Courier::Filter::Module - An abstract Perl base class for filter modules used by the Courier::Filter framework
0.12
use Courier::Filter::Module::My; # Need to use a non-abstract sub-class. my $module = Courier::Filter::Module::My->new( logger => $logger, inverse => 0, trusting => 0, testing => 0, debugging => 0 ); my $filter = Courier::Filter->new( ... modules => [ $module ], ... );
package Courier::Filter::Module::My; use base qw(Courier::Filter::Module);
Sub-classes of Courier::Filter::Module are used by the Courier::Filter mail filtering framework to determine the acceptability of messages. See Courier::Filter::Overview for an overview of how filter modules are used and for how to write them.
When overriding a method in a derived class, do not forget calling the inherited method from your overridden method.
The following constructor is provided and may be overridden:
Creates a new filter module using the %options. Initializes the filter module, by opening I/O handles, connecting to databases, creating temporary files, initializing parser libraries, etc..
%options is a list of key/value pairs representing any of the following options:
A Courier::Filter::Logger object that will be used for logging message rejections and error messages caused by this individual filter module. If no logger is specified, Courier::Filter's global logger will be used.
A boolean value controlling whether the filter module should operate with inverse polarity (true) as opposed to normal polarity (false). Under inverse polarity, the result of the match method is negated by the consider method before returning it. For details on how Courier::Filter translates match results into acceptability results, see "How Courier::Filter modules work" in Courier::Filter::Overview. Defaults to false.
match
consider
A boolean value controlling whether the filter module should not be applied to trusted messages. For details on how the authenticated status is determined, see the description of the trusted property in Courier::Message. In most configurations, this option can be used to white-list so-called outbound messages. Defaults to false.
trusted
A boolean value controlling whether the filter module should run in testing mode. In testing mode, planned message rejections will be logged as usual, but no messages will actually be rejected. Defaults to false.
A boolean value controlling whether the filter module should log extra debugging information. Defaults to false.
Derived classes may support additional options.
Courier::Filter::Module::new() creates a hashref as an object of the invoked class, and stores the %options in it, but does nothing else.
Courier::Filter::Module::new()
The following destructor is provided and may be overridden:
Uninitializes the filter module, by closing I/O handles, disconnecting from databases, deleting temporary files, uninitializing parser libraries, etc..
Courier::Filter::Module::destroy() does nothing.
Courier::Filter::Module::destroy()
The following instance methods are provided and may be overridden:
Calls the match method, passing it the $message object. Returns the result of match, negating it beforehand if the filter module has inverse polarity. There is usually no need at all to override this method.
Examines the Courier::Message object given as $message. Returns a so-called match result consisting of an SMTP status response text, and an optional numerical SMTP status response code. For details about how match results are used by Courier::Filter, see "How Courier::Filter modules work" in Courier::Filter::Overview and "Writing Courier::Filter modules" in Courier::Filter::Overview.
Courier::Filter::Module::match() does nothing and returns undef.
Courier::Filter::Module::match()
If $logger is specified, installs a new logger for this individual filter module. Returns the current (new) logger.
$logger
Returns a boolean value indicating whether the filter module is operating with inverse polarity, as set through the constructor's inverse option.
inverse
Returns a boolean value indicating whether the filter module does not apply to trusted messages, as set through the constructor's trusting option.
trusting
Returns a boolean value indicating whether the filter module is in testing mode, as set through the constructor's testing option.
testing
If $debugging is specified, sets the debugging mode for this individual filter module. Returns the current (new) debugging mode.
$debugging
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, COPYRIGHT, and LICENSE information, see Courier::Filter::Overview.
Julian Mehnle <julian@mehnle.net>
To install Courier::Filter, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Courier::Filter
CPAN shell
perl -MCPAN -e shell install Courier::Filter
For more information on module installation, please visit the detailed CPAN module installation guide.