Moved efficient QuerySetMappers into philo.utils and replaced them with a more comple...

[philo.git] / philo / models / base.py

diff --git a/philo/models/base.py b/philo/models/base.py
index 46e9ac5..0ab9b70 100644 (file)
--- a/philo/models/base.py
+++ b/philo/models/base.py
@@ -1,5 +1,3 @@
-from UserDict import DictMixin
-
 from django import forms
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
@@ -13,15 +11,19 @@ from mptt.models import MPTTModel, MPTTModelBase, MPTTOptions
 from philo.exceptions import AncestorDoesNotExist
 from philo.models.fields import JSONField
 from philo.signals import entity_class_prepared
-from philo.utils import ContentTypeRegistryLimiter, ContentTypeSubclassLimiter
+from philo.utils import ContentTypeRegistryLimiter, ContentTypeSubclassLimiter, AttributeMapper, TreeAttributeMapper
 from philo.validators import json_validator
 
 
 class Tag(models.Model):
+       """A simple, generic model for tagging."""
+       #: A CharField (max length 255) which contains the name of the tag.
        name = models.CharField(max_length=255)
+       #: A CharField (max length 255) which contains the tag's unique slug.
        slug = models.SlugField(max_length=255, unique=True)
        
        def __unicode__(self):
+               """Returns the value of the :attr:`name` field"""
                return self.name
        
        class Meta:
@@ -40,7 +42,7 @@ class Titled(models.Model):
                abstract = True
 
 
-#: An instance of :class:`ContentTypeRegistryLimiter` which is used to track the content types which can be related to by ForeignKeyValues and ManyToManyValues.
+#: An instance of :class:`ContentTypeRegistryLimiter` which is used to track the content types which can be related to by :class:`ForeignKeyValue`\ s and :class:`ManyToManyValue`\ s.
 value_content_type_limiter = ContentTypeRegistryLimiter()
 
 
@@ -258,35 +260,26 @@ class Attribute(models.Model):
        def __unicode__(self):
                return u'"%s": %s' % (self.key, self.value)
        
+       def set_value(self, value, value_class=JSONValue):
+               """Given a value and a value class, sets up self.value appropriately."""
+               if isinstance(self.value, value_class):
+                       val = self.value
+               else:
+                       if isinstance(self.value, models.Model):
+                               self.value.delete()
+                       val = value_class()
+               
+               val.set_value(value)
+               val.save()
+               
+               self.value = val
+               self.save()
+       
        class Meta:
                app_label = 'philo'
                unique_together = (('key', 'entity_content_type', 'entity_object_id'), ('value_content_type', 'value_object_id'))
 
 
-class QuerySetMapper(object, DictMixin):
-       def __init__(self, queryset, passthrough=None):
-               self.queryset = queryset
-               self.passthrough = passthrough
-       
-       def __getitem__(self, key):
-               try:
-                       value = self.queryset.get(key__exact=key).value
-               except ObjectDoesNotExist:
-                       if self.passthrough is not None:
-                               return self.passthrough.__getitem__(key)
-                       raise KeyError
-               else:
-                       if value is not None:
-                               return value.value
-                       return value
-       
-       def keys(self):
-               keys = set(self.queryset.values_list('key', flat=True).distinct())
-               if self.passthrough is not None:
-                       keys |= set(self.passthrough.keys())
-               return list(keys)
-
-
 class EntityOptions(object):
        def __init__(self, options):
                if options is not None:
@@ -314,10 +307,9 @@ class Entity(models.Model):
        
        attribute_set = generic.GenericRelation(Attribute, content_type_field='entity_content_type', object_id_field='entity_object_id')
        
-       @property
-       def attributes(self):
+       def get_attribute_mapper(self, mapper=AttributeMapper):
                """
-               Property that returns a dictionary-like object which can be used to retrieve related :class:`Attribute`\ s' values directly.
+               Returns a dictionary-like object which can be used to retrieve related :class:`Attribute`\ s' values directly.
 
                Example::
 
@@ -328,8 +320,8 @@ class Entity(models.Model):
                        u'eggs'
                
                """
-               
-               return QuerySetMapper(self.attribute_set.all())
+               return mapper(self)
+       attributes = property(get_attribute_mapper)
        
        class Meta:
                abstract = True
@@ -496,10 +488,9 @@ class TreeEntity(Entity, TreeModel):
        
        __metaclass__ = TreeEntityBase
        
-       @property
-       def attributes(self):
+       def get_attribute_mapper(self, mapper=None):
                """
-               Property that returns a dictionary-like object which can be used to retrieve related :class:`Attribute`\ s' values directly. If an attribute with a given key is not related to the :class:`Entity`, then the object will check the parent's attributes.
+               Returns a dictionary-like object which can be used to retrieve related :class:`Attribute`\ s' values directly. If an attribute with a given key is not related to the :class:`Entity`, then the object will check the parent's attributes.
 
                Example::
 
@@ -512,10 +503,13 @@ class TreeEntity(Entity, TreeModel):
                        u'eggs'
                
                """
-               
-               if self.parent:
-                       return QuerySetMapper(self.attribute_set.all(), passthrough=self.parent.attributes)
-               return super(TreeEntity, self).attributes
+               if mapper is None:
+                       if self.parent:
+                               mapper = TreeAttributeMapper
+                       else:
+                               mapper = AttributeMapper
+               return super(TreeEntity, self).get_attribute_mapper(mapper)
+       attributes = property(get_attribute_mapper)
        
        class Meta:
                abstract = True
\ No newline at end of file