add_filter( ‘hf_form_html’, function( $html ) {
$doc = new DOMDocument( ‘1.0’, ‘UTF-8’ );
$doc->loadHTML( $html );
$attr = array();
$form = $doc->getElementsByTagName( ‘form’ )->item(0);
foreach( $form->attributes as $attribName => $attribNodeVal ) {
$attr[$attribName] = utf8_decode( $form->getAttribute( $attribName ) );
}
if( $attr[‘data-slug’] == ‘my-form-slug’ ) {
…
}
}