MDL-62140 core_privacy: add helper functions to add system/user context

privacy/classes/local/request/contextlist.php

@@ -61,6 +61,46 @@ class contextlist extends contextlist_base {
         return $this;
     }
 
+    /**
+     * Adds the system context.
+     *
+     * @return $this
+     */
+    public function add_system_context() : contextlist {
+        return $this->add_from_sql(SYSCONTEXTID, []);
+    }
+
+    /**
+     * Adds the user context for a given user.
+     *
+     * @param int $userid
+     * @return $this
+     */
+    public function add_user_context(int $userid) : contextlist {
+        $sql = "SELECT DISTINCT ctx.id
+                  FROM {context} ctx
+                 WHERE ctx.contextlevel = :contextlevel
+                   AND ctx.instanceid = :instanceid";
+        return $this->add_from_sql($sql, ['contextlevel' => CONTEXT_USER, 'instanceid' => $userid]);
+    }
+
+    /**
+     * Adds the user contexts for given users.
+     *
+     * @param array $userids
+     * @return $this
+     */
+    public function add_user_contexts(array $userids) : contextlist {
+        global $DB;
+
+        list($useridsql, $useridparams) = $DB->get_in_or_equal($userids, SQL_PARAMS_NAMED);
+        $sql = "SELECT DISTINCT ctx.id
+                  FROM {context} ctx
+                 WHERE ctx.contextlevel = :contextlevel
+                   AND ctx.instanceid $useridsql";
+        return $this->add_from_sql($sql, ['contextlevel' => CONTEXT_USER] + $useridparams);
+    }
+
     /**
      * Sets the component for this contextlist.
      *

privacy/tests/contextlist_test.php

@@ -37,6 +37,13 @@ use \core_privacy\local\request\contextlist;
  */
 class contextlist_test extends advanced_testcase {
 
+    /**
+     * Runs before each test is performed.
+     */
+    public function setUp() {
+        $this->resetAfterTest();
+    }
+
     /**
      * Ensure that valid SQL results in the relevant contexts being added.
      */
@@ -52,4 +59,51 @@ class contextlist_test extends advanced_testcase {
 
         $this->assertCount(count($allcontexts), $uit);
     }
+
+    /**
+     * Ensure that valid system context id is added.
+     */
+    public function test_add_system_context() {
+        $cl = new contextlist();
+        $cl->add_system_context();
+
+        $this->assertCount(1, $cl);
+
+        foreach ($cl->get_contexts() as $context) {
+            $this->assertEquals(SYSCONTEXTID, $context->id);
+        }
+    }
+
+    /**
+     * Ensure that a valid user context id is added.
+     */
+    public function test_add_user_context() {
+        $user = $this->getDataGenerator()->create_user();
+
+        $cl = new contextlist();
+        $cl->add_user_context($user->id);
+
+        $this->assertCount(1, $cl);
+
+        foreach ($cl->get_contexts() as $context) {
+            $this->assertEquals(\context_user::instance($user->id)->id, $context->id);
+        }
+    }
+
+    /**
+     * Ensure that valid user contexts are added.
+     */
+    public function test_add_user_contexts() {
+        $user1 = $this->getDataGenerator()->create_user();
+        $user2 = $this->getDataGenerator()->create_user();
+
+        $cl = new contextlist();
+        $cl->add_user_contexts([$user1->id, $user2->id]);
+
+        $this->assertCount(2, $cl);
+
+        $contexts = $cl->get_contextids();
+        $this->assertContains(\context_user::instance($user1->id)->id, $contexts);
+        $this->assertContains(\context_user::instance($user2->id)->id, $contexts);
+    }
 }