Le 26/03/2021 09:58, Steven Pemberton <steven.pemberton@cwi.nl> a écrit :

Ah right. It's a shame really (from a user-consistency point of view) that it is different from how instance() works.

In fact 

event('response-headers')[name = 'last-modified']/value

isn't working for me, which I will further investigate, but

event('response-headers')//[name = 'last-modified']/value

is.

Thanks.

Steven

On Thursday 25 March 2021 18:22:09 (+01:00), Erik Bruchez wrote:

The spec says that event('response-headers') returns a `node-sequence`. So you have, in an informal way, using parentheses and commas to denote the sequence, something like this:

    (
        <header>
            <name>last-modified</name>
            <value>Wed, 24 Mar 2021 02:26:50 GMT</value>
        </header>
    ,
        <header>
            <name>content-type</name>
            <value>application/xml</value>
        </header>

    ,

    etc.
    )

A sequence is similar to an array (although in XPath 3 arrays are something else yet!). So you could write:

    event('response-headers')[2]

and this would, in the above case, return the `content-type` header element.

But you cannot write:

    event('response-headers')/header

because each item in the sequence doesn't have a `header` child element. It has `name` and `value` children elements only.

The following might not work with all implementations, and arguably shouldn't:

    event('response-headers')/../header

because it is assuming that all the elements in the sequence have a parent node and that it is the same parent node for all `header` elements. This is not required by the spec. The `header` elements can all be parent-less.

Similarly, you cannot reliably write:

    event('response-headers')[1]/following-sibling::header

because the elements are not required to be siblings (and probably should not be). 

To conclude, this is the correct and simple way to write your expression:

    event('response-headers')[name = 'last-modified']/value

:)

-Erik

On Mon, Mar 22, 2021 at 3:40 AM Steven Pemberton <steven.pemberton@cwi.nl> wrote:

Ok, so
        <setvalue ref="lm"
value="event('response-headers')/../header[name='last-modified']/value"/>

works as well. Not sure why the .. step is needed.

Steven

On Sunday 21 March 2021 21:04:46 (+01:00), Steven Pemberton wrote:

 > In a submit-done handler, is this really the best way to get to the
"last-modified' header?
 >
 > <setvalue ref="lm"
value="event('response-headers')/name[.='last-modified']/following-sibling::value"/>

>
 >
 > I was rather disappointed that this didn't work:
 >
 > <setvalue ref="lm"
value="event('response-headers')/header[name='last-modified']/value"/>
 >
 > Steven
 >
--