Posted by bsteuhl on
URL: https://discuss.orbeon.com/How-to-add-a-conditional-attribute-for-a-sum-tp32243p1478547.html

Never mind I figured it out - set an xforms:output using value attribute with a conditional test to see if the sum is 'castable as xs:integer'.  If it is castable, perform calculation, string appears as error on xform.  Thanks.