Re: [Xsltforms-support] confusion over instance() function

[COUTHURES A. <ala...@ag...>]

Hello Stephen,
> I have a bit of confusion over the instance() function,  in 
> XSLForms it returns the root node of the instance, if this is the 
> specification then that is fine but  it seems a bit counter-intuitive as 
> '/' and '//' have different meanings in XPath.
>   
The XForms 1.1 proposed recommendation says : "this function returns a 
node-set containing just the root element node (also called the document 
element node) of the referenced instance data" (AJAXForms was wrong 
returning the document node (/)...).
> If this is correct behaviour then the example from 
> http://www.w3schools.com/xforms/xforms_functions.asp(as below) is wrong.
>
> ****
> instance(string)
>
> An XForms Model can contain more than one instance. This function 
> returns the root node of the specified instance data
>
> <xforms:instance id="orderform">
> <firstName>John</firstName>
> </xforms:instance>
>
> ref="instance('orderform')/firstName"
>
> This example returns a node-set that consists of the firstName element 
> node from the instance named "orderform"
>
> ****
>
>   
Also in the W3C proposed recommendation :

For instance data corresponding to this XML:

<xforms:instance xmlns="" id="orderform">
  <orderForm>
    <shipTo>
      <firstName>John</firstName>
    </shipTo>
  </orderForm>
</xforms:instance>

The following expression selects the |firstName| node. Note that the 
|instance| function returns an element node, effectively replacing the 
leftmost location step from the path:

ref="instance('orderform')/shipTo/firstName"

> As a matter of general interest, do you know of many people who have 
> used XSLForms in production as yet?
>   
Mark Logic has developed an "Application Builder" application delivered 
with Mark Logic Server 4.1. All around the world, people are downloading 
and testing XSLTForms but, because it's free, I don't know who is using 
it in production.

XForms is yet an emerging technology to be used in the promising XRX 
architecture. EMC has now its own engine named Formula but it seems that 
IBM is not working anymore on Ubiquity XForms project and I would not be 
surprised if this project is abandoned soon... XSLTForms is still the 
most mature of its kind !!

Regards,

-Alain