Designer scripting uses an event-based model that allows
you to alter various aspects of objects on a form at run time. As
a form designer, you add scripts to objects based on when you want
the script to execute. For example, you might place the following
script on the click event of a button object so
that at run time, when a user clicks the button, a message box appears
with a message:
xfa.host.messageBox("This is a message for a form filler.", "User Feedback", 3);
Scripts associated with a particular event execute whenever that
event occurs. Some events can occur multiple times within the same
form filling session. For example, the following script adds one
to the current value of a numeric field:
NumericField1.rawValue = NumericField1.rawValue + 1;
If you add this script to the calculate event
for NumericField1, when you open the form for the
first time, NumericField1 displays the value 2.
This indicates that the calculate event occurred
twice in the sequence of events that occurred when the form was
opened.
