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