Use a class + mapper instead of dynamic declarative magic

This commit is contained in:
Petr Viktorin 2011-03-08 23:09:08 +02:00 committed by Eevee
parent b3c7689d41
commit d0d4d1aa96

View file

@ -25,7 +25,9 @@ from sqlalchemy.ext.declarative import (
declarative_base, declared_attr, DeclarativeMeta,
)
from sqlalchemy.ext.associationproxy import association_proxy
from sqlalchemy.orm import backref, eagerload_all, relation, class_mapper
from sqlalchemy.orm import (
backref, eagerload_all, relation, class_mapper, synonym, mapper,
)
from sqlalchemy.orm.session import Session
from sqlalchemy.orm.collections import attribute_mapped_collection
from sqlalchemy.sql import and_
@ -1770,52 +1772,53 @@ def makeTextTable(object_table, name_plural, name_singular, columns, lazy):
if safe_name == 'language':
safe_name = 'lang'
fields = {
safe_name + '_id': Column(Integer,
ForeignKey(object_table.id), primary_key=True, nullable=False,
info=dict(description="ID of the object this table represents")
tablename = object_table.__singlename__ + '_' + name_plural
singlename = object_table.__singlename__ + '_' + name_singular
class Strings(object):
__tablename__ = tablename
__singlename__ = singlename
for name, plural, column in columns:
column.name = name
table = Table(tablename, metadata,
Column(safe_name + '_id', Integer, ForeignKey(object_table.id),
primary_key=True, nullable=False),
Column('language_id', Integer, ForeignKey(Language.id),
primary_key=True, nullable=False),
*(column for name, plural, column in columns)
)
mapper(Strings, table,
properties={
"object_id": synonym(safe_name + '_id'),
"language": relation(
Language,
primaryjoin=table.c.language_id == Language.id,
),
'__tablename__': table.__singlename__ + '_' + name_plural,
'__singlename__': table.__singlename__ + '_' + name_singular,
'is_%s_table' % name_singular: True,
}
fields.update((name, col) for name, plural, col in columns)
name = table.__name__ + name_singular.capitalize()
# There are some dynamic things that can only be set at class
# creation time because of declarative metaclass magic.
# So create class dynamically.
Strings = type(name, (TableBase, LanguageSpecific), fields)
# Alias the described thing to 'object', to make meta stuff easier
Strings.object_id = getattr(Strings, safe_name + '_id')
},
)
# The relation to the object
setattr(table, name_plural, relation(
setattr(object_table, name_plural, relation(
Strings,
primaryjoin=(table.id == Strings.object_id),
primaryjoin=(object_table.id == Strings.object_id),
backref=safe_name,
collection_class=attribute_mapped_collection('language'),
lazy=lazy,
))
Strings.object = getattr(Strings, safe_name)
Strings.object_table = table
setattr(table, name_singular + '_table', Strings)
Strings.language = relation(
Language,
primaryjoin=Strings.language_id == Language.id,
)
# Link the tables themselves, so we can get to them
Strings.object_table = object_table
setattr(object_table, name_singular + '_table', Strings)
for colname, pluralname, column in columns:
# Provide a relation with all the names, and an English accessor
# for backwards compatibility
def scope(colname, pluralname, column):
def get_string(self):
def get_strings(self):
return dict(
(l, getattr(t, colname))
for l, t in getattr(self, name_plural).items()
@ -1823,16 +1826,16 @@ def makeTextTable(object_table, name_plural, name_singular, columns, lazy):
def get_english_string(self):
try:
return get_string(self)['en']
return get_strings(self)['en']
except KeyError:
raise AttributeError(colname)
setattr(table, pluralname, property(get_string))
setattr(table, colname, property(get_english_string))
setattr(object_table, pluralname, property(get_strings))
setattr(object_table, colname, property(get_english_string))
scope(colname, pluralname, column)
if colname == 'name':
table.name_table = Strings
object_table.name_table = Strings
return Strings