X-Git-Url: http://git.ithinksw.org/philo.git/blobdiff_plain/2f2aed7e371d11b021432124de8f9bdd436b0832..6523713debf3076d8bac93e3262bc589faee286d:/models/fields.py diff --git a/models/fields.py b/models/fields.py index 7f76b9c..50df799 100644 --- a/models/fields.py +++ b/models/fields.py @@ -1,54 +1,91 @@ from django.db import models -from django.db.models import signals -from django.core.exceptions import ObjectDoesNotExist, FieldError -from django.contrib.contenttypes.models import ContentType -from functools import partial -from philo.models.base import Attribute, Relationship, Entity +from django import forms +from django.core.exceptions import FieldError +from django.utils.text import capfirst +from philo.models.base import Entity +from philo.signals import entity_class_prepared __all__ = ('AttributeField', 'RelationshipField') +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): + 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.key in instance._added_attribute_registry: + return instance._added_attribute_registry[self.field.key] + if self.field.key in instance._removed_attribute_registry: + return None try: - return instance.attribute_set.get(key__exact=self.field.key).value - except ObjectDoesNotExist: + 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): - try: - attribute = instance.attribute_set.get(key__exact=self.field.key) - except ObjectDoesNotExist: - attribute = Attribute() - attribute.entity = instance - attribute.key = self.field.key - attribute.value = value - attribute.save() + 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 def __delete__(self, instance): - instance.attribute_set.filter(key__exact=self.field.key).delete() + if self.field.key in instance._added_attribute_registry: + del instance._added_attribute_registry[self.field.key] + instance._removed_attribute_registry.append(self.field.key) -class AttributeField(object): - def __init__(self, key): - self.key = key +class AttributeField(EntityProxyField): + descriptor_class = AttributeFieldDescriptor - def actually_contribute_to_class(self, sender, **kwargs): - setattr(sender, self.name, AttributeFieldDescriptor(self)) + 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 contribute_to_class(self, cls, name): - if issubclass(cls, Entity): - self.name = name - signals.class_prepared.connect(self.actually_contribute_to_class, sender=cls) - else: - raise FieldError('AttributeFields can only be declared on Entity subclasses.') + 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): @@ -57,40 +94,52 @@ class RelationshipFieldDescriptor(object): 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.relationship_set.get(key__exact=self.field.key).value - except ObjectDoesNotExist: + 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))): - try: - relationship = instance.relationship_set.get(key__exact=self.field.key) - except ObjectDoesNotExist: - relationship = Relationship() - relationship.entity = instance - relationship.key = self.field.key - relationship.value = value - relationship.save() + 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 \'%\' attribute can only be set using existing Model objects.' % self.field.name) + raise AttributeError('The \'%s\' attribute can only be set using existing Model objects.' % self.field.name) def __delete__(self, instance): - instance.relationship_set.filter(key__exact=self.field.key).delete() + 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) -class RelationshipField(object): - def __init__(self, key): - self.key = key +class RelationshipField(EntityProxyField): + descriptor_class = RelationshipFieldDescriptor - def actually_contribute_to_class(self, sender, **kwargs): - setattr(sender, self.name, RelationshipFieldDescriptor(self)) + def __init__(self, model, limit_choices_to=None, key=None, **kwargs): + super(RelationshipField, 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): - if issubclass(cls, Entity): - self.name = name - signals.class_prepared.connect(self.actually_contribute_to_class, sender=cls) - else: - raise FieldError('RelationshipFields can only be declared on Entity subclasses.') \ No newline at end of file + 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