Added generic relation from attribute values back to Attribute.
[philo.git] / models / fields.py
index 50df799..0c68858 100644 (file)
@@ -1,12 +1,13 @@
 from django.db import models
 from django import forms
-from django.core.exceptions import FieldError
+from django.core.exceptions import FieldError, ValidationError
+from django.utils import simplejson as json
 from django.utils.text import capfirst
-from philo.models.base import Entity
 from philo.signals import entity_class_prepared
+from philo.validators import TemplateValidator, json_validator
 
 
-__all__ = ('AttributeField', 'RelationshipField')
+__all__ = ('JSONAttribute', 'ForeignKeyAttribute', 'ManyToManyAttribute')
 
 
 class EntityProxyField(object):
@@ -23,6 +24,7 @@ class EntityProxyField(object):
                setattr(sender, self.attname, self.descriptor_class(self))
        
        def contribute_to_class(self, cls, name):
+               from philo.models.base import Entity
                if issubclass(cls, Entity):
                        self.name = name
                        self.attname = name
@@ -57,9 +59,7 @@ class AttributeFieldDescriptor(object):
                        raise AttributeError('The \'%s\' attribute can only be accessed from %s instances.' % (self.field.name, owner.__name__))
        
        def __set__(self, instance, value):
-               if self.field.key in instance._removed_attribute_registry:
-                       instance._removed_attribute_registry.remove(self.field.key)
-               instance._added_attribute_registry[self.field.key] = value
+               raise NotImplementedError('AttributeFieldDescriptor subclasses must implement a __set__ method.')
        
        def __delete__(self, instance):
                if self.field.key in instance._added_attribute_registry:
@@ -67,8 +67,42 @@ class AttributeFieldDescriptor(object):
                instance._removed_attribute_registry.append(self.field.key)
 
 
+class JSONAttributeDescriptor(AttributeFieldDescriptor):
+       def __set__(self, instance, value):
+               if self.field.key in instance._removed_attribute_registry:
+                       instance._removed_attribute_registry.remove(self.field.key)
+               instance._added_attribute_registry[self.field.key] = value
+
+
+class ForeignKeyAttributeDescriptor(AttributeFieldDescriptor):
+       def __set__(self, instance, value):
+               if isinstance(value, (models.Model, type(None))):
+                       if self.field.key in instance._removed_attribute_registry:
+                               instance._removed_attribute_registry.remove(self.field.key)
+                       instance._added_attribute_registry[self.field.key] = value
+               else:
+                       raise AttributeError('The \'%s\' attribute can only be set using existing Model objects.' % self.field.name)
+
+
+class ManyToManyAttributeDescriptor(AttributeFieldDescriptor):
+       def __set__(self, instance, value):
+               if isinstance(value, models.QuerySet):
+                       if self.field.key in instance._removed_attribute_registry:
+                               instance._removed_attribute_registry.remove(self.field.key)
+                       instance._added_attribute_registry[self.field.key] = value
+               else:
+                       raise AttributeError('The \'%s\' attribute can only be set to a QuerySet.' % self.field.name)
+
+
 class AttributeField(EntityProxyField):
-       descriptor_class = AttributeFieldDescriptor
+       def contribute_to_class(self, cls, name):
+               super(AttributeField, self).contribute_to_class(cls, name)
+               if self.key is None:
+                       self.key = name
+
+
+class JSONAttribute(AttributeField):
+       descriptor_class = JSONAttributeDescriptor
        
        def __init__(self, field_template=None, key=None, **kwargs):
                super(AttributeField, self).__init__(**kwargs)
@@ -77,69 +111,99 @@ class AttributeField(EntityProxyField):
                        field_template = models.CharField(max_length=255)
                self.field_template = field_template
        
-       def contribute_to_class(self, cls, name):
-               super(AttributeField, self).contribute_to_class(cls, name)
-               if self.key is None:
-                       self.key = name
-       
        def formfield(self, **kwargs):
                defaults = {'required': False, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
                defaults.update(kwargs)
                return self.field_template.formfield(**defaults)
-
-
-class RelationshipFieldDescriptor(object):
-       def __init__(self, field):
-               self.field = field
-       
-       def __get__(self, instance, owner):
-               if instance:
-                       if self.field.key in instance._added_relationship_registry:
-                               return instance._added_relationship_registry[self.field.key]
-                       if self.field.key in instance._removed_relationship_registry:
-                               return None
-                       try:
-                               return instance.relationships[self.field.key]
-                       except KeyError:
-                               return None
-               else:
-                       raise AttributeError('The \'%s\' attribute can only be accessed from %s instances.' % (self.field.name, owner.__name__))
        
-       def __set__(self, instance, value):
-               if isinstance(value, (models.Model, type(None))):
-                       if self.field.key in instance._removed_relationship_registry:
-                               instance._removed_relationship_registry.remove(self.field.key)
-                       instance._added_relationship_registry[self.field.key] = value
-               else:
-                       raise AttributeError('The \'%s\' attribute can only be set using existing Model objects.' % self.field.name)
-       
-       def __delete__(self, instance):
-               if self.field.key in instance._added_relationship_registry:
-                       del instance._added_relationship_registry[self.field.key]
-               instance._removed_relationship_registry.append(self.field.key)
+       def value_from_object(self, obj):
+               return getattr(obj, self.attname).value
 
 
-class RelationshipField(EntityProxyField):
-       descriptor_class = RelationshipFieldDescriptor
+class ForeignKeyAttribute(AttributeField):
+       descriptor_class = ForeignKeyAttributeDescriptor
        
        def __init__(self, model, limit_choices_to=None, key=None, **kwargs):
-               super(RelationshipField, self).__init__(**kwargs)
+               super(ForeignKeyAttribute, self).__init__(**kwargs)
                self.key = key
                self.model = model
                if limit_choices_to is None:
                        limit_choices_to = {}
                self.limit_choices_to = limit_choices_to
        
-       def contribute_to_class(self, cls, name):
-               super(RelationshipField, self).contribute_to_class(cls, name)
-               if self.key is None:
-                       self.key = name
-       
        def formfield(self, form_class=forms.ModelChoiceField, **kwargs):
                defaults = {'required': False, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
                defaults.update(kwargs)
                return form_class(self.model._default_manager.complex_filter(self.limit_choices_to), **defaults)
        
        def value_from_object(self, obj):
-               relobj = super(RelationshipField, self).value_from_object(obj)
-               return getattr(relobj, 'pk', None)
\ No newline at end of file
+               relobj = super(ForeignKeyAttribute, self).value_from_object(obj).value
+               return getattr(relobj, 'pk', None)
+
+
+class ManyToManyAttribute(AttributeField):
+       descriptor_class = ManyToManyAttributeDescriptor
+       #FIXME: Add __init__ and formfield methods
+
+
+class TemplateField(models.TextField):
+       def __init__(self, allow=None, disallow=None, secure=True, *args, **kwargs):
+               super(TemplateField, self).__init__(*args, **kwargs)
+               self.validators.append(TemplateValidator(allow, disallow, secure))
+
+
+class JSONFormField(forms.Field):
+       def clean(self, value):
+               try:
+                       return json.loads(value)
+               except Exception, e:
+                       raise ValidationError(u'JSON decode error: %s' % e)
+
+
+class JSONDescriptor(object):
+       def __init__(self, field):
+               self.field = field
+       
+       def __get__(self, instance, owner):
+               if instance is None:
+                       raise AttributeError # ?
+               
+               if self.field.name not in instance.__dict__:
+                       json_string = getattr(instance, self.field.attname)
+                       instance.__dict__[self.field.name] = json.loads(json_string)
+               
+               return instance.__dict__[self.field.name]
+       
+       def __set__(self, instance, value):
+               instance.__dict__[self.field.name] = value
+               setattr(instance, self.field.attname, json.dumps(value))
+       
+       def __delete__(self, instance):
+               del(instance.__dict__[self.field.name])
+               setattr(instance, self.field.attname, json.dumps(None))
+
+
+class JSONField(models.TextField):
+       def __init__(self, *args, **kwargs):
+               super(JSONField, self).__init__(*args, **kwargs)
+               self.validators.append(json_validator)
+       
+       def get_attname(self):
+               return "%s_json" % self.name
+       
+       def contribute_to_class(self, cls, name):
+               super(JSONField, self).contribute_to_class(cls, name)
+               setattr(cls, name, JSONDescriptor(self))
+       
+       def formfield(self, *args, **kwargs):
+               kwargs["form_class"] = JSONFormField
+               return super(JSONField, self).formfield(*args, **kwargs)
+
+
+try:
+       from south.modelsinspector import add_introspection_rules
+except ImportError:
+       pass
+else:
+       add_introspection_rules([], ["^philo\.models\.fields\.TemplateField"])
+       add_introspection_rules([], ["^philo\.models\.fields\.JSONField"])
\ No newline at end of file