XML::LibXML

Introduction
This module implements a Perl interface to the Gnome libxml2 library which provides interfaces for parsing and manipulating XML files. This module allows Perl programmers to make use of the highly capable validating XML parser and the high performance DOM implementation.

Important Notes
XML::LibXML was almost entirely reimplemented between version 1.40 to version 1.49. This may cause problems on some production machines. With version 1.50 a lot of compatibility fixes were applied, so programs written for XML::LibXML 1.40 or less should run with version 1.50 again.
In 1.59, a new callback API was introduced. This new API is not compatible with the previous one. See XML::LibXML::InputCallback manual page for details.
In 1.61 the XML::LibXML::XPathContext module, previously distributed separately, was merged in.
An experimental support for Perl threads introduced in 1.66 has been replaced in 1.67.

Dependencies
Prior to installation you MUST have installed the libxml2 library. You can get the latest libxml2 version from
http://xmlsoft.org/
Without libxml2 installed this module will neither build nor run.
Also XML::LibXML requires the following packages:
XML::SAX - base class for SAX parsers
XML::NamespaceSupport - namespace support for SAX parsers
These packages are required. If one is missing some tests will fail.
Again, libxml2 is required to make XML::LibXML work. The library is not just required to build XML::LibXML, it has to be accessible during run-time as well. Because of this you need to make sure libxml2 is installed properly. To test this, run the xmllint program on your system. xmllint is shipped with libxml2 and therefore should be available. For building the module you will also need the header file for libxml2, which in binary (.rpm,.deb) etc. distributions usually dwell in a package named libxml2-devel or similar.

Installation
(These instructions are for UNIX and GNU/Linux systems. For MSWin32, See Notes for Microsoft Windows below.)
To install XML::LibXML just follow the standard installation routine for Perl modules:
perl Makefile.PL
make
make test
make install # as superuser
Note that XML::LibXML is an XS based Perl extension and you need a C compiler to build it.
Note also that you should rebuild XML::LibXML if you upgrade libxml2 in order to avoid problems with possible binary incompatibilities between releases of the library.

Notes on libxml2 versions
XML::LibXML requires at least libxml2 2.6.16 to compile and pass all tests and at least 2.6.21 is required for XML::LibXML::Reader. For some older OS versions this means that an update of the pre-built packages is required.
Although libxml2 claims binary compatibility between its patch levels, it is a good idea to recompile XML::LibXML and run its tests after an upgrade of libxml2.
If your libxml2 installation is not within your $PATH, you can pass the XMLPREFIX=$YOURLIBXMLPREFIX parameter to Makefile.PL determining the correct libxml2 version in use. e.g.

 perl Makefile.PL XMLPREFIX=/usr/brand-new

will ask '/usr/brand-new/bin/xml2-config' about your real libxml2 configuration.
Try to avoid setting INC and LIBS directly on the command-line, for if used, Makefile.PL does not check the libxml2 version for compatibility with XML::LibXML.

Which version of libxml2 should be used?
XML::LibXML is tested against a couple versions of libxml2 before it is released. Thus there are versions of libxml2 that are known not to work properly with XML::LibXML. The Makefile.PL keeps a blacklist of the incompatible libxml2 versions.
If Makefile.PL detects one of the incompatible versions, it notifies the user. It may still happen that XML::LibXML builds and pass its tests with such a version, but that does not mean everything is OK. There will be no support at all for blacklisted versions!
As of XML::LibXML 1.61, only versions 2.6.16 and higher are supported. XML::LibXML will probably not compile with earlier libxml2 versions than 2.5.6. Versions prior to 2.6.8 are known to be broken for various reasons, versions prior to 2.1.16 exhibit problems with namespaced attributes and do not therefore pass XML::LibXML regression tests.
It may happen that an unsupported version of libxml2 passes all tests under certain conditions. This is no reason to assume that it shall work without problems. If Makefile.PL marks a version of libxml2 as incompatible or broken it is done for a good reason.

Notes for Microsoft Windows
Thanks to Randy Kobes there is a pre-compiled PPM package available on
http://theoryx5.uwinnipeg.ca/ppmpackages/
Usually it takes a little time to build the package for the latest release.
If you want to build XML::LibXML on Windows from source, you can use the following instructions contributed by Christopher J. Madsen:
These instructions assume that you already have your system set up to compile modules that use C components.
First, get the libxml2 binaries from http://xmlsoft.org/sources/win32/ (currently also available at http://www.zlatkovic.com/pub/libxml/).
You need:

  iconv-VERSION.win32.zip
  libxml2-VERSION.win32.zip
  zlib-VERSION.win32.zip

Download the latest version of each. (Each package will probably have a different version.) When you extract them, you'll get directories named iconv-VERSION.win32, libxml2-VERSION.win32, and zlib-VERSION.win32, each containing bin, lib, and include directories.
Combine all the bin, include, and lib directories under c:\Prog\LibXML. (You can use any directory you prefer; just adjust the instructions accordingly.)
Get the latest version of XML-LibXML from CPAN. Extract it.
Issue these commands in the XML-LibXML-VERSION directory:

  perl Makefile.PL INC=-Ic:\Prog\LibXML\include LIBS=-Lc:\Prog\LibXML\lib
  nmake
  copy c:\Prog\LibXML\bin\*.dll blib\arch\auto\XML\LibXML
  nmake test
  nmake install

(Note: Some systems use dmake instead of nmake.)
By copying the libxml2 DLLs to the arch directory, you help avoid conflicts with other programs you may have installed that use other (possibly incompatible) versions of those DLLs.

Notes for Mac OS X
Due refactoring the module, XML::LibXML will not run with some earlier versions of Mac OS X. It appears that this is related to special linker options for that OS prior to version 10.2.2. Since the developers do not have full access to this OS, help/ patches from OS X gurus are highly appreciated.
It is confirmed that XML::LibXML builds and runs without problems since Mac OS X 10.2.6.

Notes for HPUX
XML::LibXML requires libxml2 2.6.16 or later. There may not exist a usable binary libxml2 package for HPUX and XML::LibXML. If HPUX cc does not compile libxml2 correctly, you will be forced to recompile perl with gcc (unless you have already done that).
Additionally I received the following Note from Rozi Kovesdi:

Here is my report if someone else runs into the same problem:

Finally I am done with installing all the libraries and XML Perl
modules

The combination that worked best for me was:
gcc
GNU make

Most importantly - before trying to install Perl modules that depend on
libxml2:

must set SHLIB_PATH  to include  the path to  libxml2 shared library

assuming that you used the default:

export  SHLIB=/usr/local/lib

also, make sure that the config  files have execute permission:

/usr/local/bin/xml2-config
/usr/local/bin/xslt-config

they did not have +x after they were installed by 'make install'
and it took me a while to realize that this was my problem

or one can use:

perl Makefile.PL LIBS='-L/path/to/lib' INC='-I/path/to/include'

Contact
For bug reports, please use the CPAN request tracker on http://rt.cpan.org/NoAuth/Bugs.html?Dist=XML-LibXML
For suggestions etc. you may contact the maintainer directly at "pajas at ufal dot mff dot cuni dot cz", but in general, it is recommended to use the mailing list given below.
For suggestions etc., and other issues related to XML::LibXML you may use the perl XML mailing list (perl-xml@listserv.ActiveState.com), where most XML-related Perl modules are discussed. In case of problems you should check the archives of that list first. Many problems are already discussed there. You can find the list's archives and subscription options at http://aspn.activestate.com/ASPN/Mail/Browse/Threaded/perl-xml

Package History
Version < 0.98 were maintained by Matt Sergeant
0.98 > Version > 1.49 were maintained by Matt Sergeant and Christian Glahn
Versions >= 1.49 are maintained by Christian Glahn
Versions > 1.56 are co-maintained by Petr Pajas
Versions >= 1.59 are provisionally maintained by Petr Pajas

Patches and Developer Version
As XML::LibXML is open source software, help and patches are appreciated. If you find a bug in the current release, make sure this bug still exists in the developer version of XML::LibXML. This version can be cloned from its Git repository. For more information about that, see:
https://github.com/shlomif/perl-XML-LibXML
Please consider all regression tests as correct. If any test fails it is most certainly related to a bug.
If you find documentation bugs, please fix them in the libxml.dbk file, stored in the docs directory.

Known Issues
The push-parser implementation causes memory leaks.