:
 116             return None
 117
 118         if not isinstance(value, basestring):
 119             # Can't assign, e.g., MarkdownString objects yet
 120             raise NotImplementedError
 121
 122         return unicode(value)
 123
 124     def process_result_value(self, value, dialect):
 125         if value is None:
 126             return None
 127
 128         return MarkdownString(value)