django-eav2/managers.py
2010-09-17 00:10:38 +03:00

78 lines
2.5 KiB
Python

from functools import wraps
from django.db import models
from .models import EavAttribute, EavValue
def eav_filter(func):
@wraps(func)
def wrapper(self, *args, **kwargs):
new_args = []
for arg in args:
if isinstance(arg, models.Q):
# modify Q objects (warning: recursion ahead)
new_args.append(expand_q_filters(arg, self.model))
new_kwargs = {}
for key, value in kwargs.items():
new_key, new_value = expand_eav_filter(self.model, key, value)
new_kwargs.update({new_key: new_value})
return func(self, *new_args, **new_kwargs).distinct()
return wrapper
def expand_q_filters(q, root_cls):
new_children = []
for qi in q.children:
if type(qi) is tuple:
# this child is a leaf node: in Q this is a 2-tuple of:
# (filter parameter, value)
key, value = expand_eav_filter(root_cls, *qi)
new_children.append(models.Q(**{key: value}))
else:
# this child is another Q node: recursify!
new_children.append(expand_q_filters(qi, root_cls))
q.children = new_children
return q
def expand_eav_filter(model_cls, key, value):
from .utils import EavRegistry
fields = key.split('__')
config_cls = EavRegistry.get_config_cls_for_model(model_cls)
if len(fields) > 1 and config_cls and \
fields[0] == config_cls.proxy_field_name:
slug = fields[1]
gr_name = config_cls.generic_relation_field_name
datatype = EavAttribute.objects.get(slug=slug).datatype
lookup = '__%s' % fields[2] if len(fields) > 2 else ''
kwargs = {'value_%s%s' % (datatype, lookup): value,
'attribute__slug': slug}
value = EavValue.objects.filter(**kwargs)
return '%s__in' % gr_name, value
try:
field, m, direct, m2m = model_cls._meta.get_field_by_name(fields[0])
except models.FieldDoesNotExist:
return key, value
if direct:
return key, value
else:
sub_key = '__'.join(fields[1:])
key, value = expand_eav_filter(field.model, sub_key, value)
return '%s__%s' % (fields[0], key), value
class EntityManager(models.Manager):
@eav_filter
def filter(self, *args, **kwargs):
return super(EntityManager, self).filter(*args, **kwargs)
@eav_filter
def exclude(self, *args, **kwargs):
return super(EntityManager, self).exclude(*args, **kwargs)