[Exist-open] fn:collection v. fn:doc and a basic XQuery question

[Robert K. <ro...@ko...>]

Hi,

I don't know if this is eXist specific or general XQuery/XPath 2.0 (I 
would say I have a good deal of experience with XPath 1.0, but not 
XQuery and XPath2). I am using the latest from SVN as of this morning.

The function below works when I use fn:doc, but not fn:collection.

Questions:

1. Why doesn't fn:collection work?
2. Why do I need fn:string to get the value of the attribute for the 
link text? Is there a better way? If I don't use fn:string, the 
attribute is added to the a element as a copy (or doing 
<xsl:attribute../> in XSL 1.0). But the value of the attributes in the 
attribute-value-template(?) works as expected (like XPath1).

Here is the function:

declare function local:get-user-groups() as element()* {
   let $user-groups := xmldb:get-user-groups($user)
   for $user-group in $user-groups
     (:let $project-config := fn:collection(concat($ripple-db-uri, 
"/projects/", $user-group))/project.xml/*:)
     let $project-config := fn:doc(concat($ripple-db-uri, "/projects/", 
$user-group, "/project.xml"))/*
     return
       <li>
         <a
           href="#"
           onclick="submitForm('{$project-config/@id}', 
'{$project-config/@db-ref}')">
           {fn:string($project-config/@label)}
         </a>
       </li>
};

thanks,
-Rob