PHP debugbar - Quick Start
<?php
use DebugBar\StandardDebugBar;
$debugbar = new StandardDebugBar();
$debugbarRenderer = $debugbar->getJavascriptRenderer();
$debugbar["messages"]->addMessage("hello world!");
?>
<html>
<head>
<?php echo $debugbarRenderer->renderHead() ?>
</head>
<body>
...
<?php echo $debugbarRenderer->render() ?>
</body>
</html>