| 1 | package org.apache.velocity.runtime.parser.node; |
| 2 | |
| 3 | /* |
| 4 | * Copyright 2000-2001,2004 The Apache Software Foundation. |
| 5 | * |
| 6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | * you may not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | */ |
| 18 | |
| 19 | import org.apache.velocity.context.InternalContextAdapter; |
| 20 | import org.apache.velocity.runtime.parser.Parser; |
| 21 | |
| 22 | import java.io.StringWriter; |
| 23 | import java.io.BufferedReader; |
| 24 | import java.io.StringReader; |
| 25 | |
| 26 | import org.apache.velocity.runtime.RuntimeConstants; |
| 27 | |
| 28 | /** |
| 29 | * ASTStringLiteral support. Will interpolate! |
| 30 | * |
| 31 | * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> |
| 32 | * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> |
| 33 | * @version $Id: ASTStringLiteral.java,v 1.17.4.1 2004/03/03 23:22:59 geirm Exp $ |
| 34 | */ |
| 35 | public class ASTStringLiteral extends SimpleNode |
| 36 | { |
| 37 | /* cache the value of the interpolation switch */ |
| 38 | private boolean interpolate = true; |
| 39 | private SimpleNode nodeTree = null; |
| 40 | private String image = ""; |
| 41 | private String interpolateimage = ""; |
| 42 | |
| 43 | public ASTStringLiteral(int id) |
| 44 | { |
| 45 | super(id); |
| 46 | } |
| 47 | |
| 48 | public ASTStringLiteral(Parser p, int id) |
| 49 | { |
| 50 | super(p, id); |
| 51 | } |
| 52 | |
| 53 | /** |
| 54 | * init : we don't have to do much. Init the tree (there |
| 55 | * shouldn't be one) and then see if interpolation is turned on. |
| 56 | */ |
| 57 | public Object init(InternalContextAdapter context, Object data) |
| 58 | throws Exception |
| 59 | { |
| 60 | /* |
| 61 | * simple habit... we prollie don't have an AST beneath us |
| 62 | */ |
| 63 | |
| 64 | super.init(context, data); |
| 65 | |
| 66 | /* |
| 67 | * the stringlit is set at template parse time, so we can |
| 68 | * do this here for now. if things change and we can somehow |
| 69 | * create stringlits at runtime, this must |
| 70 | * move to the runtime execution path |
| 71 | * |
| 72 | * so, only if interpolation is turned on AND it starts |
| 73 | * with a " AND it has a directive or reference, then we |
| 74 | * can interpolate. Otherwise, don't bother. |
| 75 | */ |
| 76 | |
| 77 | interpolate = rsvc.getBoolean(RuntimeConstants.INTERPOLATE_STRINGLITERALS , true) |
| 78 | && getFirstToken().image.startsWith("\"") |
| 79 | && ((getFirstToken().image.indexOf('$') != -1) |
| 80 | || (getFirstToken().image.indexOf('#') != -1)); |
| 81 | |
| 82 | /* |
| 83 | * get the contents of the string, minus the '/" at each end |
| 84 | */ |
| 85 | |
| 86 | image = getFirstToken().image.substring(1, |
| 87 | getFirstToken().image.length() - 1); |
| 88 | |
| 89 | /* |
| 90 | * tack a space on the end (dreaded <MORE> kludge) |
| 91 | */ |
| 92 | |
| 93 | interpolateimage = image + " "; |
| 94 | |
| 95 | if (interpolate) |
| 96 | { |
| 97 | /* |
| 98 | * now parse and init the nodeTree |
| 99 | */ |
| 100 | BufferedReader br = new BufferedReader(new StringReader(interpolateimage)); |
| 101 | |
| 102 | /* |
| 103 | * it's possible to not have an initialization context - or we don't |
| 104 | * want to trust the caller - so have a fallback value if so |
| 105 | * |
| 106 | * Also, do *not* dump the VM namespace for this template |
| 107 | */ |
| 108 | |
| 109 | nodeTree = rsvc.parse(br, (context != null) ? |
| 110 | context.getCurrentTemplateName() : "StringLiteral", false); |
| 111 | |
| 112 | /* |
| 113 | * init with context. It won't modify anything |
| 114 | */ |
| 115 | |
| 116 | nodeTree.init(context, rsvc); |
| 117 | } |
| 118 | |
| 119 | return data; |
| 120 | } |
| 121 | |
| 122 | /** Accept the visitor. **/ |
| 123 | public Object jjtAccept(ParserVisitor visitor, Object data) |
| 124 | { |
| 125 | return visitor.visit(this, data); |
| 126 | } |
| 127 | |
| 128 | /** |
| 129 | * renders the value of the string literal |
| 130 | * If the properties allow, and the string literal contains a $ or a # |
| 131 | * the literal is rendered against the context |
| 132 | * Otherwise, the stringlit is returned. |
| 133 | */ |
| 134 | public Object value(InternalContextAdapter context) |
| 135 | { |
| 136 | if (interpolate) |
| 137 | { |
| 138 | try |
| 139 | { |
| 140 | /* |
| 141 | * now render against the real context |
| 142 | */ |
| 143 | |
| 144 | StringWriter writer = new StringWriter(); |
| 145 | nodeTree.render(context, writer); |
| 146 | |
| 147 | /* |
| 148 | * and return the result as a String |
| 149 | */ |
| 150 | |
| 151 | String ret = writer.toString(); |
| 152 | |
| 153 | /* |
| 154 | * remove the space from the end (dreaded <MORE> kludge) |
| 155 | */ |
| 156 | |
| 157 | return ret.substring(0, ret.length() - 1); |
| 158 | } |
| 159 | catch(Exception e) |
| 160 | { |
| 161 | /* |
| 162 | * eh. If anything wrong, just punt |
| 163 | * and output the literal |
| 164 | */ |
| 165 | rsvc.error("Error in interpolating string literal : " + e); |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | /* |
| 170 | * ok, either not allowed to interpolate, there wasn't |
| 171 | * a ref or directive, or we failed, so |
| 172 | * just output the literal |
| 173 | */ |
| 174 | |
| 175 | return image; |
| 176 | } |
| 177 | } |