Primefaces offers several ways to do client side stuff from the server. For examples see here: http://www.primefaces.org/showcase/ui/misc/requestContext.xhtml
While I use primefaces I prefer to keep my hands out of the cookie jar with stuff like this. I mean a datepicker can be replaced with a js widget in 20 minutes if you use a composite component that wraps primefaces date picker. However this stuff would be painful to replace. So my question is, could this be done in some way with JSF or myfaces-impl? cheers