Thank you for this extension!
We like to use the preload parameter to include a template with new pages. I looked at the other extensions and found them to be overkill. So I added a fourth parameter to take a template page to your extension form field. Here is the added code (using version 0.1):
CreatePage.php
if ( array_key_exists( 3, $args ) ) {
$html .= Html::hidden( 'preload', trim( $frame->expand( $args[3] ) ) );
}
SpecialCreatePage.php
$preload = '';
if ( $req->getCheck( 'preload' ) ) {
$preload = $req->getText('preload');
}
$target = Title::newFromText( implode( ':', $parts ) )->getLocalUrl( array(
'action' => 'edit',
'redlink' => '1',
'preload' => $preload
) );