cb_method

Relex::Callback::Method's SYNOPSIS has an example, as does the eg directory in Reflex's distribution.

cb_object

cb_object() takes two positional parameters. The first is the object reference that will handle callbacks. The second describes the events and methods that will handle them. It may be a scalar string, an array reference, or a hash reference.

If the second parameter is a scalar string, then a single method will handle a single event. The event and method names will be identical. cb_object() will then return two values: the event name, and the Reflex::Callback::Method to invoke the corresponding object method.

        use Reflex::Callbacks qw(cb_object);
        my $object = bless {};
        my @cbs = cb_object($object, "event");

        # ... is equivalent to:

        use Reflex::Callback::Method;
        my $object = bless {};
        my @cbs = (
                on_event => Reflex::Callback::Method->new(
                        object => $object, method_name => "event"
                )
        );

If the second parameter is an array reference of event names, then one Reflex::Callback::Method will be created for each event. The event names and method names will be identical.

        use Reflex::Callbacks qw(cb_object);
        my $object = bless {};
        my @cbs = cb_object($object, ["event_one", "event_two"]);

        # ... is equivalent to:

        use Reflex::Callback::Method;
        my $object = bless {};
        my @cbs = (
                on_event_one => Reflex::Callback::Method->new(
                        object => $object, method_name => "event_one"
                ),
                on_event_two => Reflex::Callback::Method->new(
                        object => $object, method_name => "event_two"
                ),
        );

If the second parameter is a hash reference, then it should be keyed on event name. The corresponding values should be method names. This syntax allows event and method names to differ.

        use Reflex::Callbacks qw(cb_object);
        my $object = bless {};
        my @cbs = cb_object($object, { event_one => "method_one" });

        # ... is equivalent to:

        use Reflex::Callback::Method;
        my $object = bless {};
        my @cbs = (
                on_event_one => Reflex::Callback::Method->new(
                        object => $object, method_name => "method_one"
                )
        );

cb_class

cb_role

cb_role() requires two parameters and has a third optional one. The first two parameters are the callback object reference and the role of the object for which it handles events. The third optional parameter overrides the "on" prefix with a different one.

        {
                package Handler;
                sub on_resolver_answer { ... }
                sub on_resolver_failure { ... }
        }

        # This role-based definition:

        use Reflex::Callbacks qw(cb_role);
        my $object = Handler->new();
        my @cbs = cb_role($object, "resolver");

        # ... is equivalent to:

        use Reflex::Callbacks qw(cb_object);
        my $object = Handler->new();
        my @cbs = cb_object(
                $object, {
                        answer  => "on_resolver_answer",
                        failure => "on_resolver_failure",
                }
        );

        # ... or:

        use Reflex::Callbacks qw(cb_method);
        my $object = Handler->new();
        my @cbs = (
                on_answer => Reflex::Callback::Method->new(
                        object => $object, method_name => "on_resolver_answer"
                ),
                on_failure => Reflex::Callback::Method->new(
                        object => $object, method_name => "on_resolver_failure"
                ),
        );

cb_promise

cb_promise() returns two values that are suitable to insert onto a Reflex::Base's constructor. The first value is a special event name, "on_promise", that tells Reflex::Base objects they may be used inline as promises. The second return value is the same Reflex::Callback::Promise object that was inserted into cb_promise()'s parameter.

        use Reflex::Callbacks qw(cb_promise);
        my $promise;
        my @cbs = cb_promise(\$promise);

        # ... is eqivalent to:

        use Reflex::Callback::Promise;
        my $promise = Reflex::Callback::Promise->new();
        @cbs = ( on_promise => $promise );

cb_coderef

cb_coderef() neither takes nor returns an event name. As such, the Reflex::Base parameter name must be supplied outside cb_coderef().

        my $timer = Reflex::Interval->new(
                interval    => 1,
                auto_repeat => 1,
                on_tick     => cb_coderef { print "tick!\n" },
        );

As shown above, cb_coderef() is prototyped to make the callback's "sub" declaration optional.

gather_cb

gather_cb() takes three parameters: The object that will own the callbacks, a hash reference containing a constructor's named parameters, and an optional regular expression to match callback parameter names. By default, gather_cb() will collect parameters matching "/^on_/".

        package ThingWithCallbacks;
        use Moose;

        use Reflex::Callbacks qw(gather_cb);

        has cb => ( is => 'rw', isa => 'Reflex::Callbacks' );

        sub BUILD {
                my ($self, $arg) = @_;
                $self->cb(gather_cb($self, $arg));
        }

        sub run {
                my $self = shift;
                $self->cb()->deliver( event => {} );
        }