Allow policies to be selected directly for reviewer tools actions

[eviljeff]

Fixes: mozilla/addons#15513

Description

Allow CinderPolicy to be selected directly for reviewer tools actions, rather then ReviewActionReasons (which were associated with a policy). placeholder values for policies can be filled in by the reviewer. With the waffle switch enabled, policies are available everywhere ReviewActionReasons were - except reviewer Reply action which has it's own email template and code path (it will be addressed in follow-ups)

Context

The (in theory) last piece of the work to replace ReviewActionReason - this took more work than expected as I didn't really consider the extra changes to show some policies for some actions and not others (e.g. we don't want the Approve policy shown for the Reject action).

Testing

First check that with the waffle switch off everything is as before:

• (You may have to create some ReviewActionReason instances in django admin)
• review action reasons can be selected for rejections, disables, and approves; cinder policies available for resolve abuse reports
• reasons are required for rejections and disables; not for approves
• the comment field is always visible; 4 rows high, and required

The enable the waffle switch

• in django admin sync the policies (needs Cinder API key in settings)
• in django enable expose in reviewer tools for some policies
  • the policies will need to have enforcement actions defined in Cinder. And text too to be useful.
  • policy text can have {PLACEHOLDER} values in them
  • if you decide to edit some, bear in mind you can't define AMO_REJECT_VERSION_ADDON for any policy that's used by moderators directly in Cinder - it has to be DISABLE_ADDON)
  • I already edited Sources -> Testing information required, so you can just expose that one in the reviewer tools
• CinderPolicy instances should be shown for approve, reject, disable, as well as resolve abuse reports as before.
• Any policies with text containing {XXX} should have an input field to fill in a value for XXX
• Comments should be optional
• If you check the email (in fake mail) it should contain the policy texts, with the placeholder values filled in.
• the policy text should also be shown in the reviewer tools addon/version history

Checklist

• Add #ISSUENUM at the top of your PR to an existing open issue in the mozilla/addons repository.
• Successfully verified the change locally.
• The change is covered by automated tests, or otherwise indicated why doing so is unnecessary/impossible.
• Add before and after screenshots (Only for changes that impact the UI).
• Add or update relevant docs reflecting the changes made.

[KevinMind]

Some comments on the code. I will try to verify tomorrow.

[KevinMind]

This is breaking by brain... label is an argument, that is set to obj and then the stringified version of that is set back to label?

[eviljeff]

hah, yeah - we use the same trick for a number of fields/widgets for reviewer forms - the field knows about the instances, but by the time it's passed to create_option in the widget the instance is unavailable, so we can't render html based on it. The trick is in WidgetRenderedModelMultipleChoiceField where rather than returning a string for the label that represents the instance, we return the instance object as the label; so we can then use it in create_option.

[KevinMind]

Merge conflicts?

[eviljeff]

Merge conflicts?

undoubtedly

[KevinMind]

Not directly related to this PR but still a bit of an annoying behavior. If you have an invalid form state and submit, the form refreshes and cinder placeholder fields are cleared. Would be great if they were persisted on reload.

[KevinMind]

LGTM 🚢

[eviljeff]

Not directly related to this PR but still a bit of an annoying behavior. If you have an invalid form state and submit, the form refreshes and cinder placeholder fields are cleared. Would be great if they were persisted on reload.

mmm, I didn't notice that, but I can see why that'd happen (they're not django form fields) I'll file a follow-up.

--edit mozilla/addons#15612