Moved container forms and attribute forms into admin. Moved AttributeFields and Entit...

[philo.git] / admin / forms / attributes.py

diff --git a/admin/forms/attributes.py b/admin/forms/attributes.py
new file mode 100644 (file)
index 0000000..fc77d0f
--- /dev/null
+++ b/admin/forms/attributes.py
@@ -0,0 +1,66 @@
+from django.contrib.contenttypes.generic import BaseGenericInlineFormSet
+from django.contrib.contenttypes.models import ContentType
+from django.forms.models import ModelForm
+from philo.models import Attribute
+
+
+__all__ = ('AttributeForm', 'AttributeInlineFormSet')
+
+
+class AttributeForm(ModelForm):
+       """
+       This class handles an attribute's fields as well as the fields for its value (if there is one.)
+       The fields defined will vary depending on the value type, but the fields for defining the value
+       (i.e. value_content_type and value_object_id) will always be defined. Except that value_object_id
+       will never be defined. BLARGH!
+       """
+       def __init__(self, *args, **kwargs):
+               super(AttributeForm, self).__init__(*args, **kwargs)
+               
+               # This is necessary because model forms store changes to self.instance in their clean method.
+               # Mutter mutter.
+               value = self.instance.value
+               self._cached_value_ct = self.instance.value_content_type
+               self._cached_value = value
+               
+               # If there is a value, pull in its fields.
+               if value is not None:
+                       self.value_fields = value.value_formfields()
+                       self.fields.update(self.value_fields)
+       
+       def save(self, *args, **kwargs):
+               # At this point, the cleaned_data has already been stored on self.instance.
+               
+               if self.instance.value_content_type != self._cached_value_ct:
+                       # The value content type has changed. Clear the old value, if there was one.
+                       if self._cached_value:
+                               self._cached_value.delete()
+                       
+                       # Clear the submitted value, if any.
+                       self.cleaned_data.pop('value', None)
+                       
+                       # Now create a new value instance so that on next instantiation, the form will
+                       # know what fields to add.
+                       if self.instance.value_content_type is not None:
+                               self.instance.value = self.instance.value_content_type.model_class().objects.create()
+               elif self.instance.value is not None:
+                       # The value content type is the same, but one of the value fields has changed.
+                       
+                       # Use construct_instance to apply the changes from the cleaned_data to the value instance.
+                       fields = self.value_fields.keys()
+                       if set(fields) & set(self.changed_data):
+                               self.instance.value.construct_instance(**dict([(key, self.cleaned_data[key]) for key in fields]))
+                               self.instance.value.save()
+               
+               return super(AttributeForm, self).save(*args, **kwargs)
+       
+       class Meta:
+               model = Attribute
+
+
+class AttributeInlineFormSet(BaseGenericInlineFormSet):
+       "Necessary to force the GenericInlineFormset to use the form's save method for new objects."
+       def save_new(self, form, commit):
+               setattr(form.instance, self.ct_field.get_attname(), ContentType.objects.get_for_model(self.instance).pk)
+               setattr(form.instance, self.ct_fk_field.get_attname(), self.instance.pk)
+               return form.save()
\ No newline at end of file