fop-1_1/src/documentation/content/xdocs/trunk/intermediate.xml - xmlgraphics-fop - Git at Google

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 <!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "http://forrest.apache.org/dtd/document-v20.dtd">
 <document>
   <header>
     <title>Apache™ FOP: Intermediate Format</title>
     <version>$Revision$</version>
   </header>
   <body>
     <note>
       Please note that the intermediate formats described here are
       <strong>advanced features</strong> and can be ignored by most users of Apache FOP.
     </note>
     <section id="introduction">
       <title>Introduction</title>
       <p>
         Apache™ FOP now provides two different so-called intermediate formats. The first one
         (let's call it the area tree XML format) is basically a 1:1 XML representation of FOP's
         area tree as generated by the layout engine. The area tree is conceptually defined in the
         <a href="http://www.w3.org/TR/2001/REC-xsl-20011015/slice1.html#section-N742-Formatting">XSL-FO specification in chapter 1.1.2</a>.
         Even though the area tree is mentioned in the XSL-FO specification, this part is not
         standardized. Therefore, the area tree XML format is a FOP-proprietary XML file format.
         The area tree XML can be generated through the area tree XML Renderer (the XMLRenderer).
       </p>
       <p>
         The second intermediate format (which we shall name exactly like this: the intermediate
         format)
         is a recent addition which tries to meet a slightly different set of goals. It is highly
         optimized for speed.
       </p>
       <p>
         The intermediate format can be used to generate intermediate documents that are modified
         before they are finally rendered to their ultimate output format. Modifications include
         adjusting and changing trait values, adding or modifying area objects, inserting prefabricated
         pages, overlays, imposition (n-up, rotation, scaling etc.). Multiple IF files can be combined
         to a single output file.
       </p>
     </section>
     <section id="which-if">
       <title>Which Intermediate Format to choose?</title>
       <p>
         Both formats have their use cases, so the choice you will make will depend on your
         particular situation. Here is a list of strengths and use cases for both formats:
       </p>
       <section id="strengths-at">
         <title>Area Tree XML (AT XML)</title>
         <ul>
           <li>1:1 representation of FOP's area tree in XML.</li>
           <li>Contains more structure information than the new intermediate format.</li>
           <li>Used in FOP's layout engine test suite for regression testing.</li>
         </ul>
       </section>
       <section id="strengths-if">
         <title>Intermediate Format (IF)</title>
         <ul>
           <li>Highly optimized for speed.</li>
           <li>Smaller XML files.</li>
           <li>Easier to post-process.</li>
           <li>XML Schema is available.</li>
           <li>
             Recommended for use cases where documents are formatted concurrently and later
             concatenated to a single print job.
           </li>
         </ul>
       </section>
       <p>
         More technical information about the two formats can be found on the
         <a href="http://wiki.apache.org/xmlgraphics-fop/AreaTreeIntermediateXml/NewDesign">FOP Wiki</a>.
       </p>
     </section>
     <section id="architecture">
       <title>Architectural Overview</title>
       <figure src="images/if-architecture-overview.png"
         alt="Diagram with an architectural overview over the intermediate formats"/>
     </section>
     <section id="usage">
       <title>Usage of the Area Tree XML format (AT XML)</title>
       <p>
         As already mentioned, the area tree XML format is generated by using the
         <strong>XMLRenderer</strong> (MIME type: <strong>application/X-fop-areatree</strong>).
         So, you basically set the right MIME type for the output format and process your FO files
         as if you would create a PDF file.
       </p>
       <p>
         However, there is an important detail to consider: The
         various Renderers don't all use the same font sources. To be able to create the right
         area tree for the ultimate output format, you need to create the area tree XML file using
         the right font setup. This is achieved by telling the XMLRenderer to mimic another
         renderer. This is done by calling the XMLRenderer's mimicRenderer() method with an
         instance of the ultimate target renderer as the single parameter. This has a consequence:
         An area tree XML file rendered with the Java2DRenderer may not look as expected when it
         was actually generated for the PDF renderer. For renderers that use the same font setup,
         this restriction does not apply (PDF and PS, for example). Generating the area tree XML
         format file is the first step.
       </p>
       <p>
         The second step is to reparse the file using the <strong>AreaTreeParser</strong> which is
         found in the org.apache.fop.area package. The pages retrieved from the area tree XML file
         are added to an AreaTreeModel instance from where they are normally rendered using one of
         the available Renderer implementations. You can find examples for the area tree XML
         processing in the
         <a href="http://svn.apache.org/viewvc/xmlgraphics/fop/trunk/examples/embedding/java/embedding/intermediate/"><code>examples/embedding</code></a>
         directory in the FOP distribution.
       </p>
       <p>
         The basic pattern to parse the area tree XML format looks like this:
       </p>
       <source><![CDATA[
 FopFactory fopFactory = FopFactory.newInstance();

 // Setup output
 OutputStream out = new java.io.FileOutputStream(pdffile);
 out = new java.io.BufferedOutputStream(out);
 try {
     //Setup fonts and user agent
     FontInfo fontInfo = new FontInfo();
     FOUserAgent userAgent = fopFactory.newFOUserAgent();

     //Construct the AreaTreeModel that will received the individual pages
     AreaTreeModel treeModel = new RenderPagesModel(userAgent,
             MimeConstants.MIME_PDF, fontInfo, out);

     //Parse the area tree file into the area tree
     AreaTreeParser parser = new AreaTreeParser();
     Source src = new StreamSource(myIFFile);
     parser.parse(src, treeModel, userAgent);

     //Signal the end of the processing. The renderer can finalize the target document.
     treeModel.endDocument();
 } finally {
     out.close();
 }]]></source>
       <p>
         This example simply reads an area tree file and renders it to a PDF file. Please note, that in normal
         FOP operation you're shielded from having to instantiate the FontInfo object yourself. This
         is normally a task of the AreaTreeHandler which is not present in this scenario. The same
         applies to the AreaTreeModel instance, in this case an instance of a subclass called
         RenderPagesModel. RenderPagesModel is ideal in this case as it has very little overhead
         processing the individual pages. An important line in the example is the call to
         <code>endDocument()</code> on the AreaTreeModel. This lets the Renderer know that the processing
         is now finished.
       </p>
       <p>
         The area tree XML format can also be used from the <a href="running.html#standalone-start">command-line</a>
         by using the "-atin" parameter for specifying the area tree XML as input file. You can also
         specify a "mimic renderer" by inserting a MIME type between "-at" and the output file.
       </p>
       <section id="concat">
         <title>Concatenating Documents</title>
         <p>
           This initial example is obviously not very useful. It would be faster to create the PDF file
           directly. As the <a href="http://svn.apache.org/repos/asf/xmlgraphics/fop/trunk/examples/embedding/java/embedding/atxml/ExampleConcat.java">ExampleConcat.java</a>
           example shows you can easily parse multiple area tree files in a row and add the parsed pages to the
           same AreaTreeModel instance which essentially concatenates all the input document to one single
           output document.
         </p>
       </section>
       <section id="modifying">
         <title>Modifying Documents</title>
         <p>
           One of the most important use cases for this format is obviously modifying the area
           tree XML before finally rendering it to the target format. You can easily use XSLT to process
           the AT XML file according to your needs. Please note, that we will currently not formally describe
           the area tree XML format. You need to have a good understanding its structure so you don't
           create any non-parseable files. We may add an XML Schema and more detailed documentation at a
           later time. You're invited to help us with that.
         </p>
         <note>
           The area tree XML format is sensitive to changes in whitespace. If you're not careful,
           the modified file may not render correctly.
         </note>
       </section>
       <section id="advanced">
         <title>Advanced Use</title>
         <p>
           The generation of the area tree format as well as it parsing process has been designed to allow
           for maximum flexibility and optimization. Please note that you can call <code>setTransformerHandler()</code> on
           XMLRenderer to give the XMLRenderer your own TransformerHandler instance in case you would like to
           do custom serialization (to a W3C DOM, for example) and/or to directly modify the area tree using
           XSLT. The AreaTreeParser on the other side allows you to retrieve a ContentHandler instance where
           you can manually send SAX events to to start the parsing process (see <code>getContentHandler()</code>).
         </p>
       </section>
     </section>
     <section id="usage-if">
       <title>Usage of the Intermediate Format (IF)</title>
       <p>
         The Intermediate Format (IF) is generated by the <strong>IFSerializer</strong>
         (MIME type: <strong>application/X-fop-intermediate-format</strong>).
         So, you basically set the right MIME type for the output format and process your FO files
         as if you would create a PDF file.
       </p>
       <p>
         The IFSerializer is an implementation of the <strong>IFDocumentHandler</strong> and
         <strong>IFPainter</strong> interfaces. The <strong>IFRenderer</strong> class is responsible
         for converting FOP's area tree into calls against these two interfaces.
       </p>
       <ul>
         <li>
           IFDocumentHandler: This interface is used on the document-level and defines the
           overall structure of the Intermediate Format.
         </li>
         <li>
           IFPainter: This interface is used to generate graphical page content like text, images
           and borders.
         </li>
       </ul>
       <p>
         As with the AT XML, there is an important detail to consider: The various output
         implementations don't all use the same font sources. To be able
         to create the right IF for the ultimate output file, you need to create the IF file using
         the right font setup. This is achieved by telling the IFRenderer (responsible for
         converting the area tree into calls to the IFDocumentHandler and IFPainter interfaces)
         to mimic another renderer. This is done by calling the IFSerializer's
         mimicDocumentHandler() method with an instance of the ultimate target document handler
         as the single parameter. This has a consequence: An IF file rendered with the
         Java2DDocumentHandler may not look as expected when it was actually generated for the PDF
         implementation. For implementations that use the same font setup,
         this restriction does not apply (PDF and PS, for example). Generating the Intermediate
         Format file is the first step.
       </p>
       <p>
         The second step is to reparse the file using the <strong>IFParser</strong> which is
         found in the org.apache.fop.render.intermediate package. The IFParser simply takes an
         IFDocumentHandler instance against which it generates the appropriate calls. The IFParser
         is implemented as a SAX ContentHandler so you're free to choose the method for
         post-processing the IF file(s). You can use XSLT or write SAX- or DOM-based code to
         manipulate the contents. You can find examples for the Intermediate Format
         processing in the
         <a href="http://svn.apache.org/viewvc/xmlgraphics/fop/trunk/examples/embedding/java/embedding/intermediate/"><code>examples/embedding</code></a>
         directory in the FOP distribution.
       </p>
       <p>
         The basic pattern to parse the intermediate format looks like this:
       </p>
       <source><![CDATA[
 FopFactory fopFactory = FopFactory.newInstance();

 // Setup output
 OutputStream out = new java.io.FileOutputStream(pdffile);
 out = new java.io.BufferedOutputStream(out);
 try {
     //Setup user agent
     FOUserAgent userAgent = fopFactory.newFOUserAgent();

     //Create IFDocumentHandler instance
     IFDocumentHandler targetHandler;
     String mime = MimeConstants.MIME_PDF;
     targetHandler = fopFactory.getRendererFactory().createDocumentHandler(
             userAgent, mime);

     //Setup fonts
     IFUtil.setupFonts(targetHandler);

     //Tell the target handler where to write the PDF to
     targetHandler.setResult(new StreamResult(pdffile));

     //Parse the IF file
     IFParser parser = new IFParser();
     Source src = new StreamSource(myIFFile);
     parser.parse(src, targetHandler, userAgent);

 } finally {
     out.close();
 }]]></source>
       <p>
         This example simply reads an intermediate file and renders it to a PDF file. Here
         IFParser.parse() is used, but you can also just get a SAX ContentHandler by using the
         IFParser.getContentHandler() method.
       </p>
       <section id="concat-if">
         <title>Concatenating Documents</title>
         <p>
           This initial example is obviously not very useful. It would be faster to create the PDF file
           directly (without the intermediate step). As the
           <a href="http://svn.apache.org/repos/asf/xmlgraphics/fop/trunk/examples/embedding/java/embedding/intermediate/ExampleConcat.java">ExampleConcat.java</a>
           example shows you can easily parse multiple intermediate files in a row and use the
           IFConcatenator class to concatenate page sequences from multiple source files to a single
           output file. This particular example does the concatenation on the level of the
           IFDocumentHandler interface. You could also do this in XSLT or using SAX on the XML level.
           Whatever suits your process best.
         </p>
       </section>
       <section id="modifying-if">
         <title>Modifying Documents</title>
         <p>
           One of the most important use cases for this format is obviously modifying the
           intermediate format before finally rendering it to the target format. You can easily use
           XSLT to process the IF file according to your needs.
         </p>
         <p>
           There is an XML Schema (located under
           <a href="http://svn.apache.org/viewvc/xmlgraphics/fop/trunk/src/documentation/intermediate-format-ng/">src/documentation/intermediate-format-ng</a>)
           that helps you verify that your modified content is correct.
         </p>
         <p>
           For certain output formats there's a caveat: Formats like AFP and PCL do not support
           arbitrary transformations on the IF's "viewport" and "g" elements. Possible are
           only rotations in 90 degree steps and translations.
         </p>
       </section>
       <section id="advanced-if">
         <title>Advanced Use</title>
         <p>
           The generation of the intermediate format as well as it parsing process has been
           designed to allow for maximum flexibility and optimization. So rather than just passing
           in a StreamResult to IFSerializer's setResult() method, you can also use a SAXResult
           or a DOMResult. And as you've already seen , the IFParser on the other side allows you
           to retrieve a ContentHandler instance where you can manually send SAX events to
           start the parsing process (see <code>getContentHandler()</code>).
         </p>
       </section>
     </section>
   </body>
 </document>
	<?xml version="1.0" encoding="UTF-8"?>
	<!--
	Licensed to the Apache Software Foundation (ASF) under one or more
	contributor license agreements. See the NOTICE file distributed with
	this work for additional information regarding copyright ownership.
	The ASF licenses this file to You 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.
	-->
	<!-- $Id$ -->
	<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "http://forrest.apache.org/dtd/document-v20.dtd">
	<document>
	<header>
	<title>Apache™ FOP: Intermediate Format</title>
	<version>$Revision$</version>
	</header>
	<body>
	<note>
	Please note that the intermediate formats described here are
	<strong>advanced features</strong> and can be ignored by most users of Apache FOP.
	</note>
	<section id="introduction">
	<title>Introduction</title>
	<p>
	Apache™ FOP now provides two different so-called intermediate formats. The first one
	(let's call it the area tree XML format) is basically a 1:1 XML representation of FOP's
	area tree as generated by the layout engine. The area tree is conceptually defined in the
	<a href="http://www.w3.org/TR/2001/REC-xsl-20011015/slice1.html#section-N742-Formatting">XSL-FO specification in chapter 1.1.2</a>.
	Even though the area tree is mentioned in the XSL-FO specification, this part is not
	standardized. Therefore, the area tree XML format is a FOP-proprietary XML file format.
	The area tree XML can be generated through the area tree XML Renderer (the XMLRenderer).
	</p>
	<p>
	The second intermediate format (which we shall name exactly like this: the intermediate
	format)
	is a recent addition which tries to meet a slightly different set of goals. It is highly
	optimized for speed.
	</p>
	<p>
	The intermediate format can be used to generate intermediate documents that are modified
	before they are finally rendered to their ultimate output format. Modifications include
	adjusting and changing trait values, adding or modifying area objects, inserting prefabricated
	pages, overlays, imposition (n-up, rotation, scaling etc.). Multiple IF files can be combined
	to a single output file.
	</p>
	</section>
	<section id="which-if">
	<title>Which Intermediate Format to choose?</title>
	<p>
	Both formats have their use cases, so the choice you will make will depend on your
	particular situation. Here is a list of strengths and use cases for both formats:
	</p>
	<section id="strengths-at">
	<title>Area Tree XML (AT XML)</title>
	<ul>
	<li>1:1 representation of FOP's area tree in XML.</li>
	<li>Contains more structure information than the new intermediate format.</li>
	<li>Used in FOP's layout engine test suite for regression testing.</li>
	</ul>
	</section>
	<section id="strengths-if">
	<title>Intermediate Format (IF)</title>
	<ul>
	<li>Highly optimized for speed.</li>
	<li>Smaller XML files.</li>
	<li>Easier to post-process.</li>
	<li>XML Schema is available.</li>
	<li>
	Recommended for use cases where documents are formatted concurrently and later
	concatenated to a single print job.
	</li>
	</ul>
	</section>
	<p>
	More technical information about the two formats can be found on the
	<a href="http://wiki.apache.org/xmlgraphics-fop/AreaTreeIntermediateXml/NewDesign">FOP Wiki</a>.
	</p>
	</section>
	<section id="architecture">
	<title>Architectural Overview</title>
	<figure src="images/if-architecture-overview.png"
	alt="Diagram with an architectural overview over the intermediate formats"/>
	</section>
	<section id="usage">
	<title>Usage of the Area Tree XML format (AT XML)</title>
	<p>
	As already mentioned, the area tree XML format is generated by using the
	<strong>XMLRenderer</strong> (MIME type: <strong>application/X-fop-areatree</strong>).
	So, you basically set the right MIME type for the output format and process your FO files
	as if you would create a PDF file.
	</p>
	<p>
	However, there is an important detail to consider: The
	various Renderers don't all use the same font sources. To be able to create the right
	area tree for the ultimate output format, you need to create the area tree XML file using
	the right font setup. This is achieved by telling the XMLRenderer to mimic another
	renderer. This is done by calling the XMLRenderer's mimicRenderer() method with an
	instance of the ultimate target renderer as the single parameter. This has a consequence:
	An area tree XML file rendered with the Java2DRenderer may not look as expected when it
	was actually generated for the PDF renderer. For renderers that use the same font setup,
	this restriction does not apply (PDF and PS, for example). Generating the area tree XML
	format file is the first step.
	</p>
	<p>
	The second step is to reparse the file using the <strong>AreaTreeParser</strong> which is
	found in the org.apache.fop.area package. The pages retrieved from the area tree XML file
	are added to an AreaTreeModel instance from where they are normally rendered using one of
	the available Renderer implementations. You can find examples for the area tree XML
	processing in the
	<a href="http://svn.apache.org/viewvc/xmlgraphics/fop/trunk/examples/embedding/java/embedding/intermediate/"><code>examples/embedding</code></a>
	directory in the FOP distribution.
	</p>
	<p>
	The basic pattern to parse the area tree XML format looks like this:
	</p>
	<source><![CDATA[
	FopFactory fopFactory = FopFactory.newInstance();

	// Setup output
	OutputStream out = new java.io.FileOutputStream(pdffile);
	out = new java.io.BufferedOutputStream(out);
	try {
	//Setup fonts and user agent
	FontInfo fontInfo = new FontInfo();
	FOUserAgent userAgent = fopFactory.newFOUserAgent();

	//Construct the AreaTreeModel that will received the individual pages
	AreaTreeModel treeModel = new RenderPagesModel(userAgent,
	MimeConstants.MIME_PDF, fontInfo, out);

	//Parse the area tree file into the area tree
	AreaTreeParser parser = new AreaTreeParser();
	Source src = new StreamSource(myIFFile);
	parser.parse(src, treeModel, userAgent);

	//Signal the end of the processing. The renderer can finalize the target document.
	treeModel.endDocument();
	} finally {
	out.close();
	}]]></source>
	<p>
	This example simply reads an area tree file and renders it to a PDF file. Please note, that in normal
	FOP operation you're shielded from having to instantiate the FontInfo object yourself. This
	is normally a task of the AreaTreeHandler which is not present in this scenario. The same
	applies to the AreaTreeModel instance, in this case an instance of a subclass called
	RenderPagesModel. RenderPagesModel is ideal in this case as it has very little overhead
	processing the individual pages. An important line in the example is the call to
	<code>endDocument()</code> on the AreaTreeModel. This lets the Renderer know that the processing
	is now finished.
	</p>
	<p>
	The area tree XML format can also be used from the <a href="running.html#standalone-start">command-line</a>
	by using the "-atin" parameter for specifying the area tree XML as input file. You can also
	specify a "mimic renderer" by inserting a MIME type between "-at" and the output file.
	</p>
	<section id="concat">
	<title>Concatenating Documents</title>
	<p>
	This initial example is obviously not very useful. It would be faster to create the PDF file
	directly. As the <a href="http://svn.apache.org/repos/asf/xmlgraphics/fop/trunk/examples/embedding/java/embedding/atxml/ExampleConcat.java">ExampleConcat.java</a>
	example shows you can easily parse multiple area tree files in a row and add the parsed pages to the
	same AreaTreeModel instance which essentially concatenates all the input document to one single
	output document.
	</p>
	</section>
	<section id="modifying">
	<title>Modifying Documents</title>
	<p>
	One of the most important use cases for this format is obviously modifying the area
	tree XML before finally rendering it to the target format. You can easily use XSLT to process
	the AT XML file according to your needs. Please note, that we will currently not formally describe
	the area tree XML format. You need to have a good understanding its structure so you don't
	create any non-parseable files. We may add an XML Schema and more detailed documentation at a
	later time. You're invited to help us with that.
	</p>
	<note>
	The area tree XML format is sensitive to changes in whitespace. If you're not careful,
	the modified file may not render correctly.
	</note>
	</section>
	<section id="advanced">
	<title>Advanced Use</title>
	<p>
	The generation of the area tree format as well as it parsing process has been designed to allow
	for maximum flexibility and optimization. Please note that you can call <code>setTransformerHandler()</code> on
	XMLRenderer to give the XMLRenderer your own TransformerHandler instance in case you would like to
	do custom serialization (to a W3C DOM, for example) and/or to directly modify the area tree using
	XSLT. The AreaTreeParser on the other side allows you to retrieve a ContentHandler instance where
	you can manually send SAX events to to start the parsing process (see <code>getContentHandler()</code>).
	</p>
	</section>
	</section>
	<section id="usage-if">
	<title>Usage of the Intermediate Format (IF)</title>
	<p>
	The Intermediate Format (IF) is generated by the <strong>IFSerializer</strong>
	(MIME type: <strong>application/X-fop-intermediate-format</strong>).
	So, you basically set the right MIME type for the output format and process your FO files
	as if you would create a PDF file.
	</p>
	<p>
	The IFSerializer is an implementation of the <strong>IFDocumentHandler</strong> and
	<strong>IFPainter</strong> interfaces. The <strong>IFRenderer</strong> class is responsible
	for converting FOP's area tree into calls against these two interfaces.
	</p>
	<ul>
	<li>
	IFDocumentHandler: This interface is used on the document-level and defines the
	overall structure of the Intermediate Format.
	</li>
	<li>
	IFPainter: This interface is used to generate graphical page content like text, images
	and borders.
	</li>
	</ul>
	<p>
	As with the AT XML, there is an important detail to consider: The various output
	implementations don't all use the same font sources. To be able
	to create the right IF for the ultimate output file, you need to create the IF file using
	the right font setup. This is achieved by telling the IFRenderer (responsible for
	converting the area tree into calls to the IFDocumentHandler and IFPainter interfaces)
	to mimic another renderer. This is done by calling the IFSerializer's
	mimicDocumentHandler() method with an instance of the ultimate target document handler
	as the single parameter. This has a consequence: An IF file rendered with the
	Java2DDocumentHandler may not look as expected when it was actually generated for the PDF
	implementation. For implementations that use the same font setup,
	this restriction does not apply (PDF and PS, for example). Generating the Intermediate
	Format file is the first step.
	</p>
	<p>
	The second step is to reparse the file using the <strong>IFParser</strong> which is
	found in the org.apache.fop.render.intermediate package. The IFParser simply takes an
	IFDocumentHandler instance against which it generates the appropriate calls. The IFParser
	is implemented as a SAX ContentHandler so you're free to choose the method for
	post-processing the IF file(s). You can use XSLT or write SAX- or DOM-based code to
	manipulate the contents. You can find examples for the Intermediate Format
	processing in the
	<a href="http://svn.apache.org/viewvc/xmlgraphics/fop/trunk/examples/embedding/java/embedding/intermediate/"><code>examples/embedding</code></a>
	directory in the FOP distribution.
	</p>
	<p>
	The basic pattern to parse the intermediate format looks like this:
	</p>
	<source><![CDATA[
	FopFactory fopFactory = FopFactory.newInstance();

	// Setup output
	OutputStream out = new java.io.FileOutputStream(pdffile);
	out = new java.io.BufferedOutputStream(out);
	try {
	//Setup user agent
	FOUserAgent userAgent = fopFactory.newFOUserAgent();

	//Create IFDocumentHandler instance
	IFDocumentHandler targetHandler;
	String mime = MimeConstants.MIME_PDF;
	targetHandler = fopFactory.getRendererFactory().createDocumentHandler(
	userAgent, mime);

	//Setup fonts
	IFUtil.setupFonts(targetHandler);

	//Tell the target handler where to write the PDF to
	targetHandler.setResult(new StreamResult(pdffile));

	//Parse the IF file
	IFParser parser = new IFParser();
	Source src = new StreamSource(myIFFile);
	parser.parse(src, targetHandler, userAgent);

	} finally {
	out.close();
	}]]></source>
	<p>
	This example simply reads an intermediate file and renders it to a PDF file. Here
	IFParser.parse() is used, but you can also just get a SAX ContentHandler by using the
	IFParser.getContentHandler() method.
	</p>
	<section id="concat-if">
	<title>Concatenating Documents</title>
	<p>
	This initial example is obviously not very useful. It would be faster to create the PDF file
	directly (without the intermediate step). As the
	<a href="http://svn.apache.org/repos/asf/xmlgraphics/fop/trunk/examples/embedding/java/embedding/intermediate/ExampleConcat.java">ExampleConcat.java</a>
	example shows you can easily parse multiple intermediate files in a row and use the
	IFConcatenator class to concatenate page sequences from multiple source files to a single
	output file. This particular example does the concatenation on the level of the
	IFDocumentHandler interface. You could also do this in XSLT or using SAX on the XML level.
	Whatever suits your process best.
	</p>
	</section>
	<section id="modifying-if">
	<title>Modifying Documents</title>
	<p>
	One of the most important use cases for this format is obviously modifying the
	intermediate format before finally rendering it to the target format. You can easily use
	XSLT to process the IF file according to your needs.
	</p>
	<p>
	There is an XML Schema (located under
	<a href="http://svn.apache.org/viewvc/xmlgraphics/fop/trunk/src/documentation/intermediate-format-ng/">src/documentation/intermediate-format-ng</a>)
	that helps you verify that your modified content is correct.
	</p>
	<p>
	For certain output formats there's a caveat: Formats like AFP and PCL do not support
	arbitrary transformations on the IF's "viewport" and "g" elements. Possible are
	only rotations in 90 degree steps and translations.
	</p>
	</section>
	<section id="advanced-if">
	<title>Advanced Use</title>
	<p>
	The generation of the intermediate format as well as it parsing process has been
	designed to allow for maximum flexibility and optimization. So rather than just passing
	in a StreamResult to IFSerializer's setResult() method, you can also use a SAXResult
	or a DOMResult. And as you've already seen , the IFParser on the other side allows you
	to retrieve a ContentHandler instance where you can manually send SAX events to
	start the parsing process (see <code>getContentHandler()</code>).
	</p>
	</section>
	</section>
	</body>
	</document>