1 package org.apache.commons.digester3.substitution; 2 3 /* 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 22 import org.apache.commons.digester3.Substitutor; 23 24 import org.xml.sax.Attributes; 25 26 /** 27 * Substitutor implementation that support variable replacement for both attributes and body text. The actual expansion 28 * of variables into text is delegated to {@link VariableExpander} implementations. Supports setting an expander just 29 * for body text or just for attributes. Also supported is setting no expanders for body text and for attributes. 30 * 31 * @since 1.6 32 */ 33 public class VariableSubstitutor 34 extends Substitutor 35 { 36 37 /** 38 * The expander to be used to expand variables in the attributes. Null when no expansion should be performed. 39 */ 40 private final VariableExpander attributesExpander; 41 42 /** 43 * Attributes implementation that (lazily) performs variable substitution. Will be lazily created when needed then 44 * reused. 45 */ 46 private final VariableAttributes variableAttributes; 47 48 /** 49 * The expander to be used to expand variables in the body text. Null when no expansion should be performed. 50 */ 51 private final VariableExpander bodyTextExpander; 52 53 /** 54 * Constructs a Substitutor which uses the same VariableExpander for both body text and attibutes. 55 * 56 * @param expander VariableExpander implementation, null if no substitutions are to be performed 57 */ 58 public VariableSubstitutor( VariableExpander expander ) 59 { 60 this( expander, expander ); 61 } 62 63 /** 64 * Constructs a Substitutor. 65 * 66 * @param attributesExpander VariableExpander implementation to be used for attributes, null if no attribute 67 * substitutions are to be performed 68 * @param bodyTextExpander VariableExpander implementation to be used for bodyTextExpander, null if no attribute 69 * substitutions are to be performed 70 */ 71 public VariableSubstitutor( VariableExpander attributesExpander, VariableExpander bodyTextExpander ) 72 { 73 this.attributesExpander = attributesExpander; 74 this.bodyTextExpander = bodyTextExpander; 75 variableAttributes = new VariableAttributes(); 76 } 77 78 /** 79 * {@inheritDoc} 80 */ 81 @Override 82 public Attributes substitute( Attributes attributes ) 83 { 84 Attributes results = attributes; 85 if ( attributesExpander != null ) 86 { 87 variableAttributes.init( attributes, attributesExpander ); 88 results = variableAttributes; 89 } 90 return results; 91 } 92 93 /** 94 * {@inheritDoc} 95 */ 96 @Override 97 public String substitute( String bodyText ) 98 { 99 String result = bodyText; 100 if ( bodyTextExpander != null ) 101 { 102 result = bodyTextExpander.expand( bodyText ); 103 } 104 return result; 105 } 106 107 }