Courier::Filter::Logger - Abstract base class for loggers used by the

Courier-Filter documentation Contained in the Courier-Filter distribution.

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NAME

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Courier::Filter::Logger - Abstract base class for loggers used by the Courier::Filter framework

SYNOPSIS

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Courier::Filter logging

    use Courier::Filter::Logger::My;  # Need to use a non-abstract sub-class.

    my $logger = Courier::Filter::Logger::My->new(%options);

    # For use in an individual filter module:
    my $module = Courier::Filter::Module::My->new(
        ...
        logger => $logger,
        ...
    );

    # For use as a global Courier::Filter logger object:
    my $filter = Courier::Filter->new(
        ...
        logger => $logger,
        ...
    );

Deriving new logger classes

    package Courier::Filter::Logger::My;
    use base qw(Courier::Filter::Logger);

DESCRIPTION

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Sub-classes of Courier::Filter::Logger are used by the Courier::Filter mail filtering framework and its filter modules for the logging of errors and message rejections to arbitrary targets, like file handles or databases.

When overriding a method in a derived class, do not forget calling the inherited method from your overridden method.

Constructor

The following constructor is provided and may be overridden:

new(%options): returns Courier::Filter::Logger

Creates a new logger using the %options given as a list of key/value pairs. Initializes the logger, by creating/opening I/O handles, connecting to databases, etc..

Courier::Filter::Logger::new() creates a hash-ref as an object of the invoked class, and stores the %options in it, but does nothing else.

Destructor

The following destructor is provided and may be overridden:

destroy

Uninitializes the logger, by closing I/O handles, disconnecting from databases, etc..

Courier::Filter::Logger::destroy() does nothing. Sub-classes may override this method and define clean-up behavior.

Instance methods

The following instance methods are provided and may be overridden:

log_error($text)

Logs the error message given as $text (a string which may contain newlines).

Courier::Filter::Logger::log_error() does nothing and should be overridden.

log_rejected_message($message, $reason)

Logs the Courier::Message given as $message as having been rejected due to $reason (a string which may contain newlines).

Courier::Filter::Logger::log_rejected_message() does nothing and should be overridden.

SEE ALSO

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Courier::Filter, Courier::Filter::Module.

For a list of prepared loggers that come with Courier::Filter, see "Bundled Courier::Filter loggers" in Courier::Filter::Overview.

For AVAILABILITY, SUPPORT, and LICENSE information, see Courier::Filter::Overview.

AUTHOR

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Julian Mehnle <julian@mehnle.net>

Courier-Filter documentation Contained in the Courier-Filter distribution. 
#
# Courier::Filter::Logger abstract base class
#
# (C) 2003-2008 Julian Mehnle <julian@mehnle.net>
# $Id: Logger.pm 210 2008-03-21 19:30:31Z julian $
#
###############################################################################


package Courier::Filter::Logger;

use warnings;
use strict;

use Error ':try';

use Courier::Error;

use constant TRUE   => (0 == 0);
use constant FALSE  => not TRUE;


# Implementation:
###############################################################################


sub new {
    my ($class, %options) = @_;
    $class ne __PACKAGE__
        or throw Courier::Error('Unable to instantiate abstract ' . __PACKAGE__ . ' class');
    my $self = { %options };
    return bless($self, $class);
}


sub destroy {
    my ($self) = @_;
    return;
}


sub log_error {
    my ($self, $text) = @_;
    return;
}


sub log_rejected_message {
    my ($self, $message, $reason) = @_;
    return;
}


BEGIN {
    no warnings 'once';
    *DESTROY = \&destroy;
}


TRUE;