Add category filter to set question selection

administrator/components/com_testquestions/src/Model/SetModel.php

@@ -44,6 +44,31 @@ class SetModel extends AdminModel
         return Factory::getApplication()->getUserState('com_testquestions.edit.set.data', []) ?: $this->getItem();
     }
 
+    public function getQuestions()
+    {
+        $db = Factory::getContainer()->get('DatabaseDriver');
+
+        return $db->setQuery(
+            $db->getQuery(true)
+                ->select(['q.id', 'q.question', 'q.category_id', 'c.title AS category_title'])
+                ->from($db->quoteName('#__testquestions_questions', 'q'))
+                ->leftJoin($db->quoteName('#__testquestions_categories', 'c') . ' ON c.id = q.category_id')
+                ->order('c.title ASC, q.ordering ASC, q.id ASC')
+        )->loadObjectList();
+    }
+
+    public function getCategories()
+    {
+        $db = Factory::getContainer()->get('DatabaseDriver');
+
+        return $db->setQuery(
+            $db->getQuery(true)
+                ->select(['id', 'title'])
+                ->from($db->quoteName('#__testquestions_categories'))
+                ->order($db->quoteName('title') . ' ASC')
+        )->loadObjectList();
+    }
+
     public function save($data)
     {
         $questionIds = array_values(array_unique(array_filter(array_map('intval', (array) ($data['question_ids'] ?? [])))));

administrator/components/com_testquestions/src/View/Set/HtmlView.php

@@ -12,11 +12,15 @@ class HtmlView extends BaseHtmlView
 {
     protected $form;
     protected $item;
+    protected $questions;
+    protected $categories;
 
     public function display($tpl = null)
     {
         $this->form = $this->get('Form');
         $this->item = $this->get('Item');
+        $this->questions = $this->get('Questions');
+        $this->categories = $this->get('Categories');
 
         if (count($errors = $this->get('Errors'))) {
             throw new \RuntimeException(implode("\n", $errors));