XML::SAX::ParserFactory

SAX::ParserFactory(3)User Contributed Perl DocumentationSAX::ParserFactory(3)



NAME
       XML::SAX::ParserFactory - Obtain a SAX parser

SYNOPSIS
	 use XML::SAX::ParserFactory;
	 use XML::SAX::XYZHandler;
	 my $handler = XML::SAX::XYZHandler->new();
	 my $p = XML::SAX::ParserFactory->parser(Handler => $handler);
	 $p->parse_uri("foo.xml");
	 # or $p->parse_string("<foo/>") or $p->parse_file($fh);

DESCRIPTION
       XML::SAX::ParserFactory is a factory class for providing an applica-
       tion with a Perl SAX2 XML parser. It is akin to DBI - a front end for
       other parser classes. Each new SAX2 parser installed will register
       itself with XML::SAX, and then it will become available to all appli-
       cations that use XML::SAX::ParserFactory to obtain a SAX parser.

       Unlike DBI however, XML/SAX parsers almost all work alike (especially
       if they subclass XML::SAX::Base, as they should), so rather than spec-
       ifying the parser you want in the call to "parser()", XML::SAX has
       several ways to automatically choose which parser to use:

       * $XML::SAX::ParserPackage
	   If this package variable is set, then this package is "require()"d
	   and an instance of this package is returned by calling the "new()"
	   class method in that package. If it cannot be loaded or there is
	   an error, an exception will be thrown. The variable can also con-
	   tain a version number:

	     $XML::SAX::ParserPackage = "XML::SAX::Expat (0.72)";

	   And the number will be treated as a minimum version number.

       * Required features
	   It is possible to require features from the parsers. For example,
	   you may wish for a parser that supports validation via a DTD. To
	   do that, use the following code:

	     use XML::SAX::ParserFactory;
	     my $factory = XML::SAX::ParserFactory->new();
	     $factory->require_feature(’http://xml.org/sax/features/validation’);
	     my $parser = $factory->parser(...);

	   Alternatively, specify the required features in the call to the
	   ParserFactory constructor:

	     my $factory = XML::SAX::ParserFactory->new(
		     RequiredFeatures => {
			  ’http://xml.org/sax/features/validation’ => 1,
			  }
		     );

	   If the features you have asked for are unavailable (for example
	   the user might not have a validating parser installed), then an
	   exception will be thrown.

	   The list of known parsers is searched in reverse order, so it will
	   always return the last installed parser that supports all of your
	   requested features (Note: this is subject to change if someone
	   comes up with a better way of making this work).

       * SAX.ini
	   ParserFactory will search @INC for a file called SAX.ini, which is
	   in a simple format:

	     # a comment looks like this,
	     ; or like this, and are stripped anywhere in the file
	     key = value # SAX.in contains key/value pairs.

	   All whitespace is non-significant.

	   This file can contain either a line:

	     ParserPackage = MyParserModule (1.02)

	   Where MyParserModule is the module to load and use for the parser,
	   and the number in brackets is a minimum version to load.

	   Or you can list required features:

	     http://xml.org/sax/features/validation = 1

	   And each feature with a true value will be required.

       * Fallback
	   If none of the above works, the last parser installed on the
	   user’s system will be used. The XML::SAX package ships with a pure
	   perl XML parser, XML::SAX::PurePerl, so that there will always be
	   a fallback parser.

AUTHOR
       Matt Sergeant, matt@sergeant.org

LICENSE
       This is free software, you may use it and distribute it under the same
       terms as Perl itself.



perl v5.8.8			  2008-08-03		SAX::ParserFactory(3)