NAME¶
XML::SAX - Simple API for XML
SYNOPSIS¶
use XML::SAX;
# get a list of known parsers
my $parsers = XML::SAX->parsers();
# add/update a parser
XML::SAX->add_parser(q(XML::SAX::PurePerl));
# remove parser
XML::SAX->remove_parser(q(XML::SAX::Foodelberry));
# save parsers
XML::SAX->save_parsers();
DESCRIPTION¶
XML::SAX is a SAX parser access API for Perl. It includes classes and APIs
required for implementing SAX drivers, along with a factory class for
returning any SAX parser installed on the user's system.
USING A SAX2 PARSER¶
The factory class is XML::SAX::ParserFactory. Please see the documentation of
that module for how to instantiate a SAX parser: XML::SAX::ParserFactory.
However if you don't want to load up another manual page, here's a short
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);
This will automatically load a SAX2 parser (defaulting to XML::SAX::PurePerl if
no others are found) and return it to you.
In order to learn how to use SAX to parse XML, you will need to read
XML::SAX::Intro and for reference, XML::SAX::Specification.
WRITING A SAX2 PARSER¶
The first thing to remember in writing a SAX2 parser is to subclass
XML::SAX::Base. This will make your life infinitely easier, by providing a
number of methods automagically for you. See XML::SAX::Base for more details.
When writing a SAX2 parser that is compatible with XML::SAX, you need to inform
XML::SAX of the presence of that driver when you install it. In order to do
that, XML::SAX contains methods for saving the fact that the parser exists on
your system to a "INI" file, which is then loaded to determine which
parsers are installed.
The best way to do this is to follow these rules:
- •
- Add XML::SAX as a prerequisite in Makefile.PL:
WriteMakefile(
...
PREREQ_PM => { 'XML::SAX' => 0 },
...
);
Alternatively you may wish to check for it in other ways that will cause
more than just a warning.
- •
- Add the following code snippet to your Makefile.PL:
sub MY::install {
package MY;
my $script = shift->SUPER::install(@_);
if (ExtUtils::MakeMaker::prompt(
"Do you want to modify ParserDetails.ini?", 'Y')
=~ /^y/i) {
$script =~ s/install :: (.*)$/install :: $1 install_sax_driver/m;
$script .= <<"INSTALL";
install_sax_driver :
\t\@\$(PERL) -MXML::SAX -e "XML::SAX->add_parser(q(\$(NAME)))->save_parsers()"
INSTALL
}
return $script;
}
Note that you should check the output of this - \$(NAME) will use the name
of your distribution, which may not be exactly what you want. For example
XML::LibXML has a driver called XML::LibXML::SAX::Generator, which is used
in place of \$(NAME) in the above.
- •
- Add an XML::SAX test:
A test file should be added to your t/ directory containing something like
the following:
use Test;
BEGIN { plan tests => 3 }
use XML::SAX;
use XML::SAX::PurePerl::DebugHandler;
XML::SAX->add_parser(q(XML::SAX::MyDriver));
local $XML::SAX::ParserPackage = 'XML::SAX::MyDriver';
eval {
my $handler = XML::SAX::PurePerl::DebugHandler->new();
ok($handler);
my $parser = XML::SAX::ParserFactory->parser(Handler => $handler);
ok($parser);
ok($parser->isa('XML::SAX::MyDriver');
$parser->parse_string("<tag/>");
ok($handler->{seen}{start_element});
};
EXPORTS¶
By default, XML::SAX exports nothing into the caller's namespace. However you
can request the symbols "Namespaces" and "Validation"
which are the URIs for those features, allowing an easier way to request those
features via ParserFactory:
use XML::SAX qw(Namespaces Validation);
my $factory = XML::SAX::ParserFactory->new();
$factory->require_feature(Namespaces);
$factory->require_feature(Validation);
my $parser = $factory->parser();
AUTHOR¶
Current maintainer: Grant McLean, grantm@cpan.org
Originally written by:
Matt Sergeant, matt@sergeant.org
Kip Hampton, khampton@totalcinema.com
Robin Berjon, robin@knowscape.com
LICENSE¶
This is free software, you may use it and distribute it under the same terms as
Perl itself.
SEE ALSO¶
XML::SAX::Base for writing SAX Filters and Parsers
XML::SAX::PurePerl for an XML parser written in 100% pure perl.
XML::SAX::Exception for details on exception handling