How do you add hcaptcha to the registration form?

[mauritsvanrees]

I am trying this in Plone 5.2, Python 3.8.
The readme says you can add this in an XML model:

<field name="captcha" type="plone.formwidget.hcaptcha.HCaptchaWidget">
  <title>Solve Captcha</title>
  <description></description>
</field>

I think this needs to be HCaptchaField instead of a widget.

When I add this to userschema.xml in a GS profile and import it, I get a warning and the field is ignored:

INFO    [plone.app.users.browser.schemaeditor:78][waitress-0] Unsupported field: captcha (CaptchaField)

Looking further, I add a patch to add captcha to two lists in plone.app.users:

full_field = "plone.formwidget.hcaptcha.HCaptchaField"
if full_field not in schemaeditor.ALLOWED_FIELDS:
    schemaeditor.ALLOWED_FIELDS.append(full_field)
field_class = "HCaptchaField"
if field_class not in schemaeditor.field_type_mapping:
    schemaeditor.field_type_mapping[field_class] = "string"
logger.info("Added hcaptcha to allowed fields and mapping in plone.app.users")

With this I no longer get the warning about an unsupported field. But importing fails, because plone.supermodel does not support it:

Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 167, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 376, in publish_module
  Module ZPublisher.WSGIPublisher, line 271, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZPublisher.WSGIPublisher, line 63, in call_object
  Module Products.GenericSetup.tool, line 577, in manage_importSelectedSteps
  Module Products.GenericSetup.tool, line 375, in runImportStepFromProfile
  Module Products.GenericSetup.tool, line 1323, in _doRunImportStep
   - __traceback_info__: usersschema
  Module plone.app.users.setuphandlers, line 21, in import_schema
  Module plone.app.users.browser.schemaeditor, line 136, in applySchema
  Module plone.app.users.browser.schemaeditor, line 178, in get_ttw_edited_schema
  Module plone.app.users.browser.schemaeditor, line 275, in load_ttw_schema
  Module plone.supermodel, line 37, in loadString
  Module plone.supermodel.parser, line 78, in parse
plone.supermodel.parser.SupermodelParseError: Field type plone.formwidget.hcaptcha.HCaptchaField specified for field captcha is not supported
  File "<unknown>", line 79
  File "/Users/maurits/shared-eggs/cp38/plone.supermodel-1.6.5-py3.8.egg/plone/supermodel/parser.py", line 72, in parse
    return _parse(source, policy)
  File "/Users/maurits/shared-eggs/cp38/plone.supermodel-1.6.5-py3.8.egg/plone/supermodel/parser.py", line 161, in _parse
    readField(
  File "/Users/maurits/shared-eggs/cp38/plone.supermodel-1.6.5-py3.8.egg/plone/supermodel/parser.py", line 121, in readField
    raise ValueError(

The zcml of plone.formwidget.hcaptcha does get loaded, and it has some code for supermodel.

In the TTW schema editor (the member-fields view) no options for adding a captcha are visible either. I suppose this is also due to some missing supermodel/schemaeditor integration.

Does anyone know what is missing? Maybe someone has a patch lying around already?

[fredvd]

The hacaptcha code is 1:1 taken from the recaptcha addon And then adapted. So any issues here will also be valid for plone.formwidget.recaptcha.