Re: empty fields in SCXML events.

On Apr 5, 2013, at 8:12 PM, Jim Barnett <Jim.Barnett@genesyslab.com<mailto:Jim.Barnett@genesyslab.com>> wrote:

In C.2.1 we say that any data element that is declared but not assigned a value gets ‘undefined’ as its value, so it’s consistent to do that in _event as well.   I don’t think that we can say that <data> elements can have any initial value that evaluates to Boolean false because numbers are common values.  So it’s probably best to say that anything without a value is undefined.

Undefined as in "ECMAScript undefined" or undefined as in "SCXML draft leaves it undefined"? If the latter, what to do with the tests?
  Stefan


-          Jim

From: David Junger [mailto:tffy@free.fr<http://free.fr>]
Sent: Friday, April 05, 2013 2:03 PM
To: Voice Public List
Subject: Re: empty fields in SCXML events.

Le 5 apr 2013 à 19:38, Jim Barnett a écrit :


So we say that the values of empty event fields is ‘Undefined’?  I don’t care personally, I just want something that ECMAScript programmers will find intuitive and consistent.

They (we) will have no problem with 'undefined'. Honestly, it won't matter since you rarely do if(value===undefined) in real code. Unless you expect "" or similar falsy values and you intend to treat them differently. But "" is not a valid event name, or origin, or type, etc, so there is no reason not to test if(value) and thus ignore the type.
"" is a valid event.data but so is undefined or any other special value that we come up with.

                                    David