Callbacks and services

Hello!
 
I've created a service that services documents from a database (I used the
ChartService as a base for my service). 
 
Now, if a user gets hold of the service link, I want to be able to check and
see if the visit object is created, and if the user has access to the record
in the database. If the user isn't logged in, I want to present a login page
and then when the user has logged in, go to the service link originally
asked for.
 
When I want this functionallity for pages I implement a validate() function
in the page class and use the callback functionallity (like in the VLib
project). How can I do the same for my service? 
 
thanks,
 
Niklas

niklas.ekman
citat solutions | phone +46 (0)31 710 72 12
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