I have same problem. I am writing an extension function to get a variable(string array type) and add a string value to the end of the array. add2Set(arrVar, 'testStr') I get a List from call function's first argument but it is always empty. When I add an element to list and return, no set occurs in list. <from expression="add2Set(arrVar, 'testStr')"/> Another problem is I can not use query="/part/items[0]" type queries, [] are not accepted and predicate can not be used exception is given by jbpm. If anyone find a way to set a value to array, please mail me also. Asiye AYDIN asiye.aydin(a)gmail.com View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4046173#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...