django-eav2/managers.py
2010-09-08 12:10:47 +00:00

54 lines
2.1 KiB
Python

import re
from django.db import models
from .models import EavEntity
class EntityManager(models.Manager):
def filter(self, *args, **kwargs):
qs = self.get_query_set().filter(*args)
for lookup, value in kwargs.items():
lookups = self._filter_by_lookup(qs, lookup, value)
qs = qs.filter(**lookups)
return qs
def _filter_by_lookup(self, qs, lookup, value):
slugs = EavEntity.get_all_attribute_slugs_for_model(self.model)
fields = self.model._meta.get_all_field_names()
attributes = EavEntity.get_all_attributes_for_model(self.model)
config_cls = self._get_config_cls()
eav_prefix = config_cls.proxy_field_name
gr_name = config_cls.generic_relation_field_name
if not lookup.startswith("%s__" % eav_prefix):
return {lookup: value}
lookup = re.sub(r'^%s__' % eav_prefix, '', lookup)
# Sublookup will be None if there is no __ in the lookup
name, sublookup = (lookup.split('__', 1) + [None])[:2]
if name in slugs:
# EAV attribute (Attr instance linked to entity)
attribute = EavEntity.get_attribute_by_slug_for_model(self.model , name)
return self._filter_by_simple_schema(qs, lookup, sublookup, value, attribute)
else:
raise NameError('Cannot filter items by attributes: unknown '
'attribute "%s". Available fields: %s. '
'Available attribute: %s.' % (name,
', '.join(fields), ', '.join(slugs)))
def _filter_by_simple_schema(self, qs, lookup, sublookup, value, attribute):
config_cls = self._get_config_cls()
eav_prefix = config_cls.proxy_field_name
gr_name = config_cls.generic_relation_field_name
value_lookup = '%s__value_%s' % (gr_name, attribute.datatype)
if sublookup:
value_lookup = '%s__%s' % (value_lookup, sublookup)
return { value_lookup: value }
def _get_config_cls(self):
from .utils import EavRegistry
return EavRegistry.get_config_cls_for_model(self.model)