Add user dependent availability to actions for interactive steps

classes/local/table/interaction_attention_table.php

@@ -109,12 +109,24 @@ public function init() {
      * @throws \invalid_parameter_exception
      */
     public function col_tools($row) {
+        global $USER;
         $output = '';
         $step = step_manager::get_step_instance($row->stepinstanceid);
 
         $tools = interaction_manager::get_action_tools($step->subpluginname, $row->processid);
+        $toolsstrings = array_map(fn($action) => $action['action'], $tools);
+
+        $availabletoolsstrings = lib_manager::get_step_interactionlib($step->subpluginname)->
+            get_available_actions_for_user($toolsstrings, $USER->id, $row->courseid);
+
         foreach ($tools as $tool) {
-            $output .= $this->format_icon_link($tool['action'], $row->processid, $step->id, $tool['alt']);
+            // Only show actions which are valid actions and which are available to the current user.
+            if (in_array($tool['action'], $toolsstrings) && in_array($tool['action'], $availabletoolsstrings)) {
+                $output .= $this->format_icon_link($tool['action'], $row->processid, $step->id, $tool['alt']);
+            }
+        }
+        if (empty($output)) {
+            $output = get_string('noactionsavailable', 'tool_lifecycle');
         }
         return $output;
     }

lang/de/tool_lifecycle.php

@@ -162,6 +162,7 @@
 
 $string['coursename'] = 'Kursname';
 $string['lastaction'] = 'Letzte Aktion am';
+$string['noactionsavailable'] = 'Sie können keine Aktion ausführen. Warten Sie, bis ein anderer User dies tut.';
 
 $string['workflow_started'] = 'Workflow gestartet.';
 $string['workflow_is_running'] = 'Workflow läuft.';

lang/en/tool_lifecycle.php

@@ -167,6 +167,7 @@
 
 $string['coursename'] = 'Course name';
 $string['lastaction'] = 'Last action on';
+$string['noactionsavailable'] = 'You cannot execute any action but have to wait for another user to handle this course.';
 $string['anonymous_user'] = 'Anonymous User';
 
 $string['workflow_started'] = 'Workflow started.';

step/interactionlib.php

@@ -105,4 +105,23 @@ abstract public function handle_interaction($process, $step, $action = 'default'
     public function get_due_date($processid, $stepid) {
         return null;
     }
+
+    /**
+     * Method to limit the actions to specific users. Returns all actions by default so if not overwritten all actions are available
+     * to any user. You can overwrite this method to filter the $actionstrings array according to your needs to limit the actions
+     * shown to the given user.
+     *
+     * Care: When overwriting this method you want to make sure that at least one user can use at least one action or have a timeout
+     * in your step to avoid any deadlocked workflows.
+     *
+     * @param array $actionstrings array of action strings. These should match the strings with the key 'action'
+     *  in {@see get_action_tools} return array.
+     * @param int $userid the id of the user for whom the returned actions should be visible
+     * @param int $courseid the id of the currently handled course
+     * @return array the (possibly) filtered $actions array containing the strings of the actions which should be available to the
+     *  given user
+     */
+    public function get_available_actions_for_user(array $actionstrings, int $userid, int $courseid) : array {
+        return $actionstrings;
+    }
 }