You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@xalan.apache.org by dl...@apache.org on 2001/01/23 23:07:21 UTC

cvs commit: xml-xalan/java/xdocs/sources/xalan faq.xml

dleslie     01/01/23 14:07:21

  Added:       java/xdocs/sources/xalan faq.xml
  Log:
  Added FAQs
  
  Revision  Changes    Path
  1.1                  xml-xalan/java/xdocs/sources/xalan/faq.xml
  
  Index: faq.xml
  ===================================================================
  <?xml version="1.0" standalone="no"?> 
  <!DOCTYPE faqs SYSTEM "../../style/dtd/faqs.dtd">
  
  <faqs title="Frequently asked questions">
  
    <faq title="Where do I go to learn about XSLT">  
      <q>Where do I go to learn about XSLT?</q>    
      <a><p>The definitive sources are the W3C XSLT and XPath recommendations: <resource-ref idref="xslt"/> and 
      <resource-ref idref="xpath"/>.</p>
      <p>For a brief listing of tutorials, discussion forums, and other materials, see <link idref="overview"
       anchor="uptospeed">Getting up to speed with XSLT</link>.</p></a>
    </faq>
  
    <faq title="Which version of Xerces should I be using?">  
      <q>Which version of Xerces should I be using?</q>    
      <a><p>&xslt4j-current; has been tested with &xml4j-used;. See <link idref="readme" anchor="status">Status</link></p></a>
    </faq>
    
    <faq title="Compatibility with &xslt4j; version 1">
     <q>How do I run applications that use the &xslt4j; version 1 API with &xslt4j2;</q>
     <a><p>Use the Xalan-Java 1 compatibility JAR to recompile and run your &xslt4j; 1 applications with &xslt4j2;. For more information, see 
     <link idref="usagepatterns" anchor="compat">Using the &xslt4j; version 1 API</link>.</p></a>
    </faq>
      
    <faq title="TrAX and JAXP">
      <q>What are TrAX and JAXP, and are they related?</q>
      <a><p>TrAX is the Transformation API for XML. In November 2000, TrAX was revised and incorporated into JAXP, the JAVA API for XML
      Processing. JAXP (including TrAX) provides users a standard, vendor-neutral API for working with (and transforming) XML documents. 
      You can use this API to build applications that are not bound to the particular implementation details of a given XML parser or XSL
      transformer.</p>
      <p>&xslt4j; includes the JAXP packages, implements the TrAX portion of that API (javax.xml.transform....), and includes xerces.jar from
      &xml4j;, which implements the parser portion of the API (javax.xml.parser....).</p>
  <p>For more information, see <resource-ref idref="trax"/> and <resource-ref idref="jaxp11"/>.</p></a>
    </faq>
    <faq title="Chaining transformations">  
      <q>How do you chain together a series of transformations?"</q>
      
      <a><p>&xslt4j; supports two strategies for chaining together a series of transformations such that the output of each 
      transformation provides input for the next transformation.</p>
      <ul>
        <li>For each transformation in the series, you can set one SAX ContentHandler to process the input, and another ContenHandler to process
         the output.<br/><br/></li>
        <li>You can also set up a series of parent-child relationships between an XMLReader and one or more XMLFilters.</li> 
      </ul>
      <p>For the details and links to examples, see <link idref="usagepatterns" anchor="outasin">Using transformation output as input for 
      another transformation</link>.</p></a>
    </faq>
    
   
    <faq title="Speeding up transformations">
    
      <q>What can I do to speed up transformations?</q>
      
      <a><p>In the ongoing development of &xslt4j;, enhancing performance is the primary goal of the &xslt4j; team.
      Here are some preliminary suggestions for you to keep in mind as you set up your applications:</p><ul>
      <li>Use a Templates object (with a different Transformers for each transformation) to perform multiple transformations with the same 
      set of stylesheet instructions (see <link idref="usagepatterns" anchor="multithreading">Multithreading</link>).<br/><br/></li>         
      <li>Set up your stylesheets to function efficiently.<br/><br/></li>
         <ul>
           <li>Don't use "//" (descendant axes) patterns near the root of a large document.<br/><br/></li>
           <li>Use xsl:key elements and the key() function as an efficient way to retrieve node sets.<br/><br/></li>
           <li>Where possible, use pattern matching rather than xsl:if or xsl:when statements.<br/><br/></li>
           <li>xsl:for-each is fast because it does not require pattern matching.<br/><br/></li>
           <li>Keep in mind that xsl:sort prevents incremental processing.<br/><br/></li>
           <li>When you create variables, &lt;xsl:variable name="fooElem" select="foo"/&gt; is usually faster than
           &gt;xsl:variable name="fooElem"&gt;&lt;xsl:value-of-select="foo"/&gt;&lt;/xsl:variable&gt;.<br/><br/></li>
           <li>Be careful using the last() function.<br/><br/></li>
           <li>The use of index predicates within match patterns can be expensive.<br/><br/></li>
           <li>Decoding and encoding is expensive.<br/><br/></li>
         </ul>
       <li>For the ultimate in server-side scalability, perform transform operations on the client. For examples, see 
       <link idref="samples" anchor="appletxmltohtml">appletXMLtoHTML</link> and <link idref="samples"
       anchor="get-todo-list">get-todo-list</link>.</li>
      </ul></a>
    </faq>
  
    <faq title="NoClassDefFound errors">
    
      <q>I'm getting a NoClassDefFound error. What has to be on the class path?</q>
      
      <a><ol>
      <li>xalan.jar and xerces.jar (or the XML parser you are using) must always be on the class path.<br/><br/></li>
      <li>To run the samples in the samples subdirectories, xalansamples.jar must be on the class path. To run the servlet (in
      samples/servlet), xalanservlet.jar must be on the classpath along with the javax.servlet and javax.servlet.http packages. Sun distributes
      the javax.servlet packages in the JSWDK servlet.jar file.<br/><br/></li>
      <li>To run extensions (including the samples in samples/extensions), bsf.jar, and bsfengines.jar must be on the 
      class path. To run extensions implemented in JavaScript, js.jar must also be on the class path. For information on what 
      you need to run extensions implemented in other scripting languages, see <link idref="extensions"
      anchor="supported-lang">Supported languages</link>.<br/><br/></li>
      <li>To run applications that use the &xslt4j; version 1 API, you must put xalanj1compat.jar on the classpath, recompile the application,
      and be sure xalanj1compat.jar is on the classpath at run time (see <link idref="usagepatterns" anchor="compat">Using the &xslt4j; version 1
      API)</link>.</li>
      </ol>
      <p>For more information, see <link idref="getstarted" anchor="classpath">Setting up the system class path</link>.</p></a>
     </faq>
   
  
  	<faq title="Stylesheet validation">
  		<q>How do I validate an XSL stylesheet?</q>
  		<a>
        <p>An XSL stylesheet is an XML document, so it can have a DOCTYPE and be subject to validation, right? </p>
        <p>The XSLT Recommendation includes a <jump href="http://www.w3.org/TR/xslt#dtd">DTD Fragment 
        for XSL Stylesheets</jump> with some indications of what you need to do to create a complete DTD for a given
        stylesheet. Keep in mind that stylesheets can include literal result elements and produce output that is not valid
        XML.</p>
        <p>You can use the xsl:stylesheet doctype defined in xsl-html40s.dtd for stylesheets that generate HTML.</p>
  		</a>
  	</faq> 
  </faqs>