* extra config from a matching PHP widget (defined in HTMLFormElement.php) when constructed using
* OO.ui.infuse().
*
* Currently only supports passing 'hide-if' data.
*
* @ignore
* extra config from a matching PHP widget (defined in HTMLFormElement.php) when constructed using
* OO.ui.infuse().
*
* Currently only supports passing 'hide-if' data.
*
* @ignore