New version of mentoring block that supports explicit steps

[itsjeyd]

This PR introduces two new blocks and enables support for viewing and editing them in Studio. One of the blocks is a new version of MentoringBlock that supports explicit steps, the other one is a block that represents a step:

• The new mentoring block only allows step blocks (any number) and mentoring-wide messages as direct children.
• The step block hosts all blocks that can not be added to new mentoring block (MCQ, MRQ, Long Answer, etc.)

Acceptance criteria

Studio integration:

• Make it possible to add new mentoring block to unit
• Make it possible to add step blocks
• Make it possible to edit step blocks
• Make it possible to remove step blocks
• Make it possible to add step contents
• Previews at mentoring and step levels should function properly
• inner blocks should not have a studio header (small glitch: at mentoring level, HTML block still has a header)
• inner blocks should look more or less the same as they would in LMS
• inner blocks should have no obvious styling glitches and pass other common-sense checks

Testing

1. Enable new mentoring block for a course in Studio by adding pb-mentoring to advanced modules.
2. Add new mentoring block to a (new or existing) unit by choosing "Mentoring Questions (with explicit steps)" from the list of "Advanced" blocks.
3. Click "View" to edit the components of the block. Observe that the options for blocks to add are restricted to step and message blocks.
4. Add a step block.
5. Click "View" to edit the components of the block. Observe that the options for blocks to add include all relevant blocks that can not be added to the top level of the new mentoring block.
6. Try adding and removing a few components to/from the step block.
7. On the previous (mentoring) level, click "Edit" to change e.g. the title of the step block.
8. Click the trash icon to remove the step block.

[antoviaque]

Can we make this a block specifically for handling steps, rather than a copy of the all-encompassing mentoring block? Ie maybe StepManager or StepBuilder?

I haven't looked closely, but it seem there is currently a lot of duplicated code with mentoring, currently? Imho we should only duplicate code we expect to be able to remove from Mentoring once we remove the assessments from there, to handle it exclusively with steps in StepBuilder. Can the rest of the duplicated code be removed or factorized? Otherwise maintaining twice the "almost the same code" is not going to be fun.

[itsjeyd]

@antoviaque Thanks for the feedback! I DRYed out the changeset based on your suggestions (removed most of the duplicate code and factored the remaining code that was shared between the two mentoring blocks out into a shared superclass).

[antoviaque]

@itsjeyd Thanks! Definitely better : )

[e-kolpakov]

@itsjeyd please use StudioContainerWithNestedXBlocksMixin - it would look something like that:

context['wrap_children'] = {
     'head': u'<div class="mentoring">',
     'tail': u'</div>'
}
fragment = super(MentoringWithExplicitStepsBlock, self).author_edit_view(context)
fragment.add_content(loader.render_template('templates/html/mentoring_url_name.html', {
        "url_name": self.url_name
 }))
 # css and js stuff

mentoring_edit.js is mostly not needed, except for ProblemBuilderUtil.transformClarifications(element); Not sure what does it do - @bradenmacdonald - some hint on that? Anyway, if you still need it, it would be better to have a new mentoring_with_steps_edit.js with the following contents:

function MentoringWithStepsEdit(runtime, element) {
    ProblemBuilderUtil.transformClarifications(element);
    StudioEditableXBlockMixin(runtime, element);
}

UPD: Actually, since MentoringWithSteps is only concerned about steps and steps does transformClarifications it might not be needed

[bradenmacdonald]

transformClarifications is important - it parses the text/html content and injects the HTML needed for #44

[e-kolpakov]

@itsjeyd There're some glitches of various severity and complexity:

• "url_name for linking to this mentoring question set ..." used to be italicized, now it's not (now = in mentoring with steps)
• Adding Steps and messages does not work - you've forgot to add CATEGORY constants
• Might be a good idea to add some padding in preview view (though there aren't any in old mentoring, so if this takes more than 5 minutes it's ok to ignore it for now)
• Multiple messages of the same type are allowed - should only allow one; xblock-utils does not support single-instance-per-boilerplate yet, so use the approach in old mentoring - probably in mentoring_edit.js
• Rebase needed
• Message hints used to be italicized and have smaller font in old mentoring:
  

Overall - looks like you've forgot to add mentoring-step and pb-mentoring to last rule in problem-builder-edit.css

[itsjeyd]

@e-kolpakov As discussed in the hangout:

• reverted answer.css
• renamed lonely_step to lonely_child
• moved sibling implementations for to subclasses of EnumerableChildMixin and added a note about providing a default implementation in the future

[itsjeyd]

@e-kolpakov FYI: I squashed the commits before rebasing but did preserve a copy of them just in case.

[e-kolpakov]

@itsjeyd 👍 conditional the build passes.