Modal Size

Refer to Bootstrap modal optional sizes, Modals have two optional sizes.

how can implement these two sizes?

in Modal widget it’s hard coded:

echo Html::beginTag('div', ['class' => 'modal-dialog']) . "\n"

These sizes were introduced in version 3.1, I’m pretty sure Yii still uses version 3.0.

Yup… a case for enhancement request on github since this is a new bootstrap 3.1 feature.