NAME

       Message::Passing::Role::Filter - Simple abstraction for filtering messages

SYNOPSIS

           package My::Filter;
           use Moo;
           use namespace::clean -except => 'meta';

           with 'Message::Passing::Role::Filter';

           sub filter {
               my ($self, $message) = @_;
               # Do something with $message
               return $message; # Or return undef to halt message!
           }

           1;

DESCRIPTION

       Both a producer and a consumer of messages, able to filter out messages based upon their
       contents, or permute the structure of messages.

REQUIRED METHODS

   filter
       Called to filter the message. Returns the mangled message.

       Note if you return undef then the message is not propagated further up the chain, which
       may be used for filtering out unwanted messages.

REQUIRED ATTRIBUTES

   output_to
       From Message::Passing::Role::Input.

METHODS

   consume
       Consumers a message, calling the filter method provided by the user with the message.

       In the case where the filter returns a message, outputs the message to the next step in
       the chain.

SEE ALSO

       Message::Passing
       Message::Passing::Manual::Concepts

SPONSORSHIP

       This module exists due to the wonderful people at Suretec Systems Ltd.
       <http://www.suretecsystems.com/> who sponsored its development for its VoIP division
       called SureVoIP <http://www.surevoip.co.uk/> for use with the SureVoIP API -
       <http://www.surevoip.co.uk/support/wiki/api_documentation>

AUTHOR, COPYRIGHT AND LICENSE

       See Message::Passing.