models/fields/__init__.py

   1 from django import forms
   2 from django.core.exceptions import ValidationError
   3 from django.core.validators import validate_slug
   4 from django.db import models
   5 from django.utils import simplejson as json
   6 from django.utils.text import capfirst
   7 from django.utils.translation import ugettext_lazy as _
   8 from philo.forms.fields import JSONFormField
   9 from philo.validators import TemplateValidator, json_validator
  10 #from philo.models.fields.entities import *
  11
  12
  13 class TemplateField(models.TextField):
  14         def __init__(self, allow=None, disallow=None, secure=True, *args, **kwargs):
  15                 super(TemplateField, self).__init__(*args, **kwargs)
  16                 self.validators.append(TemplateValidator(allow, disallow, secure))
  17
  18
  19 class JSONDescriptor(object):
  20         def __init__(self, field):
  21                 self.field = field
  22
  23         def __get__(self, instance, owner):
  24                 if instance is None:
  25                         raise AttributeError # ?
  26
  27                 if self.field.name not in instance.__dict__:
  28                         json_string = getattr(instance, self.field.attname)
  29                         instance.__dict__[self.field.name] = json.loads(json_string)
  30
  31                 return instance.__dict__[self.field.name]
  32
  33         def __set__(self, instance, value):
  34                 instance.__dict__[self.field.name] = value
  35                 setattr(instance, self.field.attname, json.dumps(value))
  36
  37         def __delete__(self, instance):
  38                 del(instance.__dict__[self.field.name])
  39                 setattr(instance, self.field.attname, json.dumps(None))
  40
  41
  42 class JSONField(models.TextField):
  43         default_validators = [json_validator]
  44
  45         def get_attname(self):
  46                 return "%s_json" % self.name
  47
  48         def contribute_to_class(self, cls, name):
  49                 super(JSONField, self).contribute_to_class(cls, name)
  50                 setattr(cls, name, JSONDescriptor(self))
  51                 models.signals.pre_init.connect(self.fix_init_kwarg, sender=cls)
  52
  53         def fix_init_kwarg(self, sender, args, kwargs, **signal_kwargs):
  54                 # Anything passed in as self.name is assumed to come from a serializer and
  55                 # will be treated as a json string.
  56                 if self.name in kwargs:
  57                         value = kwargs.pop(self.name)
  58
  59                         # Hack to handle the xml serializer's handling of "null"
  60                         if value is None:
  61                                 value = 'null'
  62
  63                         kwargs[self.attname] = value
  64
  65         def formfield(self, *args, **kwargs):
  66                 kwargs["form_class"] = JSONFormField
  67                 return super(JSONField, self).formfield(*args, **kwargs)
  68
  69
  70 class SlugMultipleChoiceField(models.Field):
  71         __metaclass__ = models.SubfieldBase
  72         description = _("Comma-separated slug field")
  73
  74         def get_internal_type(self):
  75                 return "TextField"
  76
  77         def to_python(self, value):
  78                 if not value:
  79                         return []
  80
  81                 if isinstance(value, list):
  82                         return value
  83
  84                 return value.split(',')
  85
  86         def get_prep_value(self, value):
  87                 return ','.join(value)
  88
  89         def formfield(self, **kwargs):
  90                 # This is necessary because django hard-codes TypedChoiceField for things with choices.
  91                 defaults = {
  92                         'widget': forms.CheckboxSelectMultiple,
  93                         'choices': self.get_choices(include_blank=False),
  94                         'label': capfirst(self.verbose_name),
  95                         'required': not self.blank,
  96                         'help_text': self.help_text
  97                 }
  98                 if self.has_default():
  99                         if callable(self.default):
 100                                 defaults['initial'] = self.default
 101                                 defaults['show_hidden_initial'] = True
 102                         else:
 103                                 defaults['initial'] = self.get_default()
 104
 105                 for k in kwargs.keys():
 106                         if k not in ('coerce', 'empty_value', 'choices', 'required',
 107                                                  'widget', 'label', 'initial', 'help_text',
 108                                                  'error_messages', 'show_hidden_initial'):
 109                                 del kwargs[k]
 110
 111                 defaults.update(kwargs)
 112                 form_class = forms.TypedMultipleChoiceField
 113                 return form_class(**defaults)
 114
 115         def validate(self, value, model_instance):
 116                 invalid_values = []
 117                 for val in value:
 118                         try:
 119                                 validate_slug(val)
 120                         except ValidationError:
 121                                 invalid_values.append(val)
 122
 123                 if invalid_values:
 124                         # should really make a custom message.
 125                         raise ValidationError(self.error_messages['invalid_choice'] % invalid_values)
 126
 127
 128 try:
 129         from south.modelsinspector import add_introspection_rules
 130 except ImportError:
 131         pass
 132 else:
 133         add_introspection_rules([], ["^philo\.models\.fields\.SlugMultipleChoiceField"])
 134         add_introspection_rules([], ["^philo\.models\.fields\.TemplateField"])
 135         add_introspection_rules([], ["^philo\.models\.fields\.JSONField"])