NAME

Dancer::Plugin::Chain - Chained actions for Dancer

VERSION

version 0.1.1

SYNOPSIS

    use Dancer;
    use Dancer::Plugin::Chain;

    my $country = chain '/country/:country' => sub {
        # silly example. Typically much more work would 
        # go on in here
        var 'site' => param('country');
    };

    my $event = chain '/event/:event' => sub {
        var 'event' => param('event');
    };

    # will match /country/usa/event/yapc
    get chain $country, $event, '/schedule' => sub {
        return sprintf "schedule of %s in %s\n", map { var $_ } 
                       qw/ event site /;
    };

    my $continent = chain '/continent/:continent' => sub {
        var 'site' => param('continent');
    };

    my $continent_event = chain $continent, $event;

    # will match /continent/europe/event/yapc
    get chain $continent_event, '/schedule' => sub {
        return sprintf "schedule of %s in %s\n", map { var $_ } qw/ event site /;
    };

    # will match /continent/asia/country/japan/event/yapc
    # and will do special munging in-between!

    get chain $continent, 
            sub { var temp => var 'site' },
            $country, 
            sub {
                var 'site' => join ', ', map { var $_ } qw/ site temp /
            },
            $event, 
            '/schedule' 
                => sub {
                    return sprintf "schedule of %s in %s\n", map { var $_ } 
                                qw/ event site /;
            };

DESCRIPTION

Implementation of Catalyst-like chained routes. This kind of behavior can usually be fulfilled by judicious uses of prefix. But hey, diversity is the spice of life, so there you go.

The plugin exports a single keyword, chain, which creates the chained routes.

KNOWN CAVEATS

The plugin only support string-based urls for now (so no regexes).

EXPORTED FUNCTIONS

chain @chain_items, $coderef

Create a chain out of the items provided, and assign it the final action coderef.

Each chain item can be a string representing a path segment, a previously defined chain or an anonymous function. The chain's final path and action will be the aggregate of its parts.

For example, the final route declaration of the SYNOPSIS,

    get chain $continent, 
            sub { var temp => var 'site' },
            $country, 
            sub {
                var 'site' => join ', ', map { var $_ } qw/ site temp /
            },
            $event, 
            '/schedule' 
                => sub {
                    return sprintf "schedule of %s in %s\n", map { var $_ } 
                                qw/ event site /;
            };

would be is equivalent to

    get '/continent/:continent/country/:country/event/:event/schedule' => sub {
        var 'site' => param('continent');
        var temp => var 'site';
        var 'site' => param('country');
        var 'site' => join ', ', map { var $_ } qw/ site temp /
        var 'event' => param('event');

        return sprintf "schedule of %s in %s\n", map { var $_ } 
                        qw/ event site /;
    }

In scalar context, chain returns its underlying object. In list context, it returns a route / action pair of values (). That's how it can work transparently with get, post and friends.

    # returns the object, that can be used to forge longer chains.
    my $foo_chain = chain '/foo', sub { ... };

    # returns the pair that makes 'get' happy
    get chain $foo_chain;

SEE ALSO

• Original blog entry: http://techblog.babyl.ca/entry/dancer-in-chains

• Dancer-Plugin-Dispatcher

AUTHOR

Yanick Champoux <yanick@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2017, 2014 by Yanick Champoux.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.