Builtin `poll_question` block rendering is broken

[kdmccormick]

The Problem

poll_question rendering seems broken (see screenshots below).

The Studio view shows an error which may be helpful:

We're having trouble rendering your component

Students will not be able to access this component. Re-edit your component to fix the error.

Error: 'PollBlockWithMixins' object has no attribute 'mako_template' 

Note: This is not xblock-poll, a.k.a. the poll component. This is the poll_question component, a former XModule which is defined in edx-platform.

Steps to reproduce

I found this in both master (using tutor dev & local) and Palm (using current-release.openedx.org).

• Go to a course in Studio

• In advanced settings, add "poll_question" to the advanced module list. Save.

• In the unit editor, add an Advanced->poll_question component.

• Author view:

  

• Edit view:

  

• Click "Publish" and then "View Live Version"

• Student view

  

[Agrendalath]

@kdmccormick, according to #26873, this XBlock never had a Studio editor. It was modified by changing the XML and re-importing the course.

I verified that this behavior in Nutmeg, as I didn't have an older instance around.

Theoretically, an editor can be easily added by:

1. Changing https://github.com/openedx/edx-platform/blob/355779983ee2be08358e6ca258e35013680df44a/webpack.builtinblocks.config.js#L84 to

"PollBlockEditor": [
  "./xmodule/js/src/xmodule.js",
  "./xmodule/js/src/raw/edit/metadata-only.js",
],

2. Adding the following code to PollBlock:

studio_js_module_name = "MetadataOnlyEditingDescriptor"
    mako_template = "widgets/metadata-edit.html"
    
    def studio_view(self, _context):
        """
        Return the studio view.
        """
        fragment = Fragment(self.runtime.service(self, 'mako').render_template(self.mako_template, self.get_context()))
        add_webpack_js_to_fragment(fragment, 'PollBlockEditor')
        shim_xmodule_js(fragment, self.studio_js_module_name)
        return fragment

3. Rebuilding the statics.

However, getting it to work properly would likely require creating a custom editor. That's because the answers have a bit unusual format: https://github.com/openedx/edx-platform/blob/355779983ee2be08358e6ca258e35013680df44a/xmodule/poll_block.py#L68-L73

cc: @ormsbee

[kdmccormick]

Makes sense @Agrendalath , thank you.

Given that this block is opt-in and a better Poll block exists, I don't think we need to make a Studio editor for it. It would be nice if Studio's error were more helpful (a la "There is no Studio editor for this component type. It may only be edited by exporting to XML.") but that's a different issue.