# XML::SAX::ParserFactory - phpMan

## 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:

    *   $[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/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.