Form Fitlers or Behaviour in a Datalist

[acurs]

Hi,
I have defined a custom datalist where I have some fields that I want to get calculated from the others.
i.e. I have a duration (in days - int value) field that's get calculated with the startdate and duedate fields.

In order to do that I tried to use a form filter like they mention in this post, it is pretty much the same I am needing
http://www.boulderhopkins.com/2010/10/creating-calculated-datalist-columns-in.html

The datalist have many properties (36 properties), many are going to be updated directly through the datalist page and for the others I am trying to figure out how to update some values from a custom workflow.

What would you recommend me, a form filter or a behaviour approach in order to get automatic updates on certain fields?
I am using Share as the repository client, there been some changes in the JAVA Api of the AbstractFilter class, I am using 3.4d

Thanks

[matjazmuhic]

Use the form filters. Then you don't even need to specify those calculated field in your content model. You can just dynamically add them on to the form with in your form filter.

[acurs]

thanks, I will try to make the fields definitions for adding it dinamically to the form…