Handle fieldset fields in the content rules control panel

[ericof]

Fields that a content rule condition or action declares in a non-default fieldset(...) were listed in @schema, but @controlpanels/content-rules did not read or write their values.

The edit and add forms of rule elements are not group forms, so plone.autoform puts those fields on form.groups instead of form.fields. The control panel only looked at form.fields, so:

• GET .../<rule>/action/<idx> (and condition/<idx>) omitted their values;
• PATCH silently ignored them;
• POST (adding an element) silently ignored them too. The issue doesn't mention this case, but it has the same cause.

Changes

• Fix (b81e887): a new include_fieldset_fields(form) helper adds the fields of all fieldsets to form.fields before values are read or applied, in add, get and update. It keeps the existing z3c.form path, so applyChanges, the ObjectModifiedEvent and the target_folder UUID handling behave as before.

• Refactor (266a19d), with no behavior change:

  • add, get, update and delete become small dispatchers on the URL path segments, with private helpers for each operation;
  • the CSRF, element lookup and edit form code is now shared;
  • added type hints and reST docstrings;
  • error messages use f-strings.

  The generated http-examples are unchanged.

Tests

test_controlpanels_content_rules.py registers a test-only rule action whose schema has an "advanced" fieldset, in its own layer, so the documented addable_actions don't change. It covers GET, POST and PATCH of fieldset fields. All three tests fail without the fix (KeyError: 'extra_title').

Full suite: 1409 tests, 7 failures. These are the pre-existing date/time failures I also get on main.

Closes #2016

[mister-roboto]

@ericof thanks for creating this Pull Request and helping to improve Plone!

TL;DR: Finish pushing changes, pass all other checks, then paste a comment:

@jenkins-plone-org please run jobs

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass, but it takes 30-60 min. Other CI checks are usually much faster and the Plone Jenkins resources are limited, so when done pushing changes and all other checks pass either start all Jenkins PR jobs yourself, or simply add the comment above in this PR to start all the jobs automatically.

Happy hacking!

[ericof]

@jenkins-plone-org please run jobs

[ericof]

@jenkins-plone-org please run jobs

[ericof]

News fragment is present, no idea why Mr. Roboto is complaining about it

[davisagli]

@ericof Sorry for my slow review. Looks good, and thank you.