- From: Christophe Strobbe <christophe.strobbe@esat.kuleuven.be>
- Date: Wed, 25 Jan 2006 18:53:33 +0100
- To: w3c-wai-gl@w3.org
Hi, We still don't have a satisfactory solution for "programmatically determined" and AT. "Theoretically programmatically determined because defined in formal specifications" is not sufficient because there may be features in specifications that no AT has implemented yet. On the other hand we can't just say "AT" without saying which AT. What we have not discussed so far is the distinction between - programmatically determined in a declarative manner, and - programmatically determined in an imperative manner. This distinction is based on the distinction between declarative and imperative (programming) languages: - imperative languages basically describe sequences of operations, - declarative languages basically describe what is computer.[1] We deleted the old SC 3.2 L1 SC1 ("Any change of context is implemented in a manner that can be programmatically determined.") on the basis that any change of context that cannot be programmatically determined will simply never happen because a UA cannot detect that it is supposed to happen. The SC would not have been removed if it had read: "Any change of context is implemented in a declarative way". That would have ruled out changes of context caused by JavaScript (which is an imperative language), which many will find to strong at level 1. The distinction between declarative and imperative is interesting because it is what gave rise to the XML Events spec (http://www.w3.org/TR/2003/REC-xml-events-20031014/) and the use of XML Events in XForms (http://www.w3.org/TR/2003/REC-xforms-20031014/). Many things that HTML form authors do with JavaScript (imperative code) can now be done with XML Events (required fields, hints, context-sensitive help, adding fields based on the value of other fields, etc). This has the advantage that events (and therefore changes of context) are "statically analyzable": there's no need for AUs to actually run any code (JavaScript) to find out what kinds of events might happen. Can this be a way out of this catch-22? [1] More on this subject at http://www.csc.liv.ac.uk/~frans/OldLectures/2CS24/declarative.html and http://en.wikipedia.org/wiki/Declarative_programming. Regards, Christophe Strobbe -- Christophe Strobbe K.U.Leuven - Departement of Electrical Engineering - Research Group on Document Architectures Kasteelpark Arenberg 10 - 3001 Leuven-Heverlee - BELGIUM tel: +32 16 32 85 51 http://www.docarch.be/ Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
Received on Wednesday, 25 January 2006 17:53:43 UTC