001 /*
002 * This file is part of the Echo Point Project. This project is a collection
003 * of Components that have extended the Echo Web Application Framework.
004 *
005 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
006 *
007 * The contents of this file are subject to the Mozilla Public License Version
008 * 1.1 (the "License"); you may not use this file except in compliance with
009 * the License. You may obtain a copy of the License at
010 * http://www.mozilla.org/MPL/
011 *
012 * Software distributed under the License is distributed on an "AS IS" basis,
013 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
014 * for the specific language governing rights and limitations under the
015 * License.
016 *
017 * Alternatively, the contents of this file may be used under the terms of
018 * either the GNU General Public License Version 2 or later (the "GPL"), or
019 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
020 * in which case the provisions of the GPL or the LGPL are applicable instead
021 * of those above. If you wish to allow use of your version of this file only
022 * under the terms of either the GPL or the LGPL, and not to allow others to
023 * use your version of this file under the terms of the MPL, indicate your
024 * decision by deleting the provisions above and replace them with the notice
025 * and other provisions required by the GPL or the LGPL. If you do not delete
026 * the provisions above, a recipient may use your version of this file under
027 * the terms of any one of the MPL, the GPL or the LGPL.
028 */
029 package echopoint.template.ui;
030
031 import java.io.InputStream;
032 import java.io.InputStreamReader;
033 import java.io.BufferedReader;
034 import java.io.IOException;
035
036 import javax.xml.parsers.DocumentBuilder;
037 import javax.xml.parsers.DocumentBuilderFactory;
038 import javax.xml.parsers.ParserConfigurationException;
039
040 import nextapp.echo.webcontainer.Connection;
041
042 import org.w3c.dom.Document;
043 import org.w3c.dom.Element;
044 import org.xml.sax.InputSource;
045
046 import echopoint.template.TemplateCompilerHints;
047 import echopoint.template.TemplateDataSource;
048
049 /**
050 * <code>XHTMLTemplateCompiler</code> can compile source XHTML template data
051 * into.. well a XHTML DOM Element.
052 */
053
054 public class XHTMLTemplateCompiler implements TemplateCompiler {
055
056 /**
057 * ThreadLocal cache of validating <code>DocumentBuilder</code> instances.
058 */
059 private static final ThreadLocal nonvalidatingDocumentBuilders = new ThreadLocal() {
060
061 /**
062 * @see java.lang.ThreadLocal#initialValue()
063 */
064 protected Object initialValue() {
065 return buildDocumentBuilder(null);
066 }
067 };
068
069 /**
070 * Called to return a <code>DocumentBuilder</code> based on the compiler
071 * hints.
072 *
073 * @param compilerHints -
074 * the hints for the factory used to build the
075 * <code>DocumentBuilder</code> which can be null.
076 * @return a <code>DocumentBuilder</code>
077 */
078 protected static final DocumentBuilder buildDocumentBuilder(TemplateCompilerHints compilerHints) {
079 try {
080 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
081 if (compilerHints == null) {
082 factory.setNamespaceAware(true);
083 factory.setValidating(false);
084 factory.setAttribute("http://apache.org/xml/features/nonvalidating/load-external-dtd", Boolean.valueOf(false));
085 } else {
086 factory.setCoalescing(compilerHints.isCoalescing());
087 factory.setExpandEntityReferences(compilerHints.isExpandEntityReferences());
088 factory.setIgnoringComments(compilerHints.isIgnoringComments());
089 factory.setIgnoringElementContentWhitespace(compilerHints.isIgnoringElementContentWhitespace());
090 factory.setNamespaceAware(compilerHints.isNamespaceAware());
091 factory.setValidating(compilerHints.isValidating());
092 // custom attributes
093 String[] attrNames = compilerHints.getAttributeNames();
094 if (attrNames != null) {
095 for (int i = 0; i < attrNames.length; i++) {
096 Object value = compilerHints.getAttributeValue(attrNames[i]);
097 factory.setAttribute(attrNames[i], value);
098 }
099 }
100 }
101 DocumentBuilder builder = factory.newDocumentBuilder();
102 return builder;
103 } catch (ParserConfigurationException ex) {
104 throw new RuntimeException(ex);
105 }
106 }
107
108 /**
109 * Retrieves a thread-specific non validating <code>DocumentBuilder</code>.
110 *
111 * @return the <code>DocumentBuilder</code> serving the current thread.
112 */
113 protected static DocumentBuilder getNonValidatingDocumentBuilder() {
114 return (DocumentBuilder) nonvalidatingDocumentBuilders.get();
115 }
116
117 /**
118 * @see echopoint.template.ui.TemplateCompiler#compileTemplateDataIntoXHTML(nextapp.echo.webcontainer.RenderContext,
119 * echopoint.template.TemplateDataSource)
120 */
121 public Element compileTemplateDataIntoXHTML(Connection c, TemplateDataSource tds) throws Exception {
122 return compileXHTML(tds.getInputStream(), tds);
123 }
124
125 public String templateDataAsString(Connection c, TemplateDataSource tds) throws Exception {
126 BufferedReader reader = new BufferedReader(new InputStreamReader(tds.getInputStream()));
127 StringBuilder sb = new StringBuilder();
128
129 String line = null;
130 try {
131 while ((line = reader.readLine()) != null) {
132 sb.append(line + "\n");
133 }
134 } finally {
135 tds.getInputStream().close();
136 }
137
138 return sb.toString();
139
140 }
141
142
143 /**
144 * This does the actual compiling of a stream of XHTML into a XHTML DOM
145 * Element.
146 *
147 * @param inputStream -
148 * this must be a stream of XHTML data
149 * @param tds -
150 * -
151 * @return
152 * @throws Exception
153 */
154 protected Element compileXHTML(InputStream inputStream, TemplateDataSource tds) throws Exception {
155 long startMS = System.currentTimeMillis();
156
157 String characterEncoding = tds.getCharacterEncoding();
158 TemplateCompilerHints compilerHints = tds.getCompilerHints();
159
160 InputStreamReader isr;
161 if (characterEncoding != null) {
162 isr = new InputStreamReader(inputStream, characterEncoding);
163 } else {
164 isr = new InputStreamReader(inputStream);
165 }
166
167 InputSource inputSource = new InputSource();
168 inputSource.setCharacterStream(isr);
169 inputSource.setByteStream(inputStream);
170 inputSource.setEncoding(characterEncoding);
171
172 try {
173 DocumentBuilder docBuilder = null;
174 if (compilerHints == null) {
175 docBuilder = getNonValidatingDocumentBuilder();
176 } else {
177 docBuilder = buildDocumentBuilder(compilerHints);
178 }
179 Document document = docBuilder.parse(inputSource);
180 Element documentElement = document.getDocumentElement();
181
182 long compileMS = System.currentTimeMillis() - startMS;
183 if (compileMS == 0)
184 ;
185 return documentElement;
186 } catch (RuntimeException rte) {
187 throw rte;
188 }
189 }
190
191 }