/*
* $Header: /home/cvs/jakarta-commons-sandbox/jelly/src/java/org/apache/commons/jelly/impl/TagScript.java,v 1.19 2002/08/19 21:38:09 jstrachan Exp $
* $Revision: 1.19 $
* $Date: 2002/08/19 21:38:09 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2002 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", "Commons", 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/>.
*
* $Id: TagScript.java,v 1.19 2002/08/19 21:38:09 jstrachan Exp $
*/
package org.apache.commons.jelly.impl;
import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.jelly.CompilableTag;
import org.apache.commons.jelly.JellyContext;
import org.apache.commons.jelly.JellyException;
import org.apache.commons.jelly.DynaTag;
import org.apache.commons.jelly.Script;
import org.apache.commons.jelly.Tag;
import org.apache.commons.jelly.XMLOutput;
import org.apache.commons.jelly.expression.Expression;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
/**
* <p><code>TagScript</code> abstract base class for a
* script that evaluates a custom tag.</p>
*
* <b>Note</b> that this class should be re-entrant and used
* concurrently by multiple threads.
*
* @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
* @version $Revision: 1.19 $
*/
public abstract class TagScript implements Script {
/** The Log to which logging calls will be made. */
private static final Log log = LogFactory.getLog(TagScript.class);
/**
* Thread local storage for the tag used by the current thread.
* This allows us to pool tag instances, per thread to reduce object construction
* over head, if we need it.
*
* Note that we could use the stack and create a new tag for each invocation
* if we made a slight change to the Script API to pass in the parent tag.
*/
private ThreadLocal tagHolder = new ThreadLocal();
/** The attribute expressions that are created */
protected Map attributes = new Hashtable();
/** the optional namespaces Map of prefix -> URI */
private Map namespacesMap;
/** the Jelly file which caused the problem */
private String fileName;
/** the tag name which caused the problem */
private String elementName;
/** the line number of the tag */
private int lineNumber = -1;
/** the column number of the tag */
private int columnNumber = -1;
/** the factory of Tag instances */
private TagFactory tagFactory;
/** the body script used for this tag */
private Script tagBody;
/** the parent TagScript */
private TagScript parent;
/**
* @return a new TagScript based on whether
* the given Tag class is a bean tag or DynaTag
*/
public static TagScript newInstance(Class tagClass) {
TagFactory factory = new DefaultTagFactory(tagClass);
if ( DynaTag.class.isAssignableFrom(tagClass) ) {
return new DynaTagScript(factory);
}
return new BeanTagScript(factory);
}
public TagScript() {
}
public TagScript(TagFactory tagFactory) {
this.tagFactory = tagFactory;
}
public String toString() {
return super.toString() + "[tag=" + elementName + ";at=" + lineNumber + ":" + columnNumber + "]";
}
/**
* Compiles the tags body
*/
public Script compile() throws Exception {
if (tagBody != null) {
tagBody = tagBody.compile();
}
return this;
}
/**
* Sets the optional namespaces prefix -> URI map
*/
public void setNamespacesMap(Map namespacesMap) {
// lets check that this is a thread-safe map
if ( ! (namespacesMap instanceof Hashtable) ) {
namespacesMap = new Hashtable( namespacesMap );
}
this.namespacesMap = namespacesMap;
}
/**
* Configures this TagScript from the SAX Locator, setting the column
* and line numbers
*/
public void setLocator(Locator locator) {
setLineNumber( locator.getLineNumber() );
setColumnNumber( locator.getColumnNumber() );
}
/** Add an initialization attribute for the tag.
* This method must be called after the setTag() method
*/
public void addAttribute(String name, Expression expression) {
if (log.isDebugEnabled()) {
log.debug("adding attribute name: " + name + " expression: " + expression);
}
attributes.put(name, expression);
}
// Properties
//-------------------------------------------------------------------------
/**
* @return the tag to be evaluated, creating it lazily if required.
*/
public Tag getTag() throws Exception {
Tag tag = (Tag) tagHolder.get();
if ( tag == null ) {
tag = createTag();
if ( tag != null ) {
configureTag(tag);
tagHolder.set(tag);
}
}
return tag;
}
/**
* Returns the Factory of Tag instances.
* @return the factory
*/
public TagFactory getTagFactory() {
return tagFactory;
}
/**
* Sets the Factory of Tag instances.
* @param tagFactory The factory to set
*/
public void setTagFactory(TagFactory tagFactory) {
this.tagFactory = tagFactory;
}
/**
* Returns the parent.
* @return TagScript
*/
public TagScript getParent() {
return parent;
}
/**
* Returns the tagBody.
* @return Script
*/
public Script getTagBody() {
return tagBody;
}
/**
* Sets the parent.
* @param parent The parent to set
*/
public void setParent(TagScript parent) {
this.parent = parent;
}
/**
* Sets the tagBody.
* @param tagBody The tagBody to set
*/
public void setTagBody(Script tagBody) {
this.tagBody = tagBody;
}
/**
* @return the Jelly file which caused the problem
*/
public String getFileName() {
return fileName;
}
/**
* Sets the Jelly file which caused the problem
*/
public void setFileName(String fileName) {
this.fileName = fileName;
}
/**
* @return the element name which caused the problem
*/
public String getElementName() {
return elementName;
}
/**
* Sets the element name which caused the problem
*/
public void setElementName(String elementName) {
this.elementName = elementName;
}
/**
* @return the line number of the tag
*/
public int getLineNumber() {
return lineNumber;
}
/**
* Sets the line number of the tag
*/
public void setLineNumber(int lineNumber) {
this.lineNumber = lineNumber;
}
/**
* @return the column number of the tag
*/
public int getColumnNumber() {
return columnNumber;
}
/**
* Sets the column number of the tag
*/
public void setColumnNumber(int columnNumber) {
this.columnNumber = columnNumber;
}
// Implementation methods
//-------------------------------------------------------------------------
/**
* Factory method to create a new Tag instance.
* The default implementation is to delegate to the TagFactory
*/
protected Tag createTag() throws Exception {
if ( tagFactory != null) {
return tagFactory.createTag();
}
return null;
}
/**
* Compiles a newly created tag if required, sets its parent and body.
*/
protected void configureTag(Tag tag) throws Exception {
if (tag instanceof CompilableTag) {
((CompilableTag) tag).compile();
}
Tag parentTag = null;
if ( parent != null ) {
parentTag = parent.getTag();
}
tag.setParent( parentTag );
tag.setBody( tagBody );
}
/**
* Flushes the current cached tag so that it will be created, lazily, next invocation
*/
protected void clearTag() {
tagHolder.set(null);
}
/**
* Allows the script to set the tag instance to be used, such as in a StaticTagScript
* when a StaticTag is switched with a DynamicTag
*/
protected void setTag(Tag tag) {
tagHolder.set(tag);
}
/**
* Output the new namespace prefixes used for this element
*/
protected void startNamespacePrefixes(XMLOutput output) throws SAXException {
if ( namespacesMap != null ) {
for ( Iterator iter = namespacesMap.entrySet().iterator(); iter.hasNext(); ) {
Map.Entry entry = (Map.Entry) iter.next();
String prefix = (String) entry.getKey();
String uri = (String) entry.getValue();
output.startPrefixMapping(prefix, uri);
}
}
}
/**
* End the new namespace prefixes mapped for the current element
*/
protected void endNamespacePrefixes(XMLOutput output) throws SAXException {
if ( namespacesMap != null ) {
for ( Iterator iter = namespacesMap.keySet().iterator(); iter.hasNext(); ) {
String prefix = (String) iter.next();
output.endPrefixMapping(prefix);
}
}
}
/**
* Converts the given value to the required type.
*
* @param value is the value to be converted. This will not be null
* @param requiredType the type that the value should be converted to
*/
protected Object convertType(Object value, Class requiredType)
throws Exception {
if (requiredType.isInstance(value)) {
return value;
}
if (value instanceof String) {
return ConvertUtils.convert((String) value, requiredType);
}
return value;
}
/**
* A helper method to handle this non-Jelly exception.
* This method will rethrow the exception, wrapped in a JellyException
* while adding line number information etc.
*/
protected void handleException(Exception e) throws Exception {
log.error( "Caught exception: " + e, e );
if ( e instanceof JellyException )
{
e.fillInStackTrace();
throw e;
}
if ( e instanceof InvocationTargetException)
{
throw new JellyException( ((InvocationTargetException)e).getTargetException(),
fileName,
elementName,
columnNumber,
lineNumber );
}
throw new JellyException(e, fileName, elementName, columnNumber, lineNumber);
}
/**
* Creates a new Jelly exception, adorning it with location information
*/
protected JellyException createJellyException(String reason) {
return new JellyException(
reason, fileName, elementName, columnNumber, lineNumber
);
}
/**
* Creates a new Jelly exception, adorning it with location information
*/
protected JellyException createJellyException(String reason, Exception cause) {
if ( cause instanceof JellyException )
{
return (JellyException) cause;
}
if ( cause instanceof InvocationTargetException)
{
return new JellyException(
reason,
((InvocationTargetException)cause).getTargetException(),
fileName,
elementName,
columnNumber,
lineNumber);
}
return new JellyException(
reason, cause, fileName, elementName, columnNumber, lineNumber
);
}
/**
* A helper method to handle this Jelly exception.
* This method adorns the JellyException with location information
* such as adding line number information etc.
*/
protected void handleException(JellyException e) throws Exception {
if (e.getLineNumber() == -1) {
e.setColumnNumber(columnNumber);
e.setLineNumber(lineNumber);
}
if ( e.getFileName() == null ) {
e.setFileName( fileName );
}
if ( e.getElementName() == null ) {
e.setElementName( elementName );
}
throw e;
}
}