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 syntax `[text]{type:identifier}`, e.g.,
   9 `[Eevee]{pokemon:eevee}`.  The actual code that parses these is in
  10 spline-pokedex.
  11 """
  12 from __future__ import absolute_import
  13
  14 import markdown
  15 import sqlalchemy.types
  16
  17 class MarkdownString(object):
  18     """Wraps a Markdown string.  Stringifies to the original text, but .as_html
  19     will return an HTML rendering.
  20
  21     To add extensions to the rendering (which is necessary for rendering links
  22     correctly, and which spline-pokedex does), you must append to this class's
  23     `markdown_extensions` list.  Yep, that's gross.
  24     """
  25
  26     markdown_extensions = ['extra']
  27
  28     def __init__(self, source_text):
  29         self.source_text = source_text
  30         self._as_html = None
  31
  32     def __unicode__(self):
  33         return self.source_text
  34
  35     def __str__(self):
  36         return unicode(self.source_text).encode()
  37
  38     def __html__(self):
  39         return self.as_html
  40
  41     @property
  42     def as_html(self):
  43         """Returns the string as HTML4."""
  44
  45         if self._as_html is not None:
  46             return self._as_html
  47
  48         md = markdown.Markdown(
  49             extensions=self.markdown_extensions,
  50             safe_mode='escape',
  51             output_format='xhtml1',
  52         )
  53
  54         self._as_html = md.convert(self.source_text)
  55
  56         return self._as_html
  57
  58     @property
  59     def as_text(self):
  60         """Returns the string in a plaintext-friendly form.
  61
  62         At the moment, this is just the original source text.
  63         """
  64         return self.source_text
  65
  66 def _markdownify_effect_text(move, effect_text):
  67     effect_text = effect_text.replace(
  68         u'$effect_chance',
  69         unicode(move.effect_chance),
  70     )
  71
  72     return MarkdownString(effect_text)
  73
  74 class MoveEffectProperty(object):
  75     """Property that wraps move effects.  Used like this:
  76
  77         MoveClass.effect = MoveEffectProperty('effect')
  78
  79         some_move.effect            # returns a MarkdownString
  80         some_move.effect.as_html    # returns a chunk of HTML
  81
  82     This class also performs simple substitution on the effect, replacing
  83     `$effect_chance` with the move's actual effect chance.
  84
  85     Use `MoveEffectPropertyMap` for dict-like association proxies.
  86     """
  87
  88     def __init__(self, effect_column):
  89         self.effect_column = effect_column
  90
  91     def __get__(self, obj, cls):
  92         prop = getattr(obj.move_effect, self.effect_column)
  93         return _markdownify_effect_text(obj, prop)
  94
  95 class MoveEffectPropertyMap(MoveEffectProperty):
  96     """Similar to `MoveEffectProperty`, but works on dict-like association
  97     proxies.
  98     """
  99     def __get__(self, obj, cls):
 100         prop = getattr(obj.move_effect, self.effect_column)
 101         newdict = dict(prop)
 102         for key in newdict:
 103             newdict[key] = _markdownify_effect_text(obj, newdict[key])
 104         return newdict
 105
 106 class MarkdownColumn(sqlalchemy.types.TypeDecorator):
 107     """Generic SQLAlchemy column type for Markdown text.
 108
 109     Do NOT use this for move effects!  They need to know what move they belong
 110     to so they can fill in, e.g., effect chances.  Use the MoveEffectProperty
 111     property class above.
 112     """
 113     impl = sqlalchemy.types.Unicode
 114
 115     def process_bind_param(self, value, dialect):
 116         if value is None:
 117             return None
 118
 119         if not isinstance(value, basestring):
 120             # Can't assign, e.g., MarkdownString objects yet
 121             raise NotImplementedError
 122
 123         return unicode(value)
 124
 125     def process_result_value(self, value, dialect):
 126         if value is None:
 127             return None
 128
 129         return MarkdownString(value)