Retrieving the name of the class which powers a model field

Question

I'm handling some edge cases in some django code, and i'm hitting a problem that is only encountered when specific fields are involved.

I want to be able to detect the class that the Model is using for a field and depending upon the result drop into alternate logic.

I've tried to use get_internal_type() on the field instance but it just returns "BooleanField" and not the expected "ModifiedField"

The Custom Field Type:

class ModifiedField(models.BooleanField):
    def __init__(self, *args, **kwargs):
        kwargs['editable'] = False
        models.BooleanField.__init__(self, *args, **kwargs)

    def pre_save(self, model_instance, add):
        value = getattr(model_instance, self.attname)

        if add:
            return True
        elif value == 2:
            return False
        else:
            return True

Model:

class TemplateItem(models.Model):
    uuid = UUIDField(primary_key=True)
    name = models.CharField(null=False, blank=True, max_length=255)
    image = models.ImageField(_('Image'), upload_to=_template_image_upload_path,
                              storage=item_fs, null=True, blank=True)
    is_modified = ModifiedField()

score 1 · Accepted Answer · answered Mar 18 '13 at 15:23

1

Have you tried class._name_ ??

g = TemplateItem.objects.get(id=1)
g.__class__.__name__

answered Mar 18 '13 at 15:23

Silwest

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Actually the op is looking for a model's *field* class, not the class of the model itself. – bruno desthuilliers Mar 18 '13 at 15:25
Thank you, I feel kind of stupid now for not remembering I can do this! – Jharwood Mar 18 '13 at 15:33
@brunodesthuilliers is right I do want the field class, but if you have an instance of the class like I do, then it is simply a case of calling `instance.__class__.__name__` – Jharwood Mar 18 '13 at 15:34

bruno desthuilliers · Answer 2 · 2013-03-21T12:48:11.103

0

fld_cls = type(model_instance._meta.get_field(fieldname))

edited Mar 21 '13 at 12:48

answered Mar 18 '13 at 15:24

bruno desthuilliers

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Retrieving the name of the class which powers a model field

2 Answers2