WidgetWithBehaviorScript: Template for a WordPress widget which enqueues an accompanying behavior script; script only output if widget is rendered.

WidgetWithBehaviorScript.widget.php

<?php

class WidgetWithBehaviorScript extends WP_Widget {
	
	function __construct() {
		parent::__construct(__CLASS__, 'Widget with Accompanying Behavior Script', array(
			'classname' => __CLASS__,
			'description' => "This WordPress widget serves as a pattern for how to enqueue a script only if the widget is actually rendered."
		));
		
		// Enqueue the .js script which accompanies the widget
		wp_enqueue_script(
			__CLASS__,
			trailingslashit(get_template_directory_uri()) . __CLASS__ . ".js",
			array('jquery'), // Whatever you want
			filemtime(trailingslashit(TEMPLATEPATH) . __CLASS__ . '.js'),
			true // Must be true (in_footer)
		);
		
		// Schedule an action to remove the enqueued script; this action is 
		// removed if the widget is actually rendered (if the widget() is called)
		add_action("wp_print_footer_scripts", array(__CLASS__, 'remove_enqueued_script'));
	}
	
	/**
	 * Remove the enqueued script
	 */
	function remove_enqueued_script(){
		wp_deregister_script(__CLASS__);
	}
 
	function widget($args, $instance) {
		// Abort the scheduled removal of the enqueued script because the widget is being rendered
		remove_action("wp_print_footer_scripts", array(__CLASS__, 'remove_enqueued_script'));
		
		extract($args, EXTR_SKIP);
		global $Shopp;
		
		echo $before_widget;
		echo $before_title;
		# ...
		echo $after_title;
		# ...
		echo $after_widget;
	}

	function update($new_instance, $old_instance) {}
	function form($instance){}
}

?>

This isn't needed in 3.3 due to [18446] . Just add wp_enqueue_script( '{handle}', '{src}', array( '{deps}' ), '{ver}', true ) to the widget() function. That's it!

Thanks for the heads up!

No Problem. The guy that was having problems with it forked: https://gist.github.com/1172287
Also, I found WHY it broke and we should have it fixed before 3.3 is released. Still, it would still be better to do it right since this hack isn't needed anymore.