/*
* $Header: /home/cvs/jakarta-tomcat-jasper/jasper2/src/share/org/apache/jasper/compiler/TagPluginManager.java,v 1.15 2003/02/15 01:41:43 kinman Exp $
* $Revision: 1.15 $
* $Date: 2003/02/15 01:41:43 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.jasper.compiler;
import java.util.*;
import java.io.*;
import javax.servlet.ServletContext;
import org.apache.jasper.JasperException;
import org.apache.jasper.xmlparser.ParserUtils;
import org.apache.jasper.xmlparser.TreeNode;
import org.apache.jasper.compiler.tagplugin.TagPlugin;
import org.apache.jasper.compiler.tagplugin.TagPluginContext;
/**
* Manages tag plugin optimizations.
* @author Kin-man Chung
*/
public class TagPluginManager {
private static final String TAG_PLUGINS_XML = "/WEB-INF/tagPlugins.xml";
private static final String TAG_PLUGINS_ROOT_ELEM = "tag-plugins";
private boolean initialized = false;
private Hashtable tagPlugins = null;
private ServletContext ctxt;
private PageInfo pageInfo;
public TagPluginManager(ServletContext ctxt) {
this.ctxt = ctxt;
}
public void apply(Node.Nodes page, ErrorDispatcher err, PageInfo pageInfo)
throws JasperException {
init(err);
if (tagPlugins == null || tagPlugins.size() == 0) {
return;
}
this.pageInfo = pageInfo;
page.visit(new Node.Visitor() {
public void visit(Node.CustomTag n)
throws JasperException {
invokePlugin(n);
visitBody(n);
}
});
}
private void init(ErrorDispatcher err) throws JasperException {
if (initialized)
return;
InputStream is = ctxt.getResourceAsStream(TAG_PLUGINS_XML);
if (is == null)
return;
TreeNode root = (new ParserUtils()).parseXMLDocument(TAG_PLUGINS_XML,
is);
if (root == null) {
return;
}
if (!TAG_PLUGINS_ROOT_ELEM.equals(root.getName())) {
err.jspError("jsp.error.plugin.wrongRootElement", TAG_PLUGINS_XML,
TAG_PLUGINS_ROOT_ELEM);
}
tagPlugins = new Hashtable();
Iterator pluginList = root.findChildren("tag-plugin");
while (pluginList.hasNext()) {
TreeNode pluginNode = (TreeNode) pluginList.next();
TreeNode tagClassNode = pluginNode.findChild("tag-class");
if (tagClassNode == null) {
// Error
return;
}
String tagClass = tagClassNode.getBody().trim();
TreeNode pluginClassNode = pluginNode.findChild("plugin-class");
if (pluginClassNode == null) {
// Error
return;
}
String pluginClassStr = pluginClassNode.getBody();
TagPlugin tagPlugin = null;
try {
Class pluginClass = Class.forName(pluginClassStr);
tagPlugin = (TagPlugin) pluginClass.newInstance();
} catch (Exception e) {
throw new JasperException(e);
}
if (tagPlugin == null) {
return;
}
tagPlugins.put(tagClass, tagPlugin);
}
initialized = true;
}
/**
* Invoke tag plugin for the given custom tag, if a plugin exists for
* the custom tag's tag handler.
*
* The given custom tag node will be manipulated by the plugin.
*/
private void invokePlugin(Node.CustomTag n) {
TagPlugin tagPlugin = (TagPlugin)
tagPlugins.get(n.getTagHandlerClass().getName());
if (tagPlugin == null) {
return;
}
TagPluginContext tagPluginContext = new TagPluginContextImpl(n, pageInfo);
n.setTagPluginContext(tagPluginContext);
tagPlugin.doTag(tagPluginContext);
}
static class TagPluginContextImpl implements TagPluginContext {
private Node.CustomTag node;
private Node.Nodes curNodes;
private PageInfo pageInfo;
private HashMap pluginAttributes;
TagPluginContextImpl(Node.CustomTag n, PageInfo pageInfo) {
this.node = n;
this.pageInfo = pageInfo;
curNodes = new Node.Nodes();
n.setAtETag(curNodes);
curNodes = new Node.Nodes();
n.setAtSTag(curNodes);
n.setUseTagPlugin(true);
pluginAttributes = new HashMap();
}
public TagPluginContext getParentContext() {
Node parent = node.getParent();
if (! (parent instanceof Node.CustomTag)) {
return null;
}
return ((Node.CustomTag) parent).getTagPluginContext();
}
public void setAttribute(String key, Object value) {
pluginAttributes.put(key, value);
}
public Object getAttribute(String key) {
return pluginAttributes.get(key);
}
public boolean isScriptless() {
return node.getChildInfo().isScriptless();
}
public boolean isConstantAttribute(String attribute) {
Node.JspAttribute attr = getNodeAttribute(attribute);
if (attr == null)
return false;
return attr.isLiteral();
}
public String getConstantAttribute(String attribute) {
Node.JspAttribute attr = getNodeAttribute(attribute);
if (attr == null)
return null;
return attr.getValue();
}
public boolean isAttributeSpecified(String attribute) {
return getNodeAttribute(attribute) != null;
}
public String getTemporaryVariableName() {
return JspUtil.nextTemporaryVariableName();
}
public void generateImport(String imp) {
pageInfo.addImport(imp);
}
public void generateDeclaration(String id, String text) {
if (pageInfo.isPluginDeclared(id)) {
return;
}
curNodes.add(new Node.Declaration(text, node.getStart(), null));
}
public void generateJavaSource(String sourceCode) {
curNodes.add(new Node.Scriptlet(sourceCode, node.getStart(),
null));
}
public void generateAttribute(String attributeName) {
curNodes.add(new Node.AttributeGenerator(node.getStart(),
attributeName,
node));
}
public void dontUseTagPlugin() {
node.setUseTagPlugin(false);
}
public void generateBody() {
// Since we'll generate the body anyway, this is really a nop,
// except for the fact that it lets us put the Java sources the
// plugins produce in the correct order (w.r.t the body).
curNodes = node.getAtETag();
}
private Node.JspAttribute getNodeAttribute(String attribute) {
Node.JspAttribute[] attrs = node.getJspAttributes();
for (int i=0; i < attrs.length; i++) {
if (attrs[i].getName().equals(attribute)) {
return attrs[i];
}
}
return null;
}
}
}