Error cause identification for meaningful error messages

A suggestion for future versions of XForms: allowing the
cause of an instance being invalid to be identified so that
more meaningful error messages can be displayed.

Curently, one only knows whether the instance is valid or
invalid.  There seems to be no way to identify what model
item property was violated to case it to become
invalid. This makes it very difficult to create usable forms
which display useful error messages to help the user fix the
problem.

For example, an element might be a required integer that has
a constraint that it must be greater than 42.  Depending on
what the user has entered, different error messages can be
shown: "this field is required, please enter a value,"
"incorrect format for a number," "the number you have
entered is not greater then 42."  Currently, the best you
can do is to have a single error message: "this field is
missing a number greater than 42."

Hoylen
-- 
______________________________________________ Dr Hoylen Sue
h.sue@dstc.edu.au                    http://www.dstc.edu.au/
DSTC Pty Ltd                                 +61 7 3365 4310

Received on Monday, 7 June 2004 02:49:53 UTC