sax::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 application 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 applications 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 specifying the parser you want in
the call to "parser()", XML::SAX has several ways to auto
matically 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
contain 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/fea

tures/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/valida

tion' => 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 pack
age 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.

docs.sk