-__all__ = ('JSONAttribute', 'ForeignKeyAttribute', 'ManyToManyAttribute')
-
-
-class EntityProxyField(object):
- descriptor_class = None
-
- def __init__(self, *args, **kwargs):
- if self.descriptor_class is None:
- raise NotImplementedError('EntityProxyField subclasses must specify a descriptor_class.')
- self.verbose_name = kwargs.get('verbose_name', None)
- self.help_text = kwargs.get('help_text', None)
-
- def actually_contribute_to_class(self, sender, **kwargs):
- sender._entity_meta.add_proxy_field(self)
- 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
- if self.verbose_name is None and name:
- self.verbose_name = name.replace('_', ' ')
- entity_class_prepared.connect(self.actually_contribute_to_class, sender=cls)
- else:
- raise FieldError('%s instances can only be declared on Entity subclasses.' % self.__class__.__name__)
-
- def formfield(self, *args, **kwargs):
- raise NotImplementedError('EntityProxyField subclasses must implement a formfield method.')
-
- def value_from_object(self, obj):
- return getattr(obj, self.attname)
-
-
-class AttributeFieldDescriptor(object):
- def __init__(self, field):
- self.field = field
-
- def __get__(self, instance, owner):
- if instance:
- if self.field in instance._added_attribute_registry:
- return instance._added_attribute_registry[self.field]
- if self.field in instance._removed_attribute_registry:
- return None
- try:
- return instance.attributes[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):
- raise NotImplementedError('AttributeFieldDescriptor subclasses must implement a __set__ method.')
-
- def __delete__(self, instance):
- if self.field in instance._added_attribute_registry:
- del instance._added_attribute_registry[self.field]
- instance._removed_attribute_registry.append(self.field)
-
-
-class JSONAttributeDescriptor(AttributeFieldDescriptor):
- def __set__(self, instance, value):
- if self.field in instance._removed_attribute_registry:
- instance._removed_attribute_registry.remove(self.field)
- instance._added_attribute_registry[self.field] = value
-
-
-class ForeignKeyAttributeDescriptor(AttributeFieldDescriptor):
- def __set__(self, instance, value):
- if isinstance(value, (models.Model, type(None))):
- if self.field in instance._removed_attribute_registry:
- instance._removed_attribute_registry.remove(self.field)
- instance._added_attribute_registry[self.field] = 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 in instance._removed_attribute_registry:
- instance._removed_attribute_registry.remove(self.field)
- instance._added_attribute_registry[self.field] = value
- else:
- raise AttributeError('The \'%s\' attribute can only be set to a QuerySet.' % self.field.name)
-
-
-class AttributeField(EntityProxyField):
- def contribute_to_class(self, cls, name):
- super(AttributeField, self).contribute_to_class(cls, name)
- if self.key is None:
- self.key = name
-
- def set_attribute_value(self, attribute, value, value_class):
- if not isinstance(attribute.value, value_class):
- if isinstance(attribute.value, models.Model):
- attribute.value.delete()
- new_value = value_class()
- else:
- new_value = attribute.value
- new_value.value = value
- new_value.save()
- attribute.value = new_value
-
-
-class JSONAttribute(AttributeField):
- descriptor_class = JSONAttributeDescriptor
-
- def __init__(self, field_template=None, key=None, **kwargs):
- super(AttributeField, self).__init__(**kwargs)
- self.key = key
- if field_template is None:
- field_template = models.CharField(max_length=255)
- self.field_template = field_template
-
- 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)
-
- def value_from_object(self, obj):
- try:
- return getattr(obj, self.attname)
- except AttributeError:
- return None
-
- def set_attribute_value(self, attribute, value, value_class=None):
- if value_class is None:
- from philo.models.base import JSONValue
- value_class = JSONValue
- super(JSONAttribute, self).set_attribute_value(attribute, value, value_class)
-
-
-class ForeignKeyAttribute(AttributeField):
- descriptor_class = ForeignKeyAttributeDescriptor
-
- def __init__(self, model, limit_choices_to=None, key=None, **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 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):
- try:
- relobj = super(ForeignKeyAttribute, self).value_from_object(obj)
- except AttributeError:
- return None
- return getattr(relobj, 'pk', None)
-
- def set_attribute_value(self, attribute, value, value_class=None):
- if value_class is None:
- from philo.models.base import ForeignKeyValue
- value_class = ForeignKeyValue
- super(ForeignKeyAttribute, self).set_attribute_value(attribute, value, value_class)
-
-
-class ManyToManyAttribute(ForeignKeyAttribute):
- descriptor_class = ManyToManyAttributeDescriptor
-
- def formfield(self, form_class=forms.ModelMultipleChoiceField, **kwargs):
- return super(ManyToManyAttribute, self).formfield(form_class, **kwargs)
-
- def set_attribute_value(self, attribute, value, value_class=None):
- if value_class is None:
- from philo.models.base import ManyToManyValue
- value_class = ManyToManyValue
- super(ManyToManyAttribute, self).set_attribute_value(attribute, value, value_class)
-
-