package client.net.sf.saxon.ce.functions;
import client.net.sf.saxon.ce.expr.XPathContext;
import client.net.sf.saxon.ce.om.InscopeNamespaceResolver;
import client.net.sf.saxon.ce.om.Item;
import client.net.sf.saxon.ce.om.NamespaceResolver;
import client.net.sf.saxon.ce.om.NodeInfo;
import client.net.sf.saxon.ce.trans.XPathException;
import client.net.sf.saxon.ce.value.AnyURIValue;
import client.net.sf.saxon.ce.value.StringValue;
/**
* This class supports the function namespace-uri-for-prefix()
*/
public class NamespaceForPrefix extends SystemFunction {
public NamespaceForPrefix newInstance() {
return new NamespaceForPrefix();
}
/**
* Evaluate the function
* @param context the XPath dynamic context
* @return the URI corresponding to the prefix supplied in the first argument, or null
* if the prefix is not in scope
* @throws XPathException if a failure occurs evaluating the arguments
*/
public Item evaluateItem(XPathContext context) throws XPathException {
NodeInfo element = (NodeInfo)argument[1].evaluateItem(context);
StringValue p = (StringValue)argument[0].evaluateItem(context);
String prefix;
if (p == null) {
prefix = "";
} else {
prefix = p.getStringValue();
}
NamespaceResolver resolver = new InscopeNamespaceResolver(element);
String uri = resolver.getURIForPrefix(prefix, true);
if (uri == null) {
return null;
}
return new AnyURIValue(uri);
}
}
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is “Incompatible With Secondary Licenses”, as defined by the Mozilla Public License, v. 2.0.