package VCP::Filter ;

=head1 NAME

VCP::Filter - A base class for filters

=head1 SYNOPSIS

   use VCP::Filter;
   @ISA = qw( VCP::Filter );
   ...

=head1 DESCRIPTION

A VPC::Filter is a VCP::Plugin that is placed between the source
and the destination and allows the stream of revisions to be altered.

For instance, the Map: option in vcp files is implemented by
VCP::Filter::Map

By default a filter is a pass-through.

=cut

$VERSION = 0.1 ;

use strict ;

use base "VCP::Plugin";
use fields (
    'DEST',   ## Points to the next filter.
);

sub dest {
   my VCP::Filter $self = shift;

   $self->{DEST} = shift if @_;
   return $self->{DEST};
}

###############################################################################

=head1 SUBCLASSING

This class uses the fields pragma, so you'll need to use base and 
possibly fields in any subclasses.

=over

=item last_rev_in_filebranch

(passthru; see L<VCP::Dest|VCP::Dest>)

=cut

sub last_rev_in_filebranch {
   shift->dest->last_rev_in_filebranch( @_ );
}

=item metadata_only

(passthru; see L<VCP::Dest|VCP::Dest>)

=cut

sub metadata_only {
   shift->dest->metadata_only( @_ );
}

=item sort_revs

(passthru)

=cut

sub sort_revs {
   shift->dest->sort_revs( @_ );
}

=item handle_header

(passthru)

=cut

sub handle_header {
   shift->dest->handle_header( @_ );
}

=item handle_rev

(passthru)

=cut

sub handle_rev {
   shift->dest->handle_rev( @_ );
}

=item handle_footer

(passthru)

=cut

sub handle_footer {
   shift->dest->handle_footer( @_ );
}

=back

=head1 COPYRIGHT

Copyright 2000, Perforce Software, Inc.  All Rights Reserved.

This module and the VCP package are licensed according to the terms given in
the file LICENSE accompanying this distribution, a copy of which is included in
L<vcp>.

=head1 AUTHOR

Barrie Slaymaker <barries@slaysys.com>

=cut

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