NAME

Beam::Wire - A Dependency Injection Container

SYNOPSIS

    # wire.yml
    dbh:
        class: 'DBI'
        args:
            - 'dbi:mysql:dbname'
            - {
                PrintError: 1
              }
    cache:
        class: 'CHI'
        args:
            driver: 'DBI'
            dbh: { ref: 'dbh' }

    # myscript.pl
    use Beam::Wire;
    my $wire  = Beam::Wire->new( file => 'wire.yml' );
    my $dbh   = $wire->get( 'dbh' );
    my $cache = $wire->get( 'cache' );

    $wire->set( 'dbh', DBI->new( 'dbi:pgsql:dbname' ) );

DESCRIPTION

Beam::Wire is a dependency injection container.

TODO: Explain what a DI container does and why you want it

ATTRIBUTES

file

Read the list of services from the given file. The file is described below in the FILE section.

METHODS

new

Create a new container.

FILE

Beam::Wire can read a YAML file to fill a container with services. The file should be a single hashref. The keys will be the service names.

SERVICE ATTRIBUTES

class

The class to instantiate. The class will be loaded and the new method called.

args

The arguments to the new method. This can be either an array or a hash, like so:

    # array
    dbh: 
        class: DBI
        args:
            - 'dbi:mysql:dbname'

    # hash
    cache:
        class: CHI
        args:
            driver: Memory
            max_size: 16MB

Using the array of arguments, you can give arrayrefs or hashrefs:

    # arrayref of arrayrefs
    names:
        class: 'Set::CrossProduct'
        args:
            -
                - [ 'Foo', 'Barkowictz' ]
                - [ 'Bar', 'Foosmith' ]
                - [ 'Baz', 'Bazleton' ]

    # hashref
    cache:
        class: CHI
        args:
            -   driver: Memory
                max_size: 16MB

INNER CONTAINERS

Beam::Wire objects can hold other Beam::Wire objects!

    inner:
        class: Beam::Wire
        args:
            config:
                dbh:
                    class: DBI
                    args:
                        - 'dbi:mysql:dbname'
                cache:
                    class: CHI
                    args:
                        driver: Memory
                        max_size: 16MB

Inner containers' contents can be reached from outer containers by separating the names with a slash character:

    my $dbh = $wire->get( 'inner/dbh' );