realize CourseAccessRoles for a user when an LMS user is linked to their external_user_key

common/djangoapps/student/api.py

@@ -1,7 +1,14 @@
+# pylint: disable=unused-import
+"""
+Python APIs exposed by the student app to other in-process apps.
+"""
+
+
 from django.contrib.auth import get_user_model
 from django.conf import settings
 
 from student.models_api import create_manual_enrollment_audit as _create_manual_enrollment_audit
+from student.models_api import get_course_access_role
 from student.models_api import get_course_enrollment as _get_course_enrollment
 from student.models_api import (
     ENROLLED_TO_ENROLLED as _ENROLLED_TO_ENROLLED,
@@ -13,6 +20,7 @@ from student.models_api import (
     ALLOWEDTOENROLL_TO_UNENROLLED as _ALLOWEDTOENROLL_TO_UNENROLLED,
     DEFAULT_TRANSITION_STATE as _DEFAULT_TRANSITION_STATE,
 )
+from student.roles import REGISTERED_ACCESS_ROLES as _REGISTERED_ACCESS_ROLES
 from openedx.core.djangoapps.site_configuration import helpers as configuration_helpers
 
 
@@ -90,3 +98,16 @@ def create_manual_enrollment_audit(
         enrollment,
         role
     )
+
+
+def get_access_role_by_role_name(role_name):
+    """
+    Get the concrete child class of the AccessRole abstract class associated with the string role_name
+    by looking in REGISTERED_ACCESS_ROLES. If there is no class associated with this name, return None.
+
+    Note that this will only return classes that are registered in _REGISTERED_ACCESS_ROLES.
+
+    Arguments:
+        role_name: the name of the role
+    """
+    return _REGISTERED_ACCESS_ROLES.get(role_name, None)

common/djangoapps/student/models_api.py

@@ -3,6 +3,7 @@ Provides Python APIs exposed from Student models.
 """
 import logging
 
+from student.models import CourseAccessRole as _CourseAccessRole
 from student.models import CourseEnrollment as _CourseEnrollment
 from student.models import ManualEnrollmentAudit as _ManualEnrollmentAudit
 from student.models import (
@@ -62,3 +63,33 @@ def get_phone_number(user_id):
         log.exception(exception)
         return None
     return student.phone_number or None
+
+
+def get_course_access_role(user, org, course_id, role):
+    """
+    Get a specific CourseAccessRole object. Return None if
+    it does not exist.
+
+    Arguments:
+        user: User object for the user who has access in a course
+        org: the org the course is in
+        course_id: the course_id of the CourseAccessRole
+        role: the role type of the role
+    """
+    try:
+        course_access_role = _CourseAccessRole.objects.get(
+            user=user,
+            org=org,
+            course_id=course_id,
+            role=role,
+        )
+    except _CourseAccessRole.DoesNotExist:
+        log.exception('No CourseAccessRole found for user_id=%(user_id)s, org=%(org)s, '
+                      'course_id=%(course_id)s, and role=%(role)s.', {
+                          'user': user.id,
+                          'org': org,
+                          'course_id': course_id,
+                          'role': role,
+                      })
+        return None
+    return course_access_role