How to call Javascript function in PHP?

WordPress Theme Development: How can I trigger a JavaScript function when a particular widget's save button is pressed in widgets.php in the admin area?

• This almost works but the alert won't fire on the first click on the Save button. It does after the second click however. So I'm looking for a way that is more reliable. class My_Widget extends WP_Widget { function __construct() { parent::__construct( 'my_widget', 'My Widget', array( 'description' => __( 'This is my widget.', 'my-widget' ), ) ); } function form( $instance ) { $input_id = "test_my_widget_" . uniqid(); ?> <input type="hidden" id="test_my_widget" value="" /> <script type="text/javascript"> jQuery( "#<?php echo $input_id; ?>" ).closest( "form" ).find( 'input[type=submit]' ).click( function( event ) { alert( 'clicked' ); }); </script> <?php } }

• Answer:

  Try .on("click", "a.foo", fn); vs. .click() which looks in the live DOM (widgets are added by Javascript and thus are not always in the original DOM present when the page loads). http://api.jquery.com/on/