package net.sf.saxon.functions;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.*;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.AtomicValue;
import net.sf.saxon.value.QNameValue;
import net.sf.saxon.type.BuiltInAtomicType;


/**
* This class supports the resolve-QName function in XPath 2.0
*/

public class ResolveQName extends SystemFunction {

    /**
    * Evaluate the expression
    */

    public Item evaluateItem(XPathContext context) throws XPathException {
        AtomicValue arg0 = (AtomicValue)argument[0].evaluateItem(context);
        if (arg0 == null) {
            return null;
        }

        CharSequence lexicalQName = arg0.getStringValueCS();
        final NameChecker checker = context.getConfiguration().getNameChecker();

        NodeInfo element = (NodeInfo)argument[1].evaluateItem(context);
        NamespaceResolver resolver = new InscopeNamespaceResolver(element);
        StructuredQName qName;

        try {
            qName= StructuredQName.fromLexicalQName(lexicalQName, true, checker, resolver);
        } catch (XPathException e) {
            e.maybeSetLocation(this);
            throw e;
        }

        return new QNameValue(qName, BuiltInAtomicType.QNAME);
    }

}

//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//
