For generic questions about XSL stylesheets and transformations, use the XSL-List -- Open Forum on XSL hosted by Mulberry Technologies. There is an archive that can be searched as well. Specific questions about Xalan-C++ can be asked on the Xalan-dev list. Please review this document and the archives before posting new questions.
Xerces-C++ is a validating XML parser written in a portable subset of C++. Xerces-C++ makes it easy to give your application the ability to read and write XML data. Like Xalan-C++, Xerces-C++ is available from the Apache XML site: http://xml.apache.org/xerces-c/index.html
Which version of Xerces should I be using?
The Xalan-C++ release notes includes information about the Xerces-C++ release with which the Xalan-C++ release has been coordinated and tested. See Status
I have encountered problem executing the Xalan-C++ sample applications after rebuilding them under Win32 Environment (Windows NT 4.0, SP3).
When I tried to execute the sample, I receive the error message "Debug Assertion Failed! ... Expression: _BLOCK_TYPE_IS_VALID(pHead->nBlockUse)".
You may be mixing debug and release versions of executables and libraries. In other words, if you are compiling the sample for debug, then you should link with the debug version of the Xalan-C++ and Xerces-C++ libraries and run with the debug version of the dynamic link libraries.
What do I need to rebuild Xalan-C++ on Windows?
To build Xalan-C++ on Windows, you need Xerces-C++ and MS Visual C++ 6.0 installed with Service Pack 3 for Visual C++ and Visual Studio. You should also apply the bug fixes for the C++ standard library that shipped with Visual C++ 6.0. These fixes are available from the Dinkumware site: http://www.dinkumware.com/vc_fixes.html.
To build Xalan-C++ on supported UNIX platforms, you need Xerces-C++ and a supported C++ compilers (see the table below). If your compiler does not support the STL or its implementation is old, you must install the STLPort.
For more details see: http://xml.apache.org/xalan-c/readme.html#unix
The Standard Template Library, or STL, is a C++ library of container classes, algorithms, and iterators; it provides many of the basic computer science algorithms and data structures. Xalan-C++ implementation uses the SLT. STLport ports SGI STL to any platform possible and provides all necessary wrap-ups installed. If your compiler does not support the STL or its implementation is out of date, you will need to install the STLPort.
The International Components for Unicode(ICU) is a C and C++ library that provides robust and full-featured Unicode support on a wide variety of platforms. Xalan-C++ uses the ICU to extend support for encoding, number formatting, and sorting.
I am getting a tar checksum error on Solaris. What's the problem?
The Solaris tar utility you are using does not properly handle files with long pathnames.
You must use GNU tar (gtar), which handles arbitrarily long pathnames
and is freely available on every platform on which Xalan-C++ is
supported. If you don't already have GNU tar installed on your system,
you can obtain it from the Free Software Foundation
http://www.gnu.org/software/tar/tar.html. For additional
background information on this problem, see the online manual
GNU tar and POSIX tar for the utility.
Is it possible to run Xalan-C++ from an Apache server?
A simple Apache module called ApacheModuleXSLT is provided as a sample. It demonstrates how to integrate Xalan-C++ with Apache.
Is Xalan-C++ thread-safe?
In order to support very efficient use in multi-threaded applications, Xalan-C++ is designed to avoid synchronization as much as
possible. Each thread of execution is required to have its own set of "support" objects that contain the state of the
transformation. Accordingly, no synchronization is required when multiple threads are executing.
Parsed ("compiled") stylesheets (see Compiling stylesheets) and parsed
source documents may be freely shared by multiple threads of execution without worrying
about providing synchronized access to them. The only exception to this rule: You use XercesParserLiaison to parse a
document after calling XercesParserLiaison::setBuildBridgeNodes(false) or XercesParserLiaison::setThreadSafe(false). In this case,
the document cannot be shared by multiple threads of execution. For reasons of performance, we do not recommend the use of
XercesParserLiaison, so this should not be an issue for most applications.
All other objects in Xalan-C++ are not thread-safe. Each thread must have its own instance of each object.
See the ThreadSafe sample program for more information.
What can I do to speed up transformations?
To maximize performance, here are some suggestions for you to keep in mind as you set up your applications:
Use a compiled stylesheet when you expect to use the stylesheet more than once.
Set up your stylesheets to function efficiently.
Don't use "//" (descendant axes) patterns near the root of a large document.
Use xsl:key elements and the key() function as an efficient way to retrieve node sets.
Where possible, use pattern matching rather than xsl:if or xsl:when statements.
xsl:for-each is fast because it does not require pattern matching.
Keep in mind that xsl:sort prevents incremental processing.
When you create variables, <xsl:variable name="fooElem" select="foo"/> is usually faster than
<xsl:variable name="fooElem"><xsl:value-of-select="foo"/></xsl:variable>.
Be careful using the last() function.
The use of index predicates within match patterns can be expensive.
Can I validate an XSL stylesheet?
An XSL stylesheet is an XML document, so it can have a DOCTYPE and be subject to validation, but you probably will have
to write a custom DTD for the purpose.
The XSLT Recommendation includes a DTD Fragment
for XSL Stylesheets 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.
You can use the xsl:stylesheet doctype defined in xsl-html40s.dtd for stylesheets that generate HTML.