roles filter refactor

if the block is in a course, it will consider users with any
of the selected roles assigned in the course or in any sub contexts.

if the block is in a category, it will consider users with any
of the selected roles assigned in the category or in any sub contexts.

if the block is in the dashboard, it will consider users with any
of the selected roles assigned in any context.

if the block is in the system context, it will consider users with any
of the selected roles assigned in any context.

Author: danielneis

classes/audience.php

@@ -123,20 +123,35 @@ public static function meets_cohorts_requirements($notificationid, $userid) {
 
     public static function meets_roles_requirements($notificationid, $userid, $blockid) {
         global $DB;
-        if (!$roles = $DB->get_records('block_advnotifications_roles', ['notificationid' => $notificationid])) {
+        if (!$roles = $DB->get_records('block_advnotifications_roles', ['notificationid' => $notificationid], '', 'roleid')) {
             return true; // There is no role restriction.
         }
-        if ($blockid) {
+        $roles = array_keys($roles);
+
+        if ($blockid > 0) {
             $context = \context_block::instance($blockid);
+            if ($coursecontext = $context->get_course_context(false)) {
+                $context = $coursecontext;
+            } else {
+                $context = $context->get_parent_context(); // It may be category or user context.
+                if ($context instanceof \context_user) {
+                    $context = \context_system::instance();
+                }
+            }
         } else {
             $context = \context_system::instance();
         }
-        foreach ($roles as $r) {
-            if (!user_has_role_assignment($userid, $r->roleid, $context->id)) {
-                return false;
-            }
-        }
-        return true;
+        list($rolessql, $params) = $DB->get_in_or_equal($roles, SQL_PARAMS_NAMED, 'roleid');
+        $sql =
+            'SELECT 1
+               FROM {role_assignments} ra
+               JOIN {context} ctx
+                 ON ctx.id = ra.contextid
+              WHERE ' . $DB->sql_like('ctx.path', ':ctxpath', false) . '
+                AND roleid ' . $rolessql;
+        $params['ctxpath'] = $context->path . '%';
+
+        return $DB->record_exists_sql($sql, $params);
     }
 
     public static function get_users_for_notification($notification) {
@@ -146,11 +161,15 @@ public static function get_users_for_notification($notification) {
         $wheres = [];
         $params = [];
 
-        if (!empty($notification->blockid) && $notification->blockid > 0) {
-            $bcontext = \context_block::instance($notification->blockid);
-            $coursecontext = $bcontext->get_course_context(false);
+        if ($notification->blockid > 0) {
+            $context = \context_block::instance($notification->blockid);
+            if ($coursecontext = $context->get_course_context(false)) {
+                $context = $coursecontext;
+            } else {
+                $context = $context->get_parent_context(); // It may be category context.
+            }
         } else {
-            $coursecontext = \context_system::instance();
+            $context = \context_system::instance();
         }
 
         if ($DB->record_exists('block_advnotifications_coh', ['notificationid' => $notification->id])) {
@@ -165,16 +184,17 @@ public static function get_users_for_notification($notification) {
 
         if ($roles = $DB->get_records_menu('block_advnotifications_roles', ['notificationid' => $notification->id], '', 'roleid')) {
 
-            // TODO: role assignments in sub-contexts.
             $roles = array_keys($roles);
-            list($rolesql, $roleparams) = $DB->get_in_or_equal($roles, SQL_PARAMS_NAMED, 'roleid');
+            list($rolessql, $rolesparams) = $DB->get_in_or_equal($roles, SQL_PARAMS_NAMED, 'roleid');
             $joins[] =
              ' JOIN {role_assignments} ra
-                 ON ra.userid = u.id';
-            $wheres[] = ' ra.contextid = :contextid ';
-            $wheres[] = ' ra.roleid ' . $rolesql;
-            $params['contextid'] = $coursecontext->id;
-            $params = array_merge($params, $roleparams);
+                 ON ra.userid = u.id
+               JOIN {context} ctx
+                 ON ctx.id = ra.contextid';
+            $wheres[] = $DB->sql_like('ctx.path', ':ctxpath', false);
+            $wheres[] = ' ra.roleid ' . $rolessql;
+            $params['ctxpath'] = $context->path . '%';
+            $params = array_merge($params, $rolesparams);
         }
 
         if ($fields = $DB->get_records('block_advnotifications_field', ['notificationid' => $notification->id])) {
@@ -222,14 +242,6 @@ public static function get_users_for_notification($notification) {
             }
         }
 
-        if (isset($coursecontext)) {
-            // TODO: enrolment in sub contexts.
-            $enrolledjoin = get_enrolled_join($coursecontext, 'u.id', true);
-            $joins[] = $enrolledjoin->joins;
-            $wheres[] = $enrolledjoin->wheres;
-            $params = array_merge($params, $enrolledjoin->params);
-        }
-
         $sql = "SELECT u.id
                   FROM {user} u
                    " . implode("\n", $joins) . "