/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: PipeDocument.java,v 1.9 2004/12/13 19:59:18 joannet Exp $
*/
package org.apache.xalan.lib;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;
import java.util.Vector;
import javax.xml.transform.Templates;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamSource;
import org.apache.xalan.extensions.XSLProcessorContext;
import org.apache.xalan.templates.AVT;
import org.apache.xalan.templates.ElemExtensionCall;
import org.apache.xalan.templates.ElemLiteralResult;
import org.apache.xalan.transformer.TransformerImpl;
import org.apache.xml.utils.SystemIDResolver;
import org.apache.xpath.XPathContext;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLReaderFactory;
/**
*/
// Imported Serializer classes
import org.apache.xml.serializer.Serializer;
import org.apache.xml.serializer.SerializerFactory;
/**
* PipeDocument is a Xalan extension element to set stylesheet params and pipes an XML
* document through a series of 1 or more stylesheets.
* PipeDocument is invoked from a stylesheet as the {@link #pipeDocument pipeDocument extension element}.
*
* It is accessed by specifying a namespace URI as follows:
* <pre>
* xmlns:pipe="http://xml.apache.org/xalan/PipeDocument"
* </pre>
*
* @author Donald Leslie
*/
public class PipeDocument
{
/**
* Extension element for piping an XML document through a series of 1 or more transformations.
*
* <pre>Common usage pattern: A stylesheet transforms a listing of documents to be
* transformed into a TOC. For each document in the listing calls the pipeDocument
* extension element to pipe that document through a series of 1 or more stylesheets
* to the desired output document.
*
* Syntax:
* <xsl:stylesheet version="1.0"
* xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
* xmlns:pipe="http://xml.apache.org/xalan/PipeDocument"
* extension-element-prefixes="pipe">
* ...
* <pipe:pipeDocument source="source.xml" target="target.xml">
* <stylesheet href="ss1.xsl">
* <param name="param1" value="value1"/>
* </stylesheet>
* <stylesheet href="ss2.xsl">
* <param name="param1" value="value1"/>
* <param name="param2" value="value2"/>
* </stylesheet>
* <stylesheet href="ss1.xsl"/>
* </pipe:pipeDocument>
*
* Notes:</pre>
* <ul>
* <li>The base URI for the source attribute is the XML "listing" document.<li/>
* <li>The target attribute is taken as is (base is the current user directory).<li/>
* <li>The stylsheet containg the extension element is the base URI for the
* stylesheet hrefs.<li/>
* </ul>
*/
public void pipeDocument(XSLProcessorContext context, ElemExtensionCall elem)
throws TransformerException, TransformerConfigurationException,
SAXException, IOException, FileNotFoundException
{
SAXTransformerFactory saxTFactory = (SAXTransformerFactory) TransformerFactory.newInstance();
// XML doc to transform.
String source = elem.getAttribute("source",
context.getContextNode(),
context.getTransformer());
TransformerImpl transImpl = context.getTransformer();
//Base URI for input doc, so base for relative URI to XML doc to transform.
String baseURLOfSource = transImpl.getBaseURLOfSource();
// Absolute URI for XML doc to transform.
String absSourceURL = SystemIDResolver.getAbsoluteURI(source, baseURLOfSource);
// Transformation target
String target = elem.getAttribute("target",
context.getContextNode(),
context.getTransformer());
XPathContext xctxt = context.getTransformer().getXPathContext();
int xt = xctxt.getDTMHandleFromNode(context.getContextNode());
// Get System Id for stylesheet; to be used to resolve URIs to other stylesheets.
String sysId = elem.getSystemId();
NodeList ssNodes = null;
NodeList paramNodes = null;
Node ssNode = null;
Node paramNode = null;
if (elem.hasChildNodes())
{
ssNodes = elem.getChildNodes();
// Vector to contain TransformerHandler for each stylesheet.
Vector vTHandler = new Vector(ssNodes.getLength());
// The child nodes of an extension element node are instances of
// ElemLiteralResult, which requires does not fully support the standard
// Node interface. Accordingly, some special handling is required (see below)
// to get attribute values.
for (int i = 0; i < ssNodes.getLength(); i++)
{
ssNode = ssNodes.item(i);
if (ssNode.getNodeType() == Node.ELEMENT_NODE
&& ((Element)ssNode).getTagName().equals("stylesheet")
&& ssNode instanceof ElemLiteralResult)
{
AVT avt = ((ElemLiteralResult)ssNode).getLiteralResultAttribute("href");
String href = avt.evaluate(xctxt,xt, elem);
String absURI = SystemIDResolver.getAbsoluteURI(href, sysId);
Templates tmpl = saxTFactory.newTemplates(new StreamSource(absURI));
TransformerHandler tHandler = saxTFactory.newTransformerHandler(tmpl);
Transformer trans = tHandler.getTransformer();
// AddTransformerHandler to vector
vTHandler.addElement(tHandler);
paramNodes = ssNode.getChildNodes();
for (int j = 0; j < paramNodes.getLength(); j++)
{
paramNode = paramNodes.item(j);
if (paramNode.getNodeType() == Node.ELEMENT_NODE
&& ((Element)paramNode).getTagName().equals("param")
&& paramNode instanceof ElemLiteralResult)
{
avt = ((ElemLiteralResult)paramNode).getLiteralResultAttribute("name");
String pName = avt.evaluate(xctxt,xt, elem);
avt = ((ElemLiteralResult)paramNode).getLiteralResultAttribute("value");
String pValue = avt.evaluate(xctxt,xt, elem);
trans.setParameter(pName, pValue);
}
}
}
}
usePipe(vTHandler, absSourceURL, target);
}
}
/**
* Uses a Vector of TransformerHandlers to pipe XML input document through
* a series of 1 or more transformations. Called by {@link #pipeDocument}.
*
* @param vTHandler Vector of Transformation Handlers (1 per stylesheet).
* @param source absolute URI to XML input
* @param target absolute path to transformation output.
*/
public void usePipe(Vector vTHandler, String source, String target)
throws TransformerException, TransformerConfigurationException,
FileNotFoundException, IOException, SAXException, SAXNotRecognizedException
{
XMLReader reader = XMLReaderFactory.createXMLReader();
TransformerHandler tHFirst = (TransformerHandler)vTHandler.firstElement();
reader.setContentHandler(tHFirst);
reader.setProperty("http://xml.org/sax/properties/lexical-handler", tHFirst);
for (int i = 1; i < vTHandler.size(); i++)
{
TransformerHandler tHFrom = (TransformerHandler)vTHandler.elementAt(i-1);
TransformerHandler tHTo = (TransformerHandler)vTHandler.elementAt(i);
tHFrom.setResult(new SAXResult(tHTo));
}
TransformerHandler tHLast = (TransformerHandler)vTHandler.lastElement();
Transformer trans = tHLast.getTransformer();
Properties outputProps = trans.getOutputProperties();
Serializer serializer = SerializerFactory.getSerializer(outputProps);
FileOutputStream out = new FileOutputStream(target);
try
{
serializer.setOutputStream(out);
tHLast.setResult(new SAXResult(serializer.asContentHandler()));
reader.parse(source);
}
finally
{
// Always clean up the FileOutputStream,
// even if an exception was thrown in the try block
if (out != null)
out.close();
}
}
}