| /* $Id$ |
| * |
| * Copyright 2002-2004 The Apache Software Foundation. |
| * |
| * Licensed 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.tomcat.util.digester; |
| |
| import org.xml.sax.Attributes; |
| |
| /** |
| * <p>Rule implementation that saves a parameter for use by a surrounding |
| * <code>CallMethodRule<code>.</p> |
| * |
| * <p>This parameter may be: |
| * <ul> |
| * <li>an arbitrary Object defined programatically, assigned when the element pattern associated with the Rule is matched |
| * See {@link #ObjectParamRule(int paramIndex, Object param)} |
| * <li>an arbitrary Object defined programatically, assigned if the element pattern AND specified attribute name are matched |
| * See {@link #ObjectParamRule(int paramIndex, String attributeName, Object param)} |
| * </ul> |
| * </p> |
| * |
| * @since 1.4 |
| */ |
| |
| public class ObjectParamRule extends Rule { |
| // ----------------------------------------------------------- Constructors |
| /** |
| * Construct a "call parameter" rule that will save the given Object as |
| * the parameter value. |
| * |
| * @param paramIndex The zero-relative parameter number |
| * @param param the parameter to pass along |
| */ |
| public ObjectParamRule(int paramIndex, Object param) { |
| this(paramIndex, null, param); |
| } |
| |
| |
| /** |
| * Construct a "call parameter" rule that will save the given Object as |
| * the parameter value, provided that the specified attribute exists. |
| * |
| * @param paramIndex The zero-relative parameter number |
| * @param attributeName The name of the attribute to match |
| * @param param the parameter to pass along |
| */ |
| public ObjectParamRule(int paramIndex, String attributeName, Object param) { |
| this.paramIndex = paramIndex; |
| this.attributeName = attributeName; |
| this.param = param; |
| } |
| |
| |
| // ----------------------------------------------------- Instance Variables |
| |
| /** |
| * The attribute which we are attempting to match |
| */ |
| protected String attributeName = null; |
| |
| /** |
| * The zero-relative index of the parameter we are saving. |
| */ |
| protected int paramIndex = 0; |
| |
| /** |
| * The parameter we wish to pass to the method call |
| */ |
| protected Object param = null; |
| |
| |
| // --------------------------------------------------------- Public Methods |
| |
| /** |
| * Process the start of this element. |
| * |
| * @param attributes The attribute list for this element |
| */ |
| public void begin(String namespace, String name, |
| Attributes attributes) throws Exception { |
| Object anAttribute = null; |
| Object parameters[] = (Object[]) digester.peekParams(); |
| |
| if (attributeName != null) { |
| anAttribute = attributes.getValue(attributeName); |
| if(anAttribute != null) { |
| parameters[paramIndex] = param; |
| } |
| // note -- if attributeName != null and anAttribute == null, this rule |
| // will pass null as its parameter! |
| }else{ |
| parameters[paramIndex] = param; |
| } |
| } |
| |
| /** |
| * Render a printable version of this Rule. |
| */ |
| public String toString() { |
| StringBuffer sb = new StringBuffer("ObjectParamRule["); |
| sb.append("paramIndex="); |
| sb.append(paramIndex); |
| sb.append(", attributeName="); |
| sb.append(attributeName); |
| sb.append(", param="); |
| sb.append(param); |
| sb.append("]"); |
| return (sb.toString()); |
| } |
| } |