to validate multibox in a jsp with struts

[pavani potnuru]

Hi,
I am using multibox in a jsp page. I have to validate such a way that if any user does not click any box, it should display an error message saying that atleast one checkbox have to be selected.I am working on struts, so i would like to know if there are any autovalidation or in any other way....
Thanks in advance
pav

[Merrill Higginson]

If you're defining this property in a DynaActionForm, specify initial="{}" when you define it in the struts-config.xml file. If you're writing your own ActionForm, overrride the reset(...) method and specify

myProperty = new String[0];

somewhere in that method. Once you've done this, you can simply use the standard "required" validation for this property.

The reason you need to initialize it as an empty String array is that if no checkbox is checked, nothing will get set to the server, and the validation framework doesn't recognize it.
[ November 25, 2007: Message edited by: Merrill Higginson ]