| /* LangFunction.java -- |
| Copyright (C) 2004,2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package gnu.xml.xpath; |
| |
| import java.util.List; |
| import javax.xml.namespace.QName; |
| import org.w3c.dom.Element; |
| import org.w3c.dom.Node; |
| |
| /** |
| * The <code>lang</code> function returns true or false depending on whether |
| * the language of the context node as specified by xml:lang attributes is |
| * the same as or is a sublanguage of the language specified by the argument |
| * string. The language of the context node is determined by the value of |
| * the xml:lang attribute on the context node, or, if the context node has |
| * no xml:lang attribute, by the value of the xml:lang attribute on the |
| * nearest ancestor of the context node that has an xml:lang attribute. If |
| * there is no such attribute, then lang returns false. If there is such an |
| * attribute, then lang returns true if the attribute value is equal to the |
| * argument ignoring case, or if there is some suffix starting with - such |
| * that the attribute value is equal to the argument ignoring that suffix of |
| * the attribute value and ignoring case. |
| * |
| * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a> |
| */ |
| final class LangFunction |
| extends Expr |
| { |
| |
| final Expr arg; |
| |
| LangFunction(List args) |
| { |
| this((Expr) args.get(0)); |
| } |
| |
| LangFunction(Expr arg) |
| { |
| this.arg = arg; |
| } |
| |
| public Object evaluate(Node context, int pos, int len) |
| { |
| Object val = arg.evaluate(context, pos, len); |
| String lang = _string(context, val); |
| String clang = getLang(context); |
| while (clang == null && context != null) |
| { |
| context = context.getParentNode(); |
| clang = getLang(context); |
| } |
| boolean ret = (clang == null) ? false : |
| clang.toLowerCase().startsWith(lang.toLowerCase()); |
| return ret ? Boolean.TRUE : Boolean.FALSE; |
| } |
| |
| String getLang(Node node) |
| { |
| while (node != null) |
| { |
| if (node.getNodeType() == Node.ELEMENT_NODE) |
| { |
| String lang = ((Element) node).getAttribute("xml:lang"); |
| if (lang != null) |
| return lang; |
| } |
| node = node.getParentNode(); |
| } |
| return null; |
| } |
| |
| public Expr clone(Object context) |
| { |
| return new IdFunction(arg.clone(context)); |
| } |
| |
| public boolean references(QName var) |
| { |
| return arg.references(var); |
| } |
| |
| public String toString() |
| { |
| return "lang(" + arg + ")"; |
| } |
| |
| } |