/ 
Message-Passing-0.010
River stage two • 19 direct dependents • 19 total dependents
/ Message::Passing::DSL

NAME

Message::Passing::DSL - An easy way to make chains of Message::Passing components.

SYNOPSIS

package mylogcollectorscript;
use Message::Passing::DSL;

with 'MooseX::GetOpt',
    'Message::Passing::Role::Script';

has socket_bind => (
    is => 'ro',
    isa => 'Str',
    default => 'tcp://*:5558',
);

sub build_chain {
    my $self = shift;
    message_chain {
        output console => (
            class => 'STDOUT',
        );
        input zmq => (
            class => 'ZeroMQ',
            output_to => 'console',
            socket_bind => $self->socket_bind,
        );
    };
}

__PACKAGE__->start unless caller;
1;

DESCRIPTION

This module provides a simple to use helper system for writing scripts which implement a Message::Passing server, like the built in message-pass script.

Rather than having to pass instances of an output to each input in the output_to attribute, and full class names, you can use short names for component classes, and strings for the output_to attribute, the DSL resolves these and deals with instance construction for you.

See example in the SYNOPSIS, and details for the exported sugar functions below.

FUNCTIONS

message_chain

Constructs a message chain (i.e. a series of Message::Passing objects feeding into each other), warns about any unused parts of the chain, and returns an array ref to the heads of the chain (i.e. the input class(es)).

Maintains a registry / factory for the log classes, which is used to allow the resolving of symbolic names in the output_to key to function.

output

Constructs a named output within a chain.

message_chain {
    output foo => ( class => 'STDOUT' );
    ....
};

Class names will be assumed to prefixed with 'Message::Passing::Output::', unless you prefix the class with + e.g. +My::Own::Output::Class

encoder

Constructs a named encoder within a chain.

message_chain {
    encoder fooenc => ( output_to => 'out', class => 'JSON' );
    ....
};

Class names will be assumed to prefixed with 'Message::Passing::Filter::Encoder::', unless you prefix the class with + e.g. +My::Own::Encoder::Class

filter

Constructs a named filter (which can act as both an output and an input) within a chain.

message_chain {
    ...
    filter bar => ( output_to => 'fooenc', class => 'Null' );
    ...
};

Class names will be assumed to prefixed with 'Message::Passing::Filter::', unless you prefix the class with + e.g. +My::Own::Filter::Class

decoder

Constructs a named decoder within a chain.

message_chain {
    decoder zmq_decode => ( output_to => 'filter', class => 'JSON' );
    ....
};

Class names will be assumed to prefixed with 'Message::Passing::Filter::Decoder::', unless you prefix the class with + e.g. +My::Own::Encoder::Class

input

The last thing in a chain - produces data which gets consumed.

message_chain {
    ...
    input zmq => ( output_to => 'zmq_decode', class => 'ZeroMQ', bind => '...' );
    ....
}

Class names will be assumed to prefixed with 'Message::Passing::Output::', unless you prefix the class with + e.g. +My::Own::Output::Class

error_log

Setup the error logging output. Takes the same arguments as an input xxx => () block, except without a name.

run_message_server

This enters the event loop and causes log events to be consumed and processed.

Can be passed a message_chain to run, although this is entirely optional (as all chains which are still in scope will run when the event loop is entered).

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.