xml::sax::parserfactory(3) [osx man page]
SAX::ParserFactory(3) User Contributed Perl Documentation 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 automatically choose which parser to use: o $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. o 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). o 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. o 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 v5.16.2 2009-10-10 SAX::ParserFactory(3)
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SAX(3) User Contributed Perl Documentation SAX(3) 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: o 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. o 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; $script .= <<"INSTALL"; install_sax_driver : @$(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. o 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 perl v5.18.2 2011-09-04 SAX(3)