What should not be used in a view ?

[eluser]toopay[/eluser]
Related with MVC approach, the view should be the final output. Thats means, avoid any databasing or core process, is a good practice (or even neccesary). This have one purpose, to make your app manageable by clear separated logic : Model for database modelling, COntroller for I/O processing and View generally just for templating stuff.

Thats the guideline, for me. So, as long as you didnt feel that your app is out of your control, or hard to manage, then you're fine.