# XML::SAX::ParserFactory - Obtain a SAX parser - perldoc - [phpMan]

## NAME
    [XML::SAX::ParserFactory](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserFactory/markdown) - Obtain a SAX parser

## SYNOPSIS
      use [XML::SAX::ParserFactory](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserFactory/markdown);
      use [XML::SAX::XYZHandler](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AXYZHandler/markdown);
      my $handler = [XML::SAX::XYZHandler](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AXYZHandler/markdown)->new();
      my $p = [XML::SAX::ParserFactory](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserFactory/markdown)->parser(Handler => $handler);
      $p->parse_uri("foo.xml");
      # or $p->parse_string("<foo/>") or $p->parse_file($fh);

## DESCRIPTION
    [XML::SAX::ParserFactory](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserFactory/markdown) 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](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX/markdown), and then it will become available to all applications that
    use [XML::SAX::ParserFactory](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserFactory/markdown) to obtain a SAX parser.

    Unlike DBI however, XML/SAX parsers almost all work alike (especially if they subclass
    [XML::SAX::Base](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3ABase/markdown), as they should), so rather than specifying the parser you want in the call to
### parser

    *   $[XML::SAX::ParserPackage](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserPackage/markdown)

        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](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserPackage/markdown) = "[XML::SAX::Expat](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AExpat/markdown) (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](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserFactory/markdown);
          my $factory = [XML::SAX::ParserFactory](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserFactory/markdown)->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](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3AParserFactory/markdown)->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](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX/markdown) package ships with a pure perl XML parser, [XML::SAX::PurePerl](https://www.chedong.com/phpMan.php/perldoc/XML%3A%3ASAX%3A%3APurePerl/markdown), 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.