XML::Filter::SAXT

XML::Filter::SAXT(3)  User Contributed Perl Documentation XML::Filter::SAXT(3)



NAME
       XML::Filter::SAXT - Replicates SAX events to several SAX event handlers

SYNOPSIS
        $saxt = new XML::Filter::SAXT ( { Handler => $out1 },
                                        { DocumentHandler => $out2 },
                                        { DTDHandler => $out3,
                                          Handler => $out4
                                        }
                                      );

        $perlsax = new XML::Parser::PerlSAX ( Handler => $saxt );
        $perlsax->parse ( [OPTIONS] );

DESCRIPTION
       SAXT is like the Unix 'tee' command in that it multiplexes the input
       stream to several output streams. In this case, the input stream is a
       PerlSAX event producer (like XML::Parser::PerlSAX) and the output
       streams are PerlSAX handlers or filters.

       The SAXT constructor takes a list of hash references. Each hash speci-
       fies an output handler. The hash keys can be: DocumentHandler, DTDHan-
       dler, EntityResolver or Handler, where Handler is a combination of the
       previous three and acts as the default handler.  E.g. if Documen-
       tHandler is not specified, it will try to use Handler.

       EXAMPLE

       In this example we use XML::Parser::PerlSAX to parse an XML file and to
       invoke the PerlSAX callbacks of our SAXT object. The SAXT object then
       forwards the callbacks to XML::Checker, which will 'die' if it encoun-
       ters an error, and to XML::Hqandler::BuildDOM, which will store the XML
       in an XML::DOM::Document.

        use XML::Parser::PerlSAX;
        use XML::Filter::SAXT;
        use XML::Handler::BuildDOM;
        use XML::Checker;

        my $checker = new XML::Checker;
        my $builder = new XML::Handler::BuildDOM (KeepCDATA => 1);
        my $tee = new XML::Filter::SAXT ( { Handler => $checker },
                                          { Handler => $builder } );

        my $parser = new XML::Parser::PerlSAX (Handler => $tee);
        eval
        {
           # This is how you set the error handler for XML::Checker
           local $XML::Checker::FAIL = \&my_fail;

           my $dom_document = $parser->parsefile ("file.xml");
           ... your code here ...
        };
        if ($@)
        {
           # Either XML::Parser::PerlSAX threw an exception (bad XML)
           # or XML::Checker found an error and my_fail died.
           ... your error handling code here ...
        }

        # XML::Checker error handler
        sub my_fail
        {
          my $code = shift;
          die XML::Checker::error_string ($code, @_)
               if $code < 200;   # warnings and info messages are >= 200
        }

CAVEATS
       This is still alpha software.  Package names and interfaces are subject
       to change.

AUTHOR
       Send bug reports, hints, tips, suggestions to Enno Derksen at
       <enno@att.com>.



perl v5.8.0                       2000-02-11              XML::Filter::SAXT(3)