Added helper function to ease response 'returns' for signal listeners
[philo.git] / models / base.py
index 6f23191..33c994c 100644 (file)
@@ -3,7 +3,10 @@ from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
 from django.utils import simplejson as json
 from django.core.exceptions import ObjectDoesNotExist
 from django.contrib.contenttypes import generic
 from django.utils import simplejson as json
 from django.core.exceptions import ObjectDoesNotExist
+from philo.exceptions import AncestorDoesNotExist
 from philo.utils import ContentTypeRegistryLimiter
 from philo.utils import ContentTypeRegistryLimiter
+from philo.signals import entity_class_prepared
+from philo.validators import json_validator
 from UserDict import DictMixin
 
 
 from UserDict import DictMixin
 
 
@@ -34,7 +37,7 @@ class Attribute(models.Model):
        entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID')
        entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
        key = models.CharField(max_length=255)
        entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID')
        entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
        key = models.CharField(max_length=255)
-       json_value = models.TextField(verbose_name='Value (JSON)', help_text='This value must be valid JSON.')
+       json_value = models.TextField(verbose_name='Value (JSON)', help_text='This value must be valid JSON.', validators=[json_validator])
        
        def get_value(self):
                return json.loads(self.json_value)
        
        def get_value(self):
                return json.loads(self.json_value)
@@ -52,6 +55,7 @@ class Attribute(models.Model):
        
        class Meta:
                app_label = 'philo'
        
        class Meta:
                app_label = 'philo'
+               unique_together = ('key', 'entity_content_type', 'entity_object_id')
 
 
 value_content_type_limiter = ContentTypeRegistryLimiter()
 
 
 value_content_type_limiter = ContentTypeRegistryLimiter()
@@ -71,8 +75,8 @@ class Relationship(models.Model):
        entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID')
        entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
        key = models.CharField(max_length=255)
        entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID')
        entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
        key = models.CharField(max_length=255)
-       value_content_type = models.ForeignKey(ContentType, related_name='relationship_value_set', limit_choices_to=value_content_type_limiter, verbose_name='Value type')
-       value_object_id = models.PositiveIntegerField(verbose_name='Value ID')
+       value_content_type = models.ForeignKey(ContentType, related_name='relationship_value_set', limit_choices_to=value_content_type_limiter, verbose_name='Value type', null=True, blank=True)
+       value_object_id = models.PositiveIntegerField(verbose_name='Value ID', null=True, blank=True)
        value = generic.GenericForeignKey('value_content_type', 'value_object_id')
        
        def __unicode__(self):
        value = generic.GenericForeignKey('value_content_type', 'value_object_id')
        
        def __unicode__(self):
@@ -80,6 +84,7 @@ class Relationship(models.Model):
        
        class Meta:
                app_label = 'philo'
        
        class Meta:
                app_label = 'philo'
+               unique_together = ('key', 'entity_content_type', 'entity_object_id')
 
 
 class QuerySetMapper(object, DictMixin):
 
 
 class QuerySetMapper(object, DictMixin):
@@ -102,7 +107,30 @@ class QuerySetMapper(object, DictMixin):
                return list(keys)
 
 
                return list(keys)
 
 
+class EntityOptions(object):
+       def __init__(self, options):
+               if options is not None:
+                       for key, value in options.__dict__.items():
+                               setattr(self, key, value)
+               if not hasattr(self, 'proxy_fields'):
+                       self.proxy_fields = []
+       
+       def add_proxy_field(self, proxy_field):
+               self.proxy_fields.append(proxy_field)
+
+
+class EntityBase(models.base.ModelBase):
+       def __new__(cls, name, bases, attrs):
+               new = super(EntityBase, cls).__new__(cls, name, bases, attrs)
+               entity_options = attrs.pop('EntityMeta', None)
+               setattr(new, '_entity_meta', EntityOptions(entity_options))
+               entity_class_prepared.send(sender=new)
+               return new
+
+
 class Entity(models.Model):
 class Entity(models.Model):
+       __metaclass__ = EntityBase
+       
        attribute_set = generic.GenericRelation(Attribute, content_type_field='entity_content_type', object_id_field='entity_object_id')
        relationship_set = generic.GenericRelation(Relationship, content_type_field='entity_content_type', object_id_field='entity_object_id')
        
        attribute_set = generic.GenericRelation(Attribute, content_type_field='entity_content_type', object_id_field='entity_object_id')
        relationship_set = generic.GenericRelation(Relationship, content_type_field='entity_content_type', object_id_field='entity_object_id')
        
@@ -114,6 +142,63 @@ class Entity(models.Model):
        def relationships(self):
                return QuerySetMapper(self.relationship_set)
        
        def relationships(self):
                return QuerySetMapper(self.relationship_set)
        
+       @property
+       def _added_attribute_registry(self):
+               if not hasattr(self, '_real_added_attribute_registry'):
+                       self._real_added_attribute_registry = {}
+               return self._real_added_attribute_registry
+       
+       @property
+       def _removed_attribute_registry(self):
+               if not hasattr(self, '_real_removed_attribute_registry'):
+                       self._real_removed_attribute_registry = []
+               return self._real_removed_attribute_registry
+       
+       @property
+       def _added_relationship_registry(self):
+               if not hasattr(self, '_real_added_relationship_registry'):
+                       self._real_added_relationship_registry = {}
+               return self._real_added_relationship_registry
+       
+       @property
+       def _removed_relationship_registry(self):
+               if not hasattr(self, '_real_removed_relationship_registry'):
+                       self._real_removed_relationship_registry = []
+               return self._real_removed_relationship_registry
+       
+       def save(self, *args, **kwargs):
+               super(Entity, self).save(*args, **kwargs)
+               
+               for key in self._removed_attribute_registry:
+                       self.attribute_set.filter(key__exact=key).delete()
+               del self._removed_attribute_registry[:]
+               
+               for key, value in self._added_attribute_registry.items():
+                       try:
+                               attribute = self.attribute_set.get(key__exact=key)
+                       except Attribute.DoesNotExist:
+                               attribute = Attribute()
+                               attribute.entity = self
+                               attribute.key = key
+                       attribute.value = value
+                       attribute.save()
+               self._added_attribute_registry.clear()
+               
+               for key in self._removed_relationship_registry:
+                       self.relationship_set.filter(key__exact=key).delete()
+               del self._removed_relationship_registry[:]
+               
+               for key, value in self._added_relationship_registry.items():
+                       try:
+                               relationship = self.relationship_set.get(key__exact=key)
+                       except Relationship.DoesNotExist:
+                               relationship = Relationship()
+                               relationship.entity = self
+                               relationship.key = key
+                       relationship.value = value
+                       relationship.save()
+               self._added_relationship_registry.clear()
+       
        class Meta:
                abstract = True
 
        class Meta:
                abstract = True
 
@@ -157,7 +242,7 @@ class TreeManager(models.Manager):
 class TreeModel(models.Model):
        objects = TreeManager()
        parent = models.ForeignKey('self', related_name='children', null=True, blank=True)
 class TreeModel(models.Model):
        objects = TreeManager()
        parent = models.ForeignKey('self', related_name='children', null=True, blank=True)
-       slug = models.SlugField()
+       slug = models.SlugField(max_length=255)
        
        def has_ancestor(self, ancestor):
                parent = self
        
        def has_ancestor(self, ancestor):
                parent = self
@@ -168,7 +253,9 @@ class TreeModel(models.Model):
                return False
        
        def get_path(self, root=None, pathsep='/', field='slug'):
                return False
        
        def get_path(self, root=None, pathsep='/', field='slug'):
-               if root is not None and self.has_ancestor(root):
+               if root is not None:
+                       if not self.has_ancestor(root):
+                               raise AncestorDoesNotExist(root)
                        path = ''
                        parent = self
                        while parent and parent != root:
                        path = ''
                        parent = self
                        while parent and parent != root:
@@ -192,7 +279,7 @@ class TreeModel(models.Model):
                abstract = True
 
 
                abstract = True
 
 
-class TreeEntity(TreeModel, Entity):
+class TreeEntity(Entity, TreeModel):
        @property
        def attributes(self):
                if self.parent:
        @property
        def attributes(self):
                if self.parent: