1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/FunctionContext.java,v 1.6 2005/02/09 14:30:00 elharo Exp $ 3 * $Revision: 1.6 $ 4 * $Date: 2005/02/09 14:30:00 $ 5 * 6 * ==================================================================== 7 * 8 * Copyright (C) 2000-2002 bob mcwhirter & James Strachan. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions, and the following disclaimer. 17 * 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions, and the disclaimer that follows 20 * these conditions in the documentation and/or other materials 21 * provided with the distribution. 22 * 23 * 3. The name "Jaxen" must not be used to endorse or promote products 24 * derived from this software without prior written permission. For 25 * written permission, please contact license@jaxen.org. 26 * 27 * 4. Products derived from this software may not be called "Jaxen", nor 28 * may "Jaxen" appear in their name, without prior written permission 29 * from the Jaxen Project Management (pm@jaxen.org). 30 * 31 * In addition, we request (but do not require) that you include in the 32 * end-user documentation provided with the redistribution and/or in the 33 * software itself an acknowledgement equivalent to the following: 34 * "This product includes software developed by the 35 * Jaxen Project (http://www.jaxen.org/)." 36 * Alternatively, the acknowledgment may be graphical using the logos 37 * available at http://www.jaxen.org/ 38 * 39 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 41 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 42 * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT 43 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 45 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 46 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 47 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 48 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 49 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * ==================================================================== 53 * This software consists of voluntary contributions made by many 54 * individuals on behalf of the Jaxen Project and was originally 55 * created by bob mcwhirter <bob@werken.com> and 56 * James Strachan <jstrachan@apache.org>. For more information on the 57 * Jaxen Project, please see <http://www.jaxen.org/>. 58 * 59 * $Id: FunctionContext.java,v 1.6 2005/02/09 14:30:00 elharo Exp $ 60 */ 61 62 63 package org.jaxen; 64 65 /*** Implemented by classes that know how to resolve xpath function names and 66 * namespaces to implementations of these functions. 67 * 68 * <p> 69 * By using a custom <code>FunctionContext</code>, new or different 70 * functions may be installed and available to XPath expression writers. 71 * </p> 72 * 73 * @see XPathFunctionContext 74 * 75 * @author <a href="mailto:bob@werken.com">bob mcwhirter</a> 76 */ 77 public interface FunctionContext 78 { 79 /*** An implementation should return a <code>Function</code> implementation object 80 * based on the namespace URI and local name of the function-call 81 * expression. 82 * 83 * <p> 84 * It must not use the prefix parameter to select an implementation, 85 * because a prefix could be bound to any namespace; the prefix parameter 86 * could be used in debugging output or other generated information. 87 * The prefix may otherwise be completely ignored. 88 * </p> 89 * 90 * @param namespaceURI the namespace URI to which the prefix parameter 91 * is bound in the XPath expression. If the function 92 * call expression had no prefix, the namespace URI 93 * is <code>null</code>. 94 * @param prefix the prefix that was used in the function call 95 * expression 96 * @param localName the local name of the function-call expression. 97 * If there is no prefix, then this is the whole 98 * name of the function. 99 * 100 * @return a Function implementation object. 101 * @throws UnresolvableException when the function cannot be resolved. 102 */ 103 Function getFunction( String namespaceURI, 104 String prefix, 105 String localName ) throws UnresolvableException; 106 }