Method filter

/**
 * Method to filter a field value.
 *
 * @param   \SimpleXMLElement  $element  The SimpleXMLElement object representing the `<field>` tag for the form field object.
 * @param   mixed              $value    The form field value to validate.
 * @param   string             $group    The field name group control value. This acts as an array container for the field.
 *                                       For example if the field has name="foo" and the group value is set to "bar" then the
 *                                       full field name would end up being "bar[foo]".
 * @param   Registry           $input    An optional Registry object with the entire data set to validate against the entire form.
 * @param   Form               $form     The form object for which the field is being tested.
 *
 * @return  mixed   The filtered value.
 *
 * @since   4.0.0
 */
public function filter(\SimpleXMLElement $element, $value, $group = null, Registry $input = null, Form $form = null)
{
    $return = array();
    foreach ((array) $value as $action => $ids) {
        // Build the rules array.
        $return[$action] = array();
        foreach ($ids as $id => $p) {
            if ($p !== '') {
                $return[$action][$id] = $p == '1' || $p === 'true';
            }
        }
    }
    return $return;
}