Follow pagination links on the LTI names and roles API responses

lms/services/lti_names_roles.py

@@ -5,11 +5,14 @@
 https://www.imsglobal.org/ltiadvantage
 """
 
-from typing import TypedDict
+import logging
+from typing import Any, TypedDict
 
 from lms.models import LTIRegistration
 from lms.services.ltia_http import LTIAHTTPService
 
+LOG = logging.getLogger(__name__)
+
 
 class Member(TypedDict):
     """Structure of the members returned by the name and roles LTI API."""
@@ -37,6 +40,8 @@ def get_context_memberships(
         lti_registration: LTIRegistration,
         service_url: str,
         resource_link_id: str | None = None,
+        max_pages: int = 10,
+        limit: int = 100,
     ) -> list[Member]:
         """
         Get the roster for a course or assignment.
@@ -45,12 +50,31 @@ def get_context_memberships(
         from a LTI launch parameter and is always linked to an specific context.
 
         Optionally, using the  same service_url the API allows to get the roster of an assignment identified by `resource_link_id`.
+
+        max_pages and limit control the default pagination limits.
         """
-        query = {}
+
+        query: dict[str, Any] = {"limit": limit}
         if resource_link_id:
             query["rlid"] = resource_link_id
 
-        response = self._ltia_service.request(
+        response = self._make_request(lti_registration, service_url, query)
+
+        members = response.json()["members"]
+
+        while response.links.get("next") and max_pages:
+            LOG.info("Fetching next page of members %s", response.links["next"]["url"])
+            response = self._make_request(
+                lti_registration, response.links["next"]["url"], query
+            )
+            members.extend(response.json()["members"])
+
+            max_pages -= 1
+
+        return members
+
+    def _make_request(self, lti_registration, service_url, query):
+        return self._ltia_service.request(
             lti_registration,
             "GET",
             service_url,
@@ -61,8 +85,6 @@ def get_context_memberships(
             params=query,
         )
 
-        return response.json()["members"]
-
 
 def factory(_context, request):
     return LTINamesRolesService(ltia_http_service=request.find_service(LTIAHTTPService))

tests/unit/lms/services/lti_names_roles_test.py

@@ -1,4 +1,4 @@
-from unittest.mock import sentinel
+from unittest.mock import Mock, call, sentinel
 
 import pytest
 
@@ -7,6 +7,8 @@
 
 class TestLTINameRolesServices:
     def test_get_context_memberships(self, svc, ltia_http_service, lti_registration):
+        ltia_http_service.request.return_value.links = {}
+
         memberships = svc.get_context_memberships(
             lti_registration, sentinel.service_url
         )
@@ -19,16 +21,62 @@ def test_get_context_memberships(self, svc, ltia_http_service, lti_registration)
             headers={
                 "Accept": "application/vnd.ims.lti-nrps.v2.membershipcontainer+json"
             },
-            params={},
+            params={"limit": 100},
         )
         assert (
             memberships
             == ltia_http_service.request.return_value.json.return_value["members"]
         )
 
+    def test_get_context_memberships_multiple_pages(
+        self, svc, ltia_http_service, lti_registration
+    ):
+        ltia_http_service.request.side_effect = [
+            Mock(
+                links={"next": {"url": sentinel.next_url}},
+                json=Mock(return_value={"members": [sentinel.member_1]}),
+            ),
+            Mock(
+                links={},
+                json=Mock(return_value={"members": [sentinel.member_2]}),
+            ),
+        ]
+
+        memberships = svc.get_context_memberships(
+            lti_registration, sentinel.service_url
+        )
+
+        ltia_http_service.request.assert_has_calls(
+            [
+                call(
+                    lti_registration,
+                    "GET",
+                    sentinel.service_url,
+                    scopes=LTINamesRolesService.LTIA_SCOPES,
+                    headers={
+                        "Accept": "application/vnd.ims.lti-nrps.v2.membershipcontainer+json"
+                    },
+                    params={"limit": 100},
+                ),
+                call(
+                    lti_registration,
+                    "GET",
+                    sentinel.next_url,
+                    scopes=LTINamesRolesService.LTIA_SCOPES,
+                    headers={
+                        "Accept": "application/vnd.ims.lti-nrps.v2.membershipcontainer+json"
+                    },
+                    params={"limit": 100},
+                ),
+            ]
+        )
+        assert memberships == [sentinel.member_1, sentinel.member_2]
+
     def test_get_context_memberships_with_resource_link_id(
         self, svc, ltia_http_service, lti_registration
     ):
+        ltia_http_service.request.return_value.links = {}
+
         memberships = svc.get_context_memberships(
             lti_registration, sentinel.service_url, sentinel.resource_link_id
         )
@@ -41,7 +89,7 @@ def test_get_context_memberships_with_resource_link_id(
             headers={
                 "Accept": "application/vnd.ims.lti-nrps.v2.membershipcontainer+json"
             },
-            params={"rlid": sentinel.resource_link_id},
+            params={"rlid": sentinel.resource_link_id, "limit": 100},
         )
         assert (
             memberships