Task - RBAC Authz - Implement taxonomy permissions

Task - RBAC Authz - Implement taxonomy permissions

Context

openedx-platform#38436 added authz permission checks for the object tag endpoints (ObjectTagOrgView) and the xblock outline handler. However, the taxonomy-related endpoints still rely entirely on legacy org-level roles to determine access. Users with authz-only course roles (e.g. course_editor without legacy CourseStaffRole) cannot view, browse, or interact with taxonomies anywhere in course authoring.

This affects any surface in Studio that calls taxonomy endpoints — the content tags drawer, the taxonomy management pages, tag import/export, and any other course authoring feature that lists or browses taxonomies.

This is a continuation of the work started in #38143.

Endpoint inventory

Endpoints called from frontend-app-authoring.

Object tag endpoints (already fixed in #38436)

Endpoint	Method	Called from	Status
/object_tags/{contentId}/	GET	Content tags drawer — load applied tags	✅ Fixed
/object_tags/{contentId}/	PUT	Content tags drawer — save tag changes	✅ Fixed
/object_tag_counts/{contentId}/	GET	Content tags drawer, course outline — tag count badge	✅ No auth checks (by design)
/object_tags/{courseId}/export/	GET	Course outline — export tags CSV	✅ Fixed (uses has_view_object_tags_access)

Taxonomy list and detail endpoints (affected)

Endpoint	Method	Called from	Permission layer	Status
/taxonomies/?enabled=true&org=X	GET	Content tags drawer (with org from content ID), taxonomy management page	UserOrgFilterBackend → get_user_orgs / get_admin_orgs	❌ Broken
/taxonomies/{pk}/	GET	Taxonomy detail page	TaxonomyObjectPermissions → oel_tagging.view_taxonomy → can_view_taxonomy	❌ Broken (org-scoped)
/taxonomies/{pk}/	PATCH	Taxonomy detail page — edit taxonomy	TaxonomyObjectPermissions → oel_tagging.change_taxonomy	❌ Likely broken
/taxonomies/{pk}/	DELETE	Taxonomy management page — delete taxonomy	TaxonomyObjectPermissions → oel_tagging.delete_taxonomy	❌ Likely broken

Taxonomy tags endpoints (affected)

Endpoint	Method	Called from	Permission layer	Status
/taxonomies/{pk}/tags/	GET	Content tags drawer (browse/search tags), taxonomy detail page (tag list)	TaxonomyTagsObjectPermissions → oel_tagging.list_tag → can_view_taxonomy	❌ Broken (org-scoped)
/taxonomies/{pk}/tags/	POST	Taxonomy detail page — create tag	TaxonomyTagsObjectPermissions → oel_tagging.add_tag	❌ Likely broken
/taxonomies/{pk}/tags/	PUT	Taxonomy detail page — update tag	TaxonomyTagsObjectPermissions → oel_tagging.change_tag	❌ Likely broken
/taxonomies/{pk}/tags/	DELETE	Taxonomy detail page — delete tag	TaxonomyTagsObjectPermissions → oel_tagging.delete_tag	❌ Likely broken

Taxonomy import/export endpoints (affected)

Endpoint	Method	Called from	Permission layer	Status
/taxonomies/import/	POST	Taxonomy management page — create taxonomy from import	TaxonomyObjectPermissions	❌ Likely broken
/taxonomies/{pk}/tags/import/	PUT	Taxonomy detail page — import tags	TaxonomyTagsObjectPermissions	❌ Likely broken
/taxonomies/{pk}/tags/import/plan/	PUT	Taxonomy detail page — preview import	TaxonomyTagsObjectPermissions	❌ Likely broken
/taxonomies/{pk}/export/	GET	Taxonomy detail page — export taxonomy	No auth (direct download URL)	⚠️ Needs investigation
/taxonomies/import/template.{ext}	GET	Taxonomy management page — download template	No auth	✅ Fine

Taxonomy org management endpoint (affected)

Endpoint	Method	Called from	Permission layer	Status
/taxonomies/{pk}/orgs/	PUT	Taxonomy detail page — manage org associations	oel_tagging.update_orgs	❌ Likely broken

Root cause

All "broken" endpoints share the same root cause: permission checks resolve the user's org membership via legacy roles (get_user_orgs, get_admin_orgs, is_org_user, is_org_admin). Authz-only users have no legacy roles, so these checks fail.

The key functions that need authz-aware paths:

• UserOrgFilterBackend.filter_queryset — taxonomy list filtering
• can_view_taxonomy — django-rules predicate used by multiple permission classes
• is_org_user / is_org_admin — underlying org membership checks

Design considerations

• These endpoints don't always have a course context available. The taxonomy management page calls them without any course/content reference. An authz path may need to use get_scopes_for_user_and_permission to resolve the user's orgs from their authz role assignments, or the frontend may need to pass a content ID where applicable (see companion frontend issue).
• The can_view_taxonomy predicate is the most impactful fix — it underpins view_taxonomy, list_tag, and is used by both TaxonomyObjectPermissions and TaxonomyTagsObjectPermissions.
• Write operations (PATCH, DELETE, POST on taxonomies/tags) may need separate authz permissions (e.g. courses.manage_taxonomies) beyond just org membership.
• Library tagging should be unaffected — non-course objects fall through to legacy permissions.

Start with UserOrgFilterBackend.filter_queryset and the can_view_taxonomy predicate, then trace is_org_user and is_org_admin through the taxonomy permission classes and listed endpoints. Determine how authz-only course roles should resolve organization access and whether write operations need separate permissions. Done means taxonomy viewing and management work for eligible authz-only users while library tagging retains its legacy behavior.