hackpack/hacktions

Event library written in hacklang

Hacktions

"hacktions speak louder than words", _(*1)

Events for Hacklang, _(*2)

Usage

Hacktions exposes two traits:, _(*3)

EventEmitter

Run of the mill event emitter with hack type safety., _(*4)

class MyEmitter
{
   use EventEmitter;
}

$emitter = new MyEmitter();

//listeners all use variable argument signatures
$lambda = (...) ==> print(func_get_args()[0]); 
$emitter->on('myevent', $lambda);

//trigger fires all registered events with the given name - can take variable arguments
$emitter->trigger('myevent', 'brian');

$emitter->off('myevent', $lambda); //remove a single listener
$emitter->removeListeners(); //remove all listeners
$emitter->removeListeners('myevent') //remove all 'myevent' events

Subject

Hacktions supports explicit subject/observer relationships:, _(*5)

class Cook
{
    //Cook notifies Waiter objects
    use Subject<Waiter>;

    protected Vector<Burger> $cookedBurgers = {};

    public function cook(Burger $burger): void
    {
        $this->cookedBurgers->add($burger);
        $this->notifyObservers();
    }

    //implement methods to work on cooked items...
}

class Waiter implements Observer<Cook>
{
    //Waiter observes a cook
    public function update(Cook $cook, ...): void
    {
        $burger = $cook->orderUp();
        //deliver burger...
    }
}

The Subject has the following methods:, _(*6)

registerObserver(T $observer): void

Registers a new observer with the subject., _(*7)

removeObserver(T $observer): void

Removes the specified object from the list of observers., _(*8)

notifyObservers(...): void

Notify all observers of a change and optionally pass additional data., _(*9)

Running tests

Tests are written using HackUnit. They can be run with the following:, _(*10)

bin/hackunit Tests/

hhi

As always, make sure to copy hhi files to the project directory if type checking is desired:, _(*11)

cp -r /usr/share/hhvm/hack/hhi /path/to/hacktions