Re: function-available gone?

Some delay in the W3C server caused the question email below (also at [1]) 
to appear after my answer [2] in the archive.

[1] http://lists.w3.org/Archives/Public/www-forms/2007Jul/0019.html
[2] http://lists.w3.org/Archives/Public/www-forms/2007Jul/0018.html

John M. Boyer, Ph.D.
STSM: Lotus Forms Architect and Researcher
Chair, W3C Forms Working Group
Workplace, Portal and Collaboration Software
IBM Victoria Software Lab
E-Mail: boyerj@ca.ibm.com 

Blog: http://www.ibm.com/developerworks/blogs/page/JohnBoyer





Elliotte Harold <elharo@metalab.unc.edu> 
Sent by: www-forms-request@w3.org
07/13/2007 03:12 AM

To
John Boyer/CanWest/IBM@IBMCA
cc
www-forms@w3.org
Subject
Re: function-available gone?







John Boyer wrote:

> 1) the form author would have to set up an event handler to run the 
> XPath that called the function-available() function.

No, they just would have needed to use the if function in their XPath.


> 2) The form author would have needed a way to generate a processing halt 

> if the function returned false. 

Or they could have called a different expression instead,


> By comparison, the current method allows the XForms processor to 
> determine very early in the lifecycle of the document (i.e. before 
> running any XPaths) whether or not the necessary functions are 
> available.  It is also a much easier way to make such a statement 
> compared to the function method outlined above.
> 

How does one use the current machinery to take one path if a function is 
available and another if the function is not? Assume I do not want to 
halt procesing just because an extension function is missing.

-- 
Elliotte Rusty Harold  elharo@metalab.unc.edu
Java I/O 2nd Edition Just Published!
http://www.cafeaulait.org/books/javaio2/
http://www.amazon.com/exec/obidos/ISBN=0596527500/ref=nosim/cafeaulaitA/