add own logic

src/GetConfigTrait.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Drupal\advanced_search;
+
+use Drupal\advanced_search\Form\SettingsForm;
+
+/**
+ * Simple trait for accessing this modules configuration.
+ */
+trait GetConfigTrait {
+
+  /**
+   * Get a config setting or returns a default.
+   *
+   * @return string
+   *   The config setting or default value.
+   */
+  protected static function getConfig($config, $default) {
+    $settings = \Drupal::config(SettingsForm::CONFIG_NAME);
+    $value = $settings->get($config);
+    return !empty($value) ? $value : $default;
+  }
+
+}