Re: [Xsltforms-support] solved (was: Re: select1, itemset, value (what is this form doing wrong?))

[Steven P. <ste...@cw...>]

On Tue, 18 Jul 2017 10:58:58 +0200, C. M. Sperberg-McQueen  
<cm...@bl...> wrote:

> The problem here is so simple it’s slightly embarrassing:  the ‘ref’
> attribute on xf:select sets the context item, so the relative expression
> in the xf:itemset/@nodeset attribute cannot (as written) succeed:  no
> attribute every has element children.  If one makes it absolute
> (lead with instance(‘name’)/… or with ../../), the drop down menu
> ceases to be empty.

Just as a reminder for everyone, if you have a @ref on a control (which as  
Michael points out resets the context), and you have a nested expression  
that you want to be relative to the same thing the ref was relative to  
before resetting the context, there is a solution: the context() function.

This function gives you the context used for the ref, while "." gives you  
the context produced by the ref.

Example:

     <select ref="p[@id='select']/@items">
       <itemset ref="list/item">

the itemset would try to reference "p[@id='select']/@items/list/item"  
(obviously empty).

     <select ref="p[@id='select']/@items">
       <itemset ref="context()/list/item">

would be evaluated in the same contact as the ref on <select>.

You can see another example of context() being used in this example:
    http://homepages.cwi.nl/~steven/forms/examples/data-driven/

>> - Second, when I try to use xf:output in the xf:label element,
>> I get an error; ditto when I try to use a constant but remove the @ref
>> binding attribute.  Are both the value and the label of an itemset
>> required to use @ref?
>
> For this I have currently found no simple solution.

This may help:

   <repeat ref="*">
      <input ref=".[count(*)=0]"><label><output value="concat(name(.), ':  
')"/></label></input>
      <output value="if(count(*)=0, '', concat(name(.), ': '))"/>
      <repeat ref="@*" class="inline">
        <input ref="."><label><output value="concat('@', name(.),  
'=')"/></label></input>
      </repeat>

     **NEST HERE**

   </repeat>

At the point **NEST HERE** you just copy and paste the whole repeat again;  
do this as many times as needed to match the maximum depth of elements in  
the instance you have.

In your case you need outputs not inputs, so just replace all <input>s  
with <output>s.

You can see it working at  
http://homepages.cwi.nl/~steven/forms/examples/data-driven/edit.xml

It takes any random XML instance, and allows you to edit it (up to a  
maximum depth).

Hope this helps.

Steven