question about xml:base value generated by xi:include

[Marco Randazzo <Marco.Randazzo@iit.it>]

Dear all,
I have a question about the value of attribute xml:base generated when processing an xi:include. Let me explain it with an example.

My example employs xi:include elements to include other xml files. It is constituted by a main.xml file which includes another file (include1.xml) stored in a subfolder, called include1.

include1.xml, in turn, includes another xml file (include2.xml) stored in a subfolder of include1 which is called include2.

Overall, the example consists of four folder levels and only the last file, include4.xml, contains data.

This is the contents of the files:

 

./main.xml

<?xml version="1.0" encoding="UTF-8" ?>

<main  xmlns:xi="http://www.w3.org/2001/XInclude">

    <xi:include href="" />

</main >

 

/include1/include1.xml

<?xml version="1.0" encoding="UTF-8" ?>

<level1  xmlns:xi="http://www.w3.org/2001/XInclude">

               <xi:include href="" />

</level1 >

 

./include1/include2/include2.xml

<?xml version="1.0" encoding="UTF-8" ?>

<level2  xmlns:xi="http://www.w3.org/2001/XInclude">

               <xi:include href="" />

</level2 >

 

./include1/include2/include3/include3.xml

<?xml version="1.0" encoding="UTF-8" ?>

<level3  xmlns:xi="http://www.w3.org/2001/XInclude">

               <xi:include href="" />

</level3 >

 

./include1/include2/include3/include4/include4.xml

<?xml version="1.0" encoding="UTF-8" ?>

<level4  xmlns:xi="http://www.w3.org/2001/XInclude">

    <data> 0 </data>

    <data> 1 </data>

</level4 >

 

When I process main.xml, I obtain the following result:

 

<main xmlns:xi="http://www.w3.org/2001/XInclude">

  <level1 xml:base="./include1/include1.xml">

    <level2 xml:base="./include1/include2/include2.xml">

      <level3 xml:base="./include2/include3/include3.xml">

        <level4 xml:base="./include3/include4/include4.xml">

          <data>0</data>

          <data>1</data>

        </level4>

      </level3>

    </level2>

  </level1>

</main>

 

The xml tree is correct, but I have doubts about the value of the attribute xml:base.

In particular:

- level1: I think that the value of xml:base  ( i.e. ./include1/include1.xml) is correct.

- level2: xml:base  value is correct if its meaning is a path relative to the root file. Otherwise, if xml:base is supposed to store a path relative to the current file, then it should be  ./include2/include2.xml.

- level3: This seems to be not correct, neither as an absolute path, nor as a relative path. I think it should be  ./include1/include2/include3/include3.xml as a path relative to the root file or ./include3/include3.xml as a path relative to the current file.

- level4: Same as level3.

 

I also tried to execute a Xquery command http://www.xqueryfunctions.com/xq/fn_base-uri.html on the output.

The result returned by base-uri(//level3) is:

file:///C:/software/test_include/include1/include1/include2/include2/include3/include3.xml

which I think is wrong, I think it should be:

file:///C:/software/test_include/include1/include2/include3/include3.xml

 

I thus suspect that either the implementation of how xi:include generates the value of xml:base or the implementation of base-uri function has a problem.

My suspect is on xi:include. What do you think?
I currently experienced the same strange behavior on two different XML/XQuery processors, i.e.
- baseX http://basex.org (wrapping SAX xml library)
- Saxon EE 9.7 https://www.saxonica.com/download/java.xml