djangoforms.py 文件源码

def get_form_field(self, **kwargs):
    """Return a Django form field appropriate for a blob property.

    This defaults to a forms.FileField instance when using Django 0.97
    or later.  For 0.96 this returns None, as file uploads are not
    really supported in that version.
    """
    if not hasattr(forms, 'FileField'):
      return None
    defaults = {'form_class': forms.FileField}
    defaults.update(kwargs)
    return super(BlobProperty, self).get_form_field(**defaults)