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