From 2f879ccc8b99d8580f8d1270dc38b5681adf3887 Mon Sep 17 00:00:00 2001
From: David Gelvin <david.gelvin@gmail.com>
Date: Wed, 8 Sep 2010 17:51:56 +0000
Subject: [PATCH] New manager

---
 managers.py          | 95 +++++++++++++++++++++++---------------------
 tests/set_and_get.py |  2 +-
 utils.py             |  4 +-
 3 files changed, 53 insertions(+), 48 deletions(-)

diff --git a/managers.py b/managers.py
index 9afce03..1d3efbb 100644
--- a/managers.py
+++ b/managers.py
@@ -1,54 +1,57 @@
-import re
-
 from django.db import models
-from .models import EavEntity
+from .models import EavAttribute
+
+
 
 class EntityManager(models.Manager):
+    def expand_filter_string(self, model_cls, q_str, prefix='', extra_filters=None):
+        from .utils import EavRegistry
+        if not extra_filters:
+            extra_filters = {}
+        fields = q_str.split('__')
+
+        # Is it EAV?
+        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:
+            gr_field = config_cls.generic_relation_field_name
+            slug = fields[1]
+            datatype = EavAttribute.objects.get(slug=slug).datatype
+            extra_filter_key = '%s__%s__attribute__slug' % (prefix, gr_field)
+            extra_filters[extra_filter_key] = slug
+            fields[0] = "%s__value_%s" % (gr_field, datatype)
+            fields.pop(1)
+            return '__'.join(fields), extra_filters
+
+        # Is it not EAV, but also not another field?
+        try:
+            field_object, model, direct, m2m = model_cls._meta.get_field_by_name(fields[0])
+        except FieldDoesNotExist:
+            return q_str, extra_filters
+
+        # Is it a direct field?
+        if direct:
+            return q_str, extra_filters
+        else:
+        # It is a foreign key.
+            prefix = "%s__%s" % (prefix, fields[0]) if prefix else fields[0]
+            sub_q_str = '__'.join(fields[1:])
+            retstring, dictionary = self.expand_filter_string(field_object.model, sub_q_str, prefix, extra_filters)
+            return ("%s__%s" % (fields[0], retstring), dictionary)
+
     def filter(self, *args, **kwargs):
         qs = self.get_query_set().filter(*args)
+        cls = self.model
         for lookup, value in kwargs.items():
-            lookups = self._filter_by_lookup(qs, lookup, value)
-            qs = qs.filter(**lookups)
+            updated_lookup, extra_filters = self.expand_filter_string(cls, lookup)
+            extra_filters.update({updated_lookup: value})
+            qs = qs.filter(**extra_filters)
         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)
+    def exclude(self, *args, **kwargs):
+        qs = self.get_query_set().exclude(*args)
+        for lookup, value in kwargs.items():
+            lookups = self._filter_by_lookup(qs, lookup, value)
+            updated_lookup, extra_filters = self.expand_filter_string(cls, lookup)
+            extra_filters.update({updated_lookup: value})
+            qs = qs.exclude(**lookups)
+        return qs
diff --git a/tests/set_and_get.py b/tests/set_and_get.py
index baebed3..62ec222 100644
--- a/tests/set_and_get.py
+++ b/tests/set_and_get.py
@@ -157,7 +157,7 @@ class EavSetterAndGetterTests(TestCase):
         self.patient.save()
         self.assertEqual(Patient.objects.get(pk=self.patient.pk).eav.city,
                          'Tunis')
-    
+
         EavRegistry.unregister(Patient)
 
         class PatientEav(EavConfig):
diff --git a/utils.py b/utils.py
index b39dab3..6229e31 100644
--- a/utils.py
+++ b/utils.py
@@ -34,7 +34,9 @@ class EavRegistry(object):
             model
         """
         cls_id = get_unique_class_identifier(model_cls)
-        return EavRegistry.cache[cls_id]['config_cls']
+
+        if cls_id in EavRegistry.cache:
+            return EavRegistry.cache[cls_id]['config_cls']
 
 
     @staticmethod