'Return a description of the registration form.
This decouples clients from the API definition:
if the API decides to modify the form, clients won\'t need
to be updated.
This is especially important for the registration form,
since different edx-platform installations might
collect different demographic information.
See `user_api.helpers.FormDescription` for examples
of the JSON-encoded form description.
Arguments:
request (HttpRequest)
Returns:
HttpResponse'

@method_decorator(ensure_csrf_cookie)
def get(self, request):

    form_desc = FormDescription('post', reverse('user_api_registration'))
    self._apply_third_party_auth_overrides(request, form_desc)
    custom_form = get_registration_extension_form()
    if custom_form:
        for field_name in self.DEFAULT_FIELDS:
            self.field_handlers[field_name](form_desc, required=True)
        for (field_name, field) in custom_form.fields.items():
            restrictions = {}
            if getattr(field, 'max_length', None):
                restrictions['max_length'] = field.max_length
            if getattr(field, 'min_length', None):
                restrictions['min_length'] = field.min_length
            field_options = getattr(getattr(custom_form, 'Meta', None), 'serialization_options', {}).get(field_name, {})
            field_type = field_options.get('field_type', FormDescription.FIELD_TYPE_MAP.get(field.__class__))
            if (not field_type):
                raise ImproperlyConfigured("Field    type    '{}'    not    recognized    for    registration    extension    field    '{}'.".format(field_type, field_name))
            form_desc.add_field(field_name, label=field.label, default=field_options.get('default'), field_type=field_options.get('field_type', FormDescription.FIELD_TYPE_MAP.get(field.__class__)), placeholder=field.initial, instructions=field.help_text, required=field.required, restrictions=restrictions, options=getattr(field, 'choices', None), error_messages=field.error_messages, include_default_option=field_options.get('include_default_option'))
        for field_name in self.EXTRA_FIELDS:
            if self._is_field_visible(field_name):
                self.field_handlers[field_name](form_desc, required=self._is_field_required(field_name))
    else:
        for field_name in self.field_order:
            if (field_name in self.DEFAULT_FIELDS):
                self.field_handlers[field_name](form_desc, required=True)
            elif self._is_field_visible(field_name):
                self.field_handlers[field_name](form_desc, required=self._is_field_required(field_name))
    return HttpResponse(form_desc.to_json(), content_type='application/json')
