MultiSelect: add table extension trait

library/Director/Web/Table/Extension/MultiSelect.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Icinga\Module\Director\Web\Table\Extension;
+
+use ipl\Web\Url;
+
+// Could also be a static method, MultiSelect::enable($table)
+trait MultiSelect
+{
+    protected function enableMultiSelect($url, $sourceUrl, array $keys)
+    {
+        $this->addAttributes([
+            'class' => 'multiselect'
+        ]);
+
+        $prefix = 'data-icinga-multiselect';
+        $multi = [
+            "$prefix-url"         => Url::fromPath($url),
+            "$prefix-controllers" => Url::fromPath($sourceUrl),
+            "$prefix-data"        => implode(',', $keys),
+        ];
+
+        $this->addAttributes($multi);
+
+        return $this;
+    }
+}