---
name: "XML::Filter::Tee"
section: "3pm"
platform: "linux"
package: "libxml-sax-machines-perl"
version: "0.46-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/XML::Filter::Tee"
---

# XML::Filter::Tee(3pm)

Send SAX events to multiple processor, with switching

## NAME

XML::Filter::Tee - Send SAX events to multiple processor, with switching

## VERSION

version 0.46

## SYNOPSIS

```
    my $t = XML::Filter::Tee->new(
        { Handler => $h0 },
        { Handler => $h1 },
        { Handler => $h2 },
        ...
    );
    ## Altering the handlers list:
    $t->set_handlers( $h0, $h1, $h2, $h3 );
    ## Controlling flow to a handler by number and by reference:
    $t->disable_handler( 0 );
    $t->enable_handler( 0 );
    $t->disable_handler( $h0 );
    $t->enable_handler( $h0 );
    ## Use in a SAX machine (though see L<XML::SAX::Pipeline> and
    ## L<XML::SAX::Tap> for a more convenient way to build a machine
    ## like this):
    my $m = Machine(
        [ Intake => "XML::Filter::Tee" => qw( A B ) ],
        [ A      => ">>log.xml" ],
        [ B      => \*OUTPUT ],
    );
```

## DESCRIPTION

XML::Filter::Tee is a SAX filter that passes each event it receives on to a list of downstream handlers.

It's like XML::Filter::SAXT 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). Unlike XML::Filter::SAXT, it allows it's list of handlers to be reconfigured (via "set\_handlers") and it allows control over which handlers are allowed to receive events.  These features are designed to make XML::Filter::Tee instances more useful with SAX machines, but they to add some overhead relative to XML::Filter::SAXT.

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.  This means that the handlers must not alter the events or later handlers will see the alterations.

## NAME

XML::Filter::Tee - Send SAX events to multiple processor, with switching

## METHODS

- new

  ```
      my $t = XML::Filter::Tee->new(
          { Handler => $h0 },
          { Handler => $h1 },
          { Handler => $h2 },
          ...
      );
  ```

- set\_handlers

  ```
      $t->set_handlers( $h0, $h1, $h2 );
      $t->set_handlers( {
              Handler => $h0,
          },
          {
              Handler => $h1,
          },
      );
  ```

  Replaces the current list of handlers with new ones.

  Can also name handlers to make enabling/disabling them by name easier:

  ```
      $m->set_handlers( {
              Handler => $validator,
              Name    => "Validator",
          },
          {
              Handler => $outputer,
          },
      );
      $m->disable_handler( "Validator" );
  ```

- disable\_handler

  ```
      $t->disable_handler( 0 );            ## By location
      $t->disable_handler( "Validator" );  ## By name
      $t->disable_handler( $h0 );          ## By reference
  ```

  Stops sending events to the indicated handler.

- enable\_handler

  ```
      $t->enable_handler( 0 );            ## By location
      $t->enable_handler( "Validator" );  ## By name
      $t->enable_handler( $h0 );          ## By reference
  ```

  Stops sending events to the indicated handler.

## 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.