| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (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.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.jxpath; |
| |
| /** |
| * Extension function interface. Extension functions are grouped into |
| * {@link Functions Functions} objects, which are installed on |
| * JXPathContexts using the |
| * {@link JXPathContext#setFunctions JXPathContext.setFunctions()} |
| * call. |
| * <p> |
| * The Function interface can be implemented directly. However, |
| * most of the time JXPath's built-in implementations should suffice. |
| * See {@link ClassFunctions ClassFunctions} and |
| * {@link PackageFunctions PackageFunctions}. |
| * |
| * @author Dmitri Plotnikov |
| * @version $Revision$ $Date$ |
| */ |
| public interface Function { |
| |
| /** |
| * Computes the value of the function. Each implementation of Function |
| * is responsible for conversion of supplied parameters to the required |
| * argument types. |
| * |
| * @param context can be used to acquire the context in which the |
| * function is being evaluted. |
| * @param parameters function arguments |
| * @return Object result |
| */ |
| Object invoke(ExpressionContext context, Object[] parameters); |
| } |