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<!-- $Id: upgrading.xml 1298724 2012-03-09 07:55:31Z cbowditch $ -->
<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "http://forrest.apache.org/dtd/document-v20.dtd">
<document>
  <header>
    <title>Upgrading from an Earlier Version of Apache™ FOP</title>
    <version>$Revision: 1298724 $</version>
  </header>
  <body>
    <section id="important">
      <title>Important!</title>
      <p>
        If you're planning to upgrade to the latest Apache™ FOP version there are a few very important things
        to consider:
      </p>
      <ul>
        <li>
          More than half of the codebase has been rewritten over the
          last four years. With version 0.93 the code has reached
          <strong>production level</strong>, and continues to improve with
          version 0.94 and 0.95.
        </li>
        <li>
          The API of FOP has changed considerably and is not
          backwards-compatible with versions 0.20.5 and
          0.91beta. Version 0.92 introduced the <strong>new stable
          API</strong>.
        </li>
        <li>
          Since version 0.92 some deprecated methods which were part
          of the old API have been removed. If you upgrade from 0.91
          beta, you will need to adjust your Java code. Similarly if
          you upgrade from 0.92 and use deprecated methods.
        </li>
        <li>
          If you are using a configuration file for version 0.20.5, you have to rebuild it in the new format. The format
          of the configuration files has changed since version 0.20.5. See conf/fop.xconf for
          an example configuration file. A XML Schema file can be found under
          src/foschema/fop-configuration.xsd.
        </li>
        <li>
          Beginning with version 0.94 you can skip the generation of
          font metric files and remove the "font-metrics" attribute
          in the font configuration. The font metrics files are, for
          the moment, still required if you use a TrueType Collection (*.ttc)
          and in that case you need to regenerate the font metrics file
          if yours are from a FOP version before 0.93.
        </li>
        <li>
          <p>
            The new code is much more strict about the interpretation of the XSL-FO 1.1 specification.
            Things that worked fine in version 0.20.5 might start to produce warnings or even errors
            now. FOP 0.20.5 contains many bugs which have been corrected in the new code.
          </p>
          <note label="An example">
            While FOP 0.20.5 allowed you to have empty <code>fo:table-cell</code> elements, the new code
            will complain about that (unless relaxed validation is enabled) because the specification
            demands at least one block-level element (<code>(%block;)+</code>, see
            <a href="http://www.w3.org/TR/xsl/#fo_table-cell">XSL-FO 1.1, 6.7.10</a>)
            inside an <code>fo:table-cell</code> element.
          </note>
        </li>
        <li>
          Extensions and Renderers written for version 0.20.5 will not work with the new code! The new FOP
          extension for <a href="http://barcode4j.sourceforge.net">Barcode4J</a> is available since
          January 2007.
        </li>
        <li>
          The SVG Renderer and the MIF Handler have not been resurrected, yet! They are currently non-functional
          and hope for someone to step up and reimplement them.
        </li>
      </ul>
    </section>
    <section id="issues">
      <title>What you need to know when you upgrade!</title>
      <p>
        When you use your existing FO files or XML/XSL files which work fine with FOP version
        0.20.5 against this FOP version some things may not work as expected. The following
        list will hopefully help you to identify and correct those problems. This does not mean
        that the new FOP is at fault. Quite the opposite actually! See below:
      </p>
      <ul>
        <li>
          Check the <a href="../compliance.html">Compliance page</a> for the feature causing
          trouble. It may contain the necessary information to understand and resolve the problem.
        </li>
        <li>
          As stated above empty table cells <code>&lt;fo:table-cell&gt;&lt;/fo:table-cell&gt;</code>
          are not allowed by the specification. The same applies to empty <code>static-content</code>
          and <code>block-container</code> elements, for example.
        </li>
        <li>
          0.20.5 is not XSL-FO compliant with respect to sizing images (<code>external-graphic</code>)
          or <code>instream-foreign-object</code>
          objects. If images or SVGs are sized differently in your outputs with the new FOP version
          check <a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=37136">Bug 37136</a>
          as it contains some hints on what to do. The file
          <a href="http://svn.apache.org/viewcvs.cgi/xmlgraphics/fop/trunk/examples/fo/basic/images.fo?view=markup">
          <code>"examples/fo/basic/images.fo"</code></a> has
          a number of good examples that show the new, more correct behaviour.
        </li>
        <li>
          The <code>fox:outline</code> extension is not implemented in this version anymore.
          It has been superseded by the new bookmark elements from XSL-FO 1.1. So please
          update your stylesheets accordingly.
        </li>
      </ul>
    </section>
  </body>
</document>