[erlang-questions] xmerl scan file and validate using schema

[Frans Schneider]

Dear list,

I would like to use validation while reading XML files using 
xmerl_scan:file/2 or even better, using xmerl_xsd:validate/2 with a 
previously processed schema. In both cases, I get the error 
{fetch_fun_failed,{http,"http://www.w3.org/2001/xml.xsd"}}. However, the 
documentation gives no details on what the fetch function should look 
like and looking through the sources did not help much. I also made a 
local copy of the imported xml.xsd file and tried several options 
without luck.

My question is if somebody knows about an easy way to get this working? 
The xsd's head is listed below.

NB: I know about Erlsom, which does work well but lacks line numbers in 
the output which I need for reporting errors in the XML file.

Thanks,

Frans

<?xml version="1.0" encoding="UTF-8"?>
<!-- Copyright OASIS Open 2010. All Rights Reserved. -->
<xs:schema xmlns:xacml="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17"
	xmlns:xs="http://www.w3.org/2001/XMLSchema"
	targetNamespace="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17"
	elementFormDefault="qualified" attributeFormDefault="unqualified">

	<xs:import namespace="http://www.w3.org/XML/1998/namespace"
		schemaLocation="http://www.w3.org/2001/xml.xsd"/>