->add('isStarred', 'filter_checkbox')
->add('previewPicture', 'filter_checkbox', array(
'apply_filter' => function (QueryInterface $filterQuery, $field, $values) {
+ $value = $values['value'];
+
+ if (false === $value) {
+ return;
+ }
+
$expression = $filterQuery->getExpr()->isNotNull($field);
return $filterQuery->createCondition($expression);