MDL-74691 enrol_lti: allow omission of lineitems property in ags claim

The claim is valid with either or both of the URLs, so long as there's
at least one.

enrol/lti/classes/local/ltiadvantage/entity/ags_info.php

@@ -38,7 +38,7 @@ class ags_info {
     /** @var string Scope for posting scores.*/
     private const SCOPES_SCORES_POST = 'https://purl.imsglobal.org/spec/lti-ags/scope/score';
 
-    /** @var \moodle_url The service URL used to get/put lineitems*/
+    /** @var \moodle_url|null The service URL used to get/put lineitems, if supported*/
     private $lineitemsurl;
 
     /** @var \moodle_url|null The lineitemurl, which is only present when a single lineitem is supported.*/
@@ -56,11 +56,17 @@ class ags_info {
     /**
      * The ags_info constructor.
      *
-     * @param \moodle_url $lineitemsurl The service URL used to get/put lineitems.
+     * @param \moodle_url|null $lineitemsurl The service URL used to get/put lineitems, if supported.
      * @param \moodle_url|null $lineitemurl The lineitemurl, which is only present when a single lineitem is supported.
      * @param array $scopes The array of supported scopes for this service instance.
      */
-    private function __construct(\moodle_url $lineitemsurl, ?\moodle_url $lineitemurl, array $scopes) {
+    private function __construct(?\moodle_url $lineitemsurl, ?\moodle_url $lineitemurl, array $scopes) {
+
+        // Platforms may support just lineitemurl, just lineitemsurl or both. At least one of the two is required.
+        if (is_null($lineitemsurl) && is_null($lineitemurl)) {
+            throw new \coding_exception("Missing lineitem or lineitems URL");
+        }
+
         $this->lineitemsurl = $lineitemsurl;
         $this->lineitemurl = $lineitemurl;
         $this->validate_scopes($scopes);
@@ -69,12 +75,12 @@ class ags_info {
     /**
      * Factory method to create a new ags_info instance.
      *
-     * @param \moodle_url $lineitemsurl The service URL used to get/put lineitems.
+     * @param \moodle_url|null $lineitemsurl The service URL used to get/put lineitems, if supported.
      * @param \moodle_url|null $lineitemurl The lineitemurl, which is only present when a single lineitem is supported.
      * @param array $scopes The array of supported scopes for this service instance.
      * @return ags_info the object instance.
      */
-    public static function create(\moodle_url $lineitemsurl, ?\moodle_url $lineitemurl = null,
+    public static function create(?\moodle_url $lineitemsurl = null, ?\moodle_url $lineitemurl = null,
             array $scopes = []): ags_info {
         return new self($lineitemsurl, $lineitemurl, $scopes);
     }
@@ -110,11 +116,11 @@ class ags_info {
     }
 
     /**
-     * Get the url for querying line items.
+     * Get the url for querying line items, if supported.
      *
      * @return \moodle_url the url.
      */
-    public function get_lineitemsurl(): \moodle_url {
+    public function get_lineitemsurl(): ?\moodle_url {
         return $this->lineitemsurl;
     }
 

enrol/lti/classes/local/ltiadvantage/entity/resource_link.php

@@ -163,11 +163,11 @@ class resource_link {
     /**
      * Add grade service information to this resource_link instance.
      *
-     * @param \moodle_url $lineitemsurl the service URL for get/put of line items.
+     * @param \moodle_url|null $lineitemsurl the service URL for get/put of line items, if supported.
      * @param \moodle_url|null $lineitemurl the service URL if only a single line item is present in the platform.
      * @param string[] $scopes the string array of grade service scopes which may be used by the service.
      */
-    public function add_grade_service(\moodle_url $lineitemsurl, ?\moodle_url $lineitemurl = null, array $scopes = []) {
+    public function add_grade_service(?\moodle_url $lineitemsurl = null, ?\moodle_url $lineitemurl = null, array $scopes = []) {
         $this->gradeservice = ags_info::create($lineitemsurl, $lineitemurl, $scopes);
     }
 

enrol/lti/classes/local/ltiadvantage/repository/resource_link_repository.php

@@ -50,7 +50,7 @@ class resource_link_repository {
             $record->id
         );
 
-        if ($record->lineitemsservice) {
+        if ($record->lineitemsservice || $record->lineitemservice) {
             $scopes = [];
             if ($record->lineitemscope) {
                 $lineitemscopes = json_decode($record->lineitemscope);
@@ -65,7 +65,7 @@ class resource_link_repository {
                 $scopes[] = $record->scorescope;
             }
             $resourcelink->add_grade_service(
-                new \moodle_url($record->lineitemsservice),
+                $record->lineitemsservice ? new \moodle_url($record->lineitemsservice) : null,
                 $record->lineitemservice ? new \moodle_url($record->lineitemservice) : null,
                 $scopes
             );
@@ -112,7 +112,7 @@ class resource_link_repository {
             'ltideploymentid' => $resourcelink->get_deploymentid(),
             'resourceid' => $resourcelink->get_resourceid(),
             'lticontextid' => $resourcelink->get_contextid(),
-            'lineitemsservice' => $gradeservice ? $gradeservice->get_lineitemsurl()->out(false) : null,
+            'lineitemsservice' => null,
             'lineitemservice' => null,
             'lineitemscope' => null,
             'resultscope' => $gradeservice ? $gradeservice->get_resultscope() : null,
@@ -121,7 +121,10 @@ class resource_link_repository {
             'nrpsserviceversions' => $nrpservice ? json_encode($nrpservice->get_service_versions()) : null
         ];
 
-        if ($gradeservice  && ($lineitemurl = $gradeservice->get_lineitemurl())) {
+        if ($gradeservice && ($lineitemsurl = $gradeservice->get_lineitemsurl())) {
+            $record['lineitemsservice'] = $lineitemsurl->out(false);
+        }
+        if ($gradeservice && ($lineitemurl = $gradeservice->get_lineitemurl())) {
             $record['lineitemservice'] = $lineitemurl->out(false);
         }
         if ($gradeservice && ($lineitemscopes = $gradeservice->get_lineitemscope())) {

enrol/lti/classes/local/ltiadvantage/service/tool_launch_service.php

@@ -163,12 +163,12 @@ class tool_launch_service {
                 $context ? $context->get_id() : null
             );
         }
-        // AGS. If the lineitemsurl is missing, it means the tool has no access to the endpoint.
+        // Add the AGS configuration for the resource link.
         // See: http://www.imsglobal.org/spec/lti-ags/v2p0#assignment-and-grade-service-claim.
-        if ($launchdata->ags && $launchdata->ags['lineitems']) {
+        if ($launchdata->ags && (!empty($launchdata->ags['lineitems']) || !empty($launchdata->ags['lineitem']))) {
             $resourcelink->add_grade_service(
-                new \moodle_url($launchdata->ags['lineitems']),
+                !empty($launchdata->ags['lineitems']) ? new \moodle_url($launchdata->ags['lineitems']) : null,
-                isset($launchdata->ags['lineitem']) ? new \moodle_url($launchdata->ags['lineitem']) : null,
+                !empty($launchdata->ags['lineitem']) ? new \moodle_url($launchdata->ags['lineitem']) : null,
                 $launchdata->ags['scope']
             );
         }

enrol/lti/tests/local/ltiadvantage/entity/ags_info_test.php

@@ -286,6 +286,35 @@ class ags_info_test extends \advanced_testcase {
                     'exceptionmessage' => "Scope must be a string value"
                 ]
             ],
+            'Claim contains a single lineitem URL only with valid scopes' => [
+                'args' => [
+                    'lineitemsurl' => null,
+                    'lineitemurl' => new \moodle_url('https://platform.example.org/10/lineitems/4/lineitem'),
+                    'scopes' => [
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/score'
+                    ]
+                ],
+                'expectations' => [
+                    'valid' => true,
+                    'lineitemscope' => null,
+                    'scorescope' => 'https://purl.imsglobal.org/spec/lti-ags/scope/score',
+                    'resultscope' => null
+                ]
+            ],
+            'Claim contains no lineitems URL or lineitem URL' => [
+                'args' => [
+                    'lineitemsurl' => null,
+                    'lineitemurl' => null,
+                    'scopes' => [
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/score'
+                    ]
+                ],
+                'expectations' => [
+                    'valid' => false,
+                    'exception' => \coding_exception::class,
+                    'exceptionmessage' => "Missing lineitem or lineitems URL"
+                ]
+            ],
         ];
     }
 }

enrol/lti/tests/local/ltiadvantage/entity/resource_link_test.php

@@ -115,23 +115,96 @@ class resource_link_test extends \advanced_testcase {
     /**
      * Test confirming that a grade service instance can be added to the object instance.
      *
+     * @param array $args the array of method arguments
+     * @param array $expected the array of expectations
+     * @dataProvider add_grade_service_provider
      * @covers ::add_grade_service
      */
-    public function test_add_grade_service() {
+    public function test_add_grade_service(array $args, array $expected) {
         $reslink = resource_link::create('res-link-id-123', 24, 44);
         $this->assertNull($reslink->get_grade_service());
-        $reslink->add_grade_service(
+
-            new \moodle_url('https://platform.example.org/10/lineitems'),
+        if (!$expected['valid']) {
-            new \moodle_url('https://platform.example.org/10/lineitems/4/lineitem'),
+            $this->expectException($expected['exception']);
-            ['https://purl.imsglobal.org/spec/lti-ags/scope/lineitem']
+        }
-        );
+        $reslink->add_grade_service(...array_values($args));
         $gradeservice = $reslink->get_grade_service();
         $this->assertInstanceOf(ags_info::class, $gradeservice);
-        $this->assertEquals(new \moodle_url('https://platform.example.org/10/lineitems'),
+        $this->assertEquals($args['lineitemsurl'], $gradeservice->get_lineitemsurl());
-            $gradeservice->get_lineitemsurl());
+        $this->assertEquals($args['lineitemurl'], $gradeservice->get_lineitemurl());
-        $this->assertEquals(new \moodle_url('https://platform.example.org/10/lineitems/4/lineitem'),
+        $this->assertEquals($args['scope'], $gradeservice->get_scopes());
-            $gradeservice->get_lineitemurl());
+    }
-        $this->assertEquals(['https://purl.imsglobal.org/spec/lti-ags/scope/lineitem'], $gradeservice->get_scopes());
+
+    /**
+     * Data provider for testing the add_grade_service method.
+     *
+     * @return array the array of test case data.
+     */
+    public function add_grade_service_provider(): array {
+        return [
+            'Valid, both URLs, some scopes' => [
+                'args' => [
+                    'lineitemsurl' => new \moodle_url('https://platform.example.org/10/lineitems'),
+                    'lineitemurl' => new \moodle_url('https://platform.example.org/10/lineitems/4/lineitem'),
+                    'scope' => [
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/lineitem',
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/score'
+                    ]
+                ],
+                'expected' => [
+                    'valid' => true,
+                ]
+            ],
+            'Valid, only coupled line item URL, some scopes' => [
+                'args' => [
+                    'lineitemsurl' => null,
+                    'lineitemurl' => new \moodle_url('https://platform.example.org/10/lineitems/4/lineitem'),
+                    'scope' => [
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/score'
+                    ]
+                ],
+                'expected' => [
+                    'valid' => true,
+                ]
+            ],
+            'Valid, only decoupled line items URL, some scopes' => [
+                'args' => [
+                    'lineitemsurl' => new \moodle_url('https://platform.example.org/10/lineitems'),
+                    'lineitemurl' => null,
+                    'scope' => [
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/lineitem',
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/result.readonly',
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/score',
+                    ]
+                ],
+                'expected' => [
+                    'valid' => true,
+                ]
+            ],
+            'Valid, URLs without any scopes' => [
+                'args' => [
+                    'lineitemsurl' => new \moodle_url('https://platform.example.org/10/lineitems'),
+                    'lineitemurl' => new \moodle_url('https://platform.example.org/10/lineitems/4/lineitem'),
+                    'scope' => []
+                ],
+                'expected' => [
+                    'valid' => true,
+                ]
+            ],
+            'Invalid, missing both URLs' => [
+                'args' => [
+                    'lineitemsurl' => null,
+                    'lineitemurl' => null,
+                    'scope' => [
+                        'https://purl.imsglobal.org/spec/lti-ags/scope/lineitem'
+                    ]
+                ],
+                'expected' => [
+                    'valid' => false,
+                    'exception' => \coding_exception::class
+                ]
+            ],
+        ];
     }
 
     /**