Merge branch 'waldo' of git://github.com/melinath/philo into melinath
[philo.git] / models / fields.py
index 7f76b9c..50df799 100644 (file)
@@ -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