Feedback on 1.1: instance src attribute broken

The src attribute is all but gone from XForms, having been delegated to 
the host language to provide.

The one place it still appears is on the instance element.  Here I am 
going to argue that the semantic of src inherited from HTML is also broken 
for instance, so we either need to change it or rename the attribute so we 
can change the semantics.

The problematic behavior is that the content of the instance is 
*overridden* by content obtained from a URI given by src.  The behavior 
should be that the src URI is used to obtain *default* content for the 
instance if it is empty.

This is important to document-centric applications of XForms, which must 
solve the save/reload problem.  These applications are unable to use the 
src attribute to initialize an XForm because if the user then fills out 
some data, saves the document containing the XForm, then reloads the 
document, the src attribute is exercised and a new blank copy of the 
instance is obtained, wiping out the user input obtained before the save 
operation.

Currently, we solve this problem by 1) recommending people not use src, 
and 2) once the src is exercised, we destroy the attribute when we put the 
XML it obtains into the document.  But this is really not the ideal 
because the src is part of the form "application".  User input is 
technically only supposed to affect the *content* of instance elements and 
not any other part of the "application".

In conclusion, it might be best just to allow src to wholly go over to 
XHTML, and then include a new 'resource' attribute that behaves 
differently.

John M. Boyer, Ph.D.
Senior Product Architect/Research Scientist
Co-Chair, W3C XForms Working Group
Workplace, Portal and Collaboration Software
IBM Victoria Software Lab
E-Mail: boyerj@ca.ibm.com  http://www.ibm.com/software/

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