Provided by: libxml-sax-machines-perl_0.42-1_all bug

NAME

       XML::SAX::Tap - Tap a pipeline of SAX processors

SYNOPSIS

           use XML::SAX::Machines qw( Pipeline Tap ) ;

           my $m = Pipeline(
               "UpstreamFilter",
               Tap( "My::Reformatter", \*STDERR ),
               "DownstreamFilter",
           );

           my $m = Pipeline(
               "UpstreamFilter",
               Tap( "| xmllint --format -" ),
               "DownstreamFilter",
           );

DESCRIPTION

       XML::SAX::Tap is a SAX machine that passes each event it receives on to a brach handler
       and then on down to it's main handler.  This allows debugging output, logging output,
       validators, and other processors (and machines, of course) to be placed in a pipeline.
       This differs from XML::Filter::Tee, XML::Filter::SAXT and XML::SAX::Distributer in that a
       tap is also a pipeline; it contains the processoring that handles the tap.

       It's like XML::Filter::Tee in that the events are not buffered; each event is sent first
       to the tap, and then to the branch (this is different from XML::SAX::Dispatcher, which
       buffers the events).

       It's like XML::SAX::Pipeline in that it contains a series of processors in a pipeline;
       these comprise the "tapping" processors:

                   +----------------------------------------------+
                   |                  Tap instance                |
                   |                                              |
                   |  Intake                                      |
                   |  +-----+    +---------+        +---------+   |
        upstream --+->| Tee |--->| Stage_0 |--...-->| Stage_N |   |
                   |  +-----+    +---------+        +---------+   |
                   |         \                                    |
                   |          \                          Exhaust  |
                   |           +----------------------------------+--> downstream
                   |                                              |
                   +----------------------------------------------+

       The events are not copied, since they may be data structures that are difficult or
       impossibly to copy properly, like parts of a C-based DOM implementation.

       Events go to the tap first so that you can validate events using a tap that throws
       exceptions and they will be acted on before the tap's handler sees them.

       This machine has no "Exhaust" port (see XML::SAX::Machine for details about "Intake" and
       "Exhaust" ports).

METHODS

       new
               my $tap = XML::SAX::Tap->new( @tap_processors, \%options );

AUTHOR

           Barrie Slaymaker <barries@slaysys.com>

COPYRIGHT

           Copyright 2002, Barrie Slaymaker, All Rights Reserved

       You may use this module under the terms of the Artistic, GNU Public, or BSD licenses, as
       you choose.