NAME¶
XML::SAX::Tap - Tap a pipeline of SAX processors
VERSION¶
version 0.46
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).
NAME¶
XML::SAX::Tap - Tap a pipeline of SAX processors
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.
AUTHORS¶
- •
- Barry Slaymaker
- •
- Chris Prather <chris@prather.org>
COPYRIGHT AND LICENSE¶
This software is copyright (c) 2013 by Barry Slaymaker.
This is free software; you can redistribute it and/or modify it under the same
terms as the Perl 5 programming language system itself.