001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 /*
019 * $Id: SerializerSwitcher.java 468645 2006-10-28 06:57:24Z minchau $
020 */
021 package org.apache.xalan.transformer;
022
023 import java.io.OutputStream;
024 import java.io.Writer;
025 import java.util.Properties;
026
027 import javax.xml.transform.OutputKeys;
028 import javax.xml.transform.TransformerException;
029
030 import org.apache.xml.serializer.Serializer;
031 import org.apache.xml.serializer.SerializerFactory;
032 import org.apache.xml.serializer.Method;
033 import org.apache.xalan.templates.OutputProperties;
034
035 import org.xml.sax.ContentHandler;
036
037 /**
038 * This is a helper class that decides if Xalan needs to switch
039 * serializers, based on the first output element.
040 */
041 public class SerializerSwitcher
042 {
043
044 /**
045 * Switch to HTML serializer if element is HTML
046 *
047 *
048 * @param transformer Non-null transformer instance
049 * @param ns Namespace URI of the element
050 * @param localName Local part of name of element
051 *
052 * @throws TransformerException
053 */
054 public static void switchSerializerIfHTML(
055 TransformerImpl transformer, String ns, String localName)
056 throws TransformerException
057 {
058
059 if (null == transformer)
060 return;
061
062 if (((null == ns) || (ns.length() == 0))
063 && localName.equalsIgnoreCase("html"))
064 {
065 // System.out.println("transformer.getOutputPropertyNoDefault(OutputKeys.METHOD): "+
066 // transformer.getOutputPropertyNoDefault(OutputKeys.METHOD));
067 // Access at level of hashtable to see if the method has been set.
068 if (null != transformer.getOutputPropertyNoDefault(OutputKeys.METHOD))
069 return;
070
071 // Getting the output properties this way won't cause a clone of
072 // the properties.
073 Properties prevProperties = transformer.getOutputFormat().getProperties();
074
075 // We have to make sure we get an output properties with the proper
076 // defaults for the HTML method. The easiest way to do this is to
077 // have the OutputProperties class do it.
078 OutputProperties htmlOutputProperties = new OutputProperties(Method.HTML);
079
080 htmlOutputProperties.copyFrom(prevProperties, true);
081 Properties htmlProperties = htmlOutputProperties.getProperties();
082
083 try
084 {
085 // Serializer oldSerializer = transformer.getSerializer();
086 Serializer oldSerializer = null;
087
088 if (null != oldSerializer)
089 {
090 Serializer serializer =
091 SerializerFactory.getSerializer(htmlProperties);
092
093 Writer writer = oldSerializer.getWriter();
094
095 if (null != writer)
096 serializer.setWriter(writer);
097 else
098 {
099 OutputStream os = oldSerializer.getOutputStream();
100
101 if (null != os)
102 serializer.setOutputStream(os);
103 }
104
105 // transformer.setSerializer(serializer);
106
107 ContentHandler ch = serializer.asContentHandler();
108
109 transformer.setContentHandler(ch);
110 }
111 }
112 catch (java.io.IOException e)
113 {
114 throw new TransformerException(e);
115 }
116 }
117 }
118
119 /**
120 * Get the value of a property, without using the default properties. This
121 * can be used to test if a property has been explicitly set by the stylesheet
122 * or user.
123 *
124 * @param name The property name, which is a fully-qualified URI.
125 *
126 * @return The value of the property, or null if not found.
127 *
128 * @throws IllegalArgumentException If the property is not supported,
129 * and is not namespaced.
130 */
131 private static String getOutputPropertyNoDefault(String qnameString, Properties props)
132 throws IllegalArgumentException
133 {
134 String value = (String)props.get(qnameString);
135
136 return value;
137 }
138
139 /**
140 * Switch to HTML serializer if element is HTML
141 *
142 *
143 * @param ns Namespace URI of the element
144 * @param localName Local part of name of element
145 *
146 * @throws TransformerException
147 * @return new contentHandler.
148 */
149 public static Serializer switchSerializerIfHTML(
150 String ns, String localName, Properties props, Serializer oldSerializer)
151 throws TransformerException
152 {
153 Serializer newSerializer = oldSerializer;
154
155 if (((null == ns) || (ns.length() == 0))
156 && localName.equalsIgnoreCase("html"))
157 {
158 // System.out.println("transformer.getOutputPropertyNoDefault(OutputKeys.METHOD): "+
159 // transformer.getOutputPropertyNoDefault(OutputKeys.METHOD));
160 // Access at level of hashtable to see if the method has been set.
161 if (null != getOutputPropertyNoDefault(OutputKeys.METHOD, props))
162 return newSerializer;
163
164 // Getting the output properties this way won't cause a clone of
165 // the properties.
166 Properties prevProperties = props;
167
168 // We have to make sure we get an output properties with the proper
169 // defaults for the HTML method. The easiest way to do this is to
170 // have the OutputProperties class do it.
171 OutputProperties htmlOutputProperties = new OutputProperties(Method.HTML);
172
173 htmlOutputProperties.copyFrom(prevProperties, true);
174 Properties htmlProperties = htmlOutputProperties.getProperties();
175
176 // try
177 {
178 if (null != oldSerializer)
179 {
180 Serializer serializer =
181 SerializerFactory.getSerializer(htmlProperties);
182
183 Writer writer = oldSerializer.getWriter();
184
185 if (null != writer)
186 serializer.setWriter(writer);
187 else
188 {
189 OutputStream os = serializer.getOutputStream();
190
191 if (null != os)
192 serializer.setOutputStream(os);
193 }
194 newSerializer = serializer;
195 }
196 }
197 // catch (java.io.IOException e)
198 // {
199 // throw new TransformerException(e);
200 // }
201 }
202 return newSerializer;
203 }
204
205 }