Created JSON field, descriptor, and formfield to handle json storage on models unifor...

[philo.git] / models / fields.py

diff --git a/models/fields.py b/models/fields.py
index 467befb..9483516 100644 (file)
--- a/models/fields.py
+++ b/models/fields.py
@@ -1,12 +1,46 @@
 from django.db import models
 from django.db import models

-from django.db.models import signals
-from django.core.exceptions import FieldError
-from philo.models.base import Entity
+from django import forms
+from django.core.exceptions import FieldError, ValidationError
+from django.utils import simplejson as json
+from django.utils.text import capfirst
+from philo.signals import entity_class_prepared
+from philo.validators import TemplateValidator, json_validator

 
 
 __all__ = ('AttributeField', 'RelationshipField')
 
 
 
 
 __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):
+               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
 class AttributeFieldDescriptor(object):
        def __init__(self, field):
                self.field = field


@@ -35,19 +69,25 @@ class AttributeFieldDescriptor(object):
                instance._removed_attribute_registry.append(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):
        
        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):
 
 
 class RelationshipFieldDescriptor(object):


@@ -81,16 +121,90 @@ class RelationshipFieldDescriptor(object):
                instance._removed_relationship_registry.append(self.field.key)
 
 
                instance._removed_relationship_registry.append(self.field.key)
 
 

-class RelationshipField(object):
-       def __init__(self, key):
+class RelationshipField(EntityProxyField):
+       descriptor_class = RelationshipFieldDescriptor
+       
+       def __init__(self, model, limit_choices_to=None, key=None, **kwargs):
+               super(RelationshipField, self).__init__(**kwargs)

                self.key = key
                self.key = key

+               self.model = model
+               if limit_choices_to is None:
+                       limit_choices_to = {}
+               self.limit_choices_to = limit_choices_to

        
        

-       def actually_contribute_to_class(self, sender, **kwargs):
-               setattr(sender, self.name, RelationshipFieldDescriptor(self))
+       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)
+
+
+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):
        
        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(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