+class StringProperty(object):
+ def __init__(self, cls, stringclass, colname):
+ self.cls = cls
+ self.colname = colname
+ self.stringclass = stringclass
+
+ def __get__(self, instance, cls):
+ if instance:
+ return StringMapping(instance, self)
+ else:
+ return self
+
+ def __getitem__(self, lang):
+ return StringExpression(self, lang)
+
+ def __str__(self):
+ return '<StringDict %s.%s>' % (self.cls, self.colname)
+
+class StringMapping(collections.MutableMapping):
+ def __init__(self, instance, prop):
+ self.stringclass = prop.stringclass
+ self.instance = instance
+ self.strings = getattr(instance, prop.stringclass._attrname)
+ self.colname = prop.colname
+
+ def __len__(self):
+ return len(self.strings)
+
+ def __iter__(self):
+ return iter(self.strings)
+
+ def __contains__(self, lang):
+ return lang in self.strings
+
+ def __getitem__(self, lang):
+ return getattr(self.strings[lang], self.colname)
+
+ def __setitem__(self, lang, value):
+ try:
+ # Modifying an existing row
+ row = self.strings[lang]
+ except KeyError:
+ # We need do add a whole row for the language
+ row = self.stringclass()
+ row.object_id = self.instance.id
+ session = object_session(self.instance)
+ if isinstance(lang, basestring):
+ lang = session.query(Language).filter_by(
+ identifier=lang).one()
+ row.language = lang
+ self.strings[lang] = row
+ session.add(row)
+ return setattr(row, self.colname, value)
+
+ def __delitem__(self, lang):
+ raise NotImplementedError('Cannot delete a single string. '
+ 'Perhaps you wan to delete all of %s.%s?' %
+ (self.instance, self.stringclass._attrname)
+ )
+
+class StringExpression(ColumnOperators):
+ def __init__(self, prop, lang):
+ self.prop = prop
+ self.column = getattr(prop.stringclass, prop.colname)
+ self.lang_column = prop.stringclass._language_identifier
+ if isinstance(lang, basestring):
+ self.lang = lang
+ else:
+ self.lang = lang.identifier
+
+ def operate(self, op, *values, **kwargs):
+ return getattr(self.prop.cls, self.prop.stringclass._attrname).any(and_(
+ self.lang_column == self.lang,
+ op(self.column, *values, **kwargs),
+ ))
+
+class DefaultLangProperty(object):
+ def __init__(self, colname):
+ self.colname = colname
+
+ def __get__(self, instance, cls):
+ if instance:
+ return getattr(instance, self.colname)[default_lang]
+ else:
+ return getattr(cls, self.colname)[default_lang]
+
+ def __set__(self, instance, value):
+ getattr(instance, self.colname)[default_lang] = value
+
+ def __delete__(self, instance):
+ del getattr(instance, self.colname)[default_lang]
+