How do u preffer ur Javascript in PHP?

Is it better if u have ur javascript alone (for example a good JS framework to make anykind of UI elements u need?) or would u preffer having a good set of PHP classes that generates those UI elements for u from PHP w/o even touching JS or even knowing it? to be clear, Would u write this <script type="text/javascript>alert("I preffer pure JS");</script> or would u write JS::Alert("I preffer using PHP code"); Which one would u prefer? or which method do u use?