package net.sf.saxon.functions;
import net.sf.saxon.expr.Expression;
import net.sf.saxon.expr.ExpressionVisitor;
import net.sf.saxon.expr.StaticProperty;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.om.StandardNames;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.AtomicType;
import net.sf.saxon.type.ItemType;
import net.sf.saxon.value.BooleanValue;
public class Lang extends SystemFunction {
/**
* preEvaluate: this method suppresses compile-time evaluation by doing nothing
* @param visitor an expression visitor
*/
public Expression preEvaluate(ExpressionVisitor visitor) {
return this;
}
public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
if (argument.length==1) {
if (contextItemType == null) {
XPathException err = new XPathException("The context item for lang() is undefined");
err.setErrorCode("XPDY0002");
err.setIsTypeError(true);
err.setLocator(this);
throw err;
} else if (contextItemType instanceof AtomicType) {
XPathException err = new XPathException("The context item for lang() is not a node");
err.setErrorCode("XPTY0004");
err.setIsTypeError(true);
err.setLocator(this);
throw err;
}
}
return super.typeCheck(visitor, contextItemType);
}
/**
* Evaluate in a general context
*/
public Item evaluateItem(XPathContext c) throws XPathException {
NodeInfo target;
if (argument.length > 1) {
target = (NodeInfo)argument[1].evaluateItem(c);
} else {
Item current = c.getContextItem();
if (current==null) {
XPathException err = new XPathException("The context item is undefined");
err.setErrorCode("XPDY0002");
err.setXPathContext(c);
throw err;
}
if (!(current instanceof NodeInfo)) {
XPathException err = new XPathException("The context item is not a node");
err.setErrorCode("XPTY0004");
err.setXPathContext(c);
throw err;
}
target = (NodeInfo)current;
}
final Item arg0Val = argument[0].evaluateItem(c);
final String testLang = (arg0Val==null ? "" : arg0Val.getStringValue());
boolean b = isLang(testLang, target);
return BooleanValue.get(b);
}
/**
* Determine the dependencies
*/
public int getIntrinsicDependencies() {
return (argument.length == 1 ? StaticProperty.DEPENDS_ON_CONTEXT_ITEM : 0);
}
/**
* Test whether the context node has the given language attribute
* @param arglang the language being tested
* @param target the target node
*/
public static boolean isLang(String arglang, NodeInfo target) {
String doclang = null;
NodeInfo node = target;
while(node!=null) {
doclang = node.getAttributeValue(StandardNames.XML_LANG);
if (doclang!=null) {
break;
}
node = node.getParent();
if (node==null) {
return false;
}
}
if (doclang==null) {
return false;
}
while (true) {
if (arglang.equalsIgnoreCase(doclang)) {
return true;
}
int hyphen = doclang.indexOf("-");
if (hyphen<0) {
return false;
}
doclang = doclang.substring(0, hyphen);
}
}
}
//
// 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.
//