| /* |
| * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.xml.xpath; |
| |
| import javax.xml.namespace.QName; |
| |
| /** |
| * <p><code>XPathFunctionResolver</code> provides access to the set of user defined <code>XPathFunction</code>s.</p> |
| * |
| * <p>XPath functions are resolved by name and arity. |
| * The resolver is not needed for XPath built-in functions and the resolver |
| * <strong><em>cannot</em></strong> be used to override those functions.</p> |
| * |
| * <p>In particular, the resolver is only called for functions in an another |
| * namespace (functions with an explicit prefix). This means that you cannot |
| * use the <code>XPathFunctionResolver</code> to implement specifications |
| * like <a href="http://www.w3.org/TR/xmldsig-core/">XML-Signature Syntax |
| * and Processing</a> which extend the function library of XPath 1.0 in the |
| * same namespace. This is a consequence of the design of the resolver.</p> |
| * |
| * <p>If you wish to implement additional built-in functions, you will have to |
| * extend the underlying implementation directly.</p> |
| * |
| * @author <a href="mailto:Norman.Walsh@Sun.com">Norman Walsh</a> |
| * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a> |
| * @see <a href="http://www.w3.org/TR/xpath#corelib">XML Path Language (XPath) Version 1.0, Core Function Library</a> |
| * @since 1.5 |
| */ |
| public interface XPathFunctionResolver { |
| /** |
| * <p>Find a function in the set of available functions.</p> |
| * |
| * <p>If <code>functionName</code> or <code>arity</code> is <code>null</code>, then a <code>NullPointerException</code> is thrown.</p> |
| * |
| * @param functionName The function name. |
| * @param arity The number of arguments that the returned function must accept. |
| * |
| * @return The function or <code>null</code> if no function named <code>functionName</code> with <code>arity</code> arguments exists. |
| * |
| * @throws NullPointerException If <code>functionName</code> or <code>arity</code> is <code>null</code>. |
| */ |
| public XPathFunction resolveFunction(QName functionName, int arity); |
| } |