Set value of field based on GET param for anonymous users I ran into a strange problem. All forms are cached for anonymous users even if there is a token present in the url. But I need that token to store a "value" field type on a form. Because the form is stored in cache, it does not verify for that get param and set the value accordingly.

I tried using an "after_build" function but that is also not triggered. 

Is there a way I can use the GET param in my code? Or is there a way I can disable caching only for this form? 

Thanks.
Have a look at this module Cache Exclude, it might help you.

And even have look at this link, it is having more details about your problem.