What is wrong with my django's model field ?

Question

I am trying to do a PhoneField that convert the value as a standardized value.

In this case, I want to use this clean method.

def clean(self):
    phone = self.cleaned_data.get('phone')

    # Is it already standardized ?
    if phone.startswith('+'):
      mo = re.search(r'^\+\d{2,3}\.\d{9,11}$', phone)

      if not mo:
        raise forms.ValidationError(_(u'Vous devez entrer un numéro de téléphone. (+33.389520638 ou 0389520638).'))
      else:
        return phone

    # If not, it must be a french number.
    phone = re.sub("\D", "", phone) # Suppression des caractères séparateurs

    mo = re.search(r'^\d{10}$', phone) # Numéro à 10 chiffres
    if not mo:
        raise forms.ValidationError(_(u'Vous devez entrer un numéro de téléphone. (+33.389520638 ou 0389520638).'))
    else:
        phone = mo.group()[-9:]

    return u'+33.%s' % phone

If I use it in a form, it works well. But I would like to use it as a form field.

I tried to do like that :

EMPTY_VALUES = (None, '')

class PhoneInput (forms.TextInput):
    def render(self, name, value, attrs=None):
        if value not in EMPTY_VALUES:
            value = phone_render(value)
        else:
            value = None

        return super(PhoneInput, self).render(name, value, attrs)

class PhoneField(models.CharField):
    widget = PhoneInput

    def __init__(self, *args, **kwargs):
        kwargs['max_length'] = 16
        super(PhoneField, self).__init__(*args, **kwargs)

    def get_internal_type(self):
        return "CharField"

    def clean(self, value):
        phone = super(PhoneField, self).clean(value)

        # Le numéro contient-il un indicatif ?
        if phone.startswith('+'):
          mo = re.search(r'^\+\d{2,3}\.\d{9,11}$', phone)

          if not mo:
            raise forms.ValidationError(_(u'Vous devez entrer un numéro de téléphone. (+33.389520638 ou 0389520638).'))
          else:
            return phone

        # Pas d'indicatif : on est en France par défaut
        phone = re.sub("\D", "", phone) # Suppression des caractères séparateurs

        mo = re.search(r'^\d{10}$', phone) # Numéro à 10 chiffres
        if not mo:
            raise forms.ValidationError(_(u'Vous devez entrer un numéro de téléphone. (+33.389520638 ou 0389520638).'))
        else:
            phone = mo.group()[-9:]

        return u'+33.%s' % phone

But the clean method is never called. Can you help me ?

Answer 1

You are mixing up the model fields and form fields.

Form Fields need to be first defined and then corresponding model Fields need to be asked to use those form fields for a model form.

See specifying-the-form-field-for-a-model-field documentation

Basically you need to define a method called formfield on the model field

def formfield(self, **kwargs):
    # This is a fairly standard way to set up some defaults
    # while letting the caller override them.
    defaults = {'form_class': MyFormField}
    defaults.update(kwargs)
    return super(HandField, self).formfield(**defaults)

The Field that you have created above, has a clean method, that is a requirement for a form field, not a model field

So, now you should define a form field (the one you have defined, except extend it from forms.CharField, not models.CharField) and then define a model field, as per model field creation definitions, and include the method like above.

Alternatively and simplistically, you could just choose to define a form field, and in the model form, override the default form field of this particular modelfield. (Altho' in this case validation doesnt take place unless data is entered from that modelform)

Answer 2

Here is how I fixed it using becomingGuru help :)

 class PhoneFormField(forms.CharField):
     widget = PhoneInput

     def clean(self, value):
         phone = super(PhoneFormField, self).clean(value)

         # Le numéro contient-il un indicatif ?
         if phone.startswith('+'):
           mo = re.search(r'^\+\d{2,3}\.\d{9,11}$', phone)

           if not mo:
             raise forms.ValidationError(_(u'Vous devez entrer un numéro de téléphone. (+33.389520638 ou 0389520638).'))
           else:
             return phone

         # Pas d'indicatif : on est en France par défaut
         phone = re.sub("\D", "", phone) # Suppression des caractères séparateurs

         mo = re.search(r'^\d{10}$', phone) # Numéro à 10 chiffres
         if not mo:
             raise forms.ValidationError(_(u'Vous devez entrer un numéro de téléphone. (+33.389520638 ou 0389520638).'))
         else:
             phone = mo.group()[-9:]

         return u'+33.%s' % phone

 class PhoneField(models.CharField):
     def __init__(self, *args, **kwargs):
         kwargs['max_length'] = 16
         super(PhoneField, self).__init__(*args, **kwargs)

     def get_internal_type(self):
         return "CharField"

     def formfield(self, form_class=PhoneFormField, **kwargs):
         return super(PhoneField, self).formfield(form_class=form_class, **kwargs)

Thank you for your help.