models/fields/__init__.py

   1 from django import forms
   2 from django.db import models
   3 from django.utils import simplejson as json
   4 from philo.forms.fields import JSONFormField
   5 from philo.validators import TemplateValidator, json_validator
   6 #from philo.models.fields.entities import *
   7
   8
   9 class TemplateField(models.TextField):
  10         def __init__(self, allow=None, disallow=None, secure=True, *args, **kwargs):
  11                 super(TemplateField, self).__init__(*args, **kwargs)
  12                 self.validators.append(TemplateValidator(allow, disallow, secure))
  13
  14
  15 class JSONDescriptor(object):
  16         def __init__(self, field):
  17                 self.field = field
  18
  19         def __get__(self, instance, owner):
  20                 if instance is None:
  21                         raise AttributeError # ?
  22
  23                 if self.field.name not in instance.__dict__:
  24                         json_string = getattr(instance, self.field.attname)
  25                         instance.__dict__[self.field.name] = json.loads(json_string)
  26
  27                 return instance.__dict__[self.field.name]
  28
  29         def __set__(self, instance, value):
  30                 instance.__dict__[self.field.name] = value
  31                 setattr(instance, self.field.attname, json.dumps(value))
  32
  33         def __delete__(self, instance):
  34                 del(instance.__dict__[self.field.name])
  35                 setattr(instance, self.field.attname, json.dumps(None))
  36
  37
  38 class JSONField(models.TextField):
  39         default_validators = [json_validator]
  40
  41         def get_attname(self):
  42                 return "%s_json" % self.name
  43
  44         def contribute_to_class(self, cls, name):
  45                 super(JSONField, self).contribute_to_class(cls, name)
  46                 setattr(cls, name, JSONDescriptor(self))
  47                 models.signals.pre_init.connect(self.fix_init_kwarg, sender=cls)
  48
  49         def fix_init_kwarg(self, sender, args, kwargs, **signal_kwargs):
  50                 if self.name in kwargs:
  51                         kwargs[self.attname] = json.dumps(kwargs.pop(self.name))
  52
  53         def formfield(self, *args, **kwargs):
  54                 kwargs["form_class"] = JSONFormField
  55                 return super(JSONField, self).formfield(*args, **kwargs)
  56
  57
  58 try:
  59         from south.modelsinspector import add_introspection_rules
  60 except ImportError:
  61         pass
  62 else:
  63         add_introspection_rules([], ["^philo\.models\.fields\.TemplateField"])
  64         add_introspection_rules([], ["^philo\.models\.fields\.JSONField"])