SimplEvent

Simple PHP event listener library.

With the ability to set a priority for each listener, pause/resume, define the number of times a listener can be triggered.

Install

composer require lufiipe/simplevent

Usage

use LuFiipe\SimplEvent\Event;

Event::on('DummyEvent', function () {
    echo 'The dummy event listener has been triggered! <br>';
});

Event::emit('DummyEvent');

Usage with parameter

use LuFiipe\SimplEvent\Event;

Event::on('User.Logged', function ($user) {
    echo sprintf('%s is authenticated! <br>', $user['name']);
});

Event::emit('User.Logged', ['name' => 'John Doe']);

with multiple parameters

use LuFiipe\SimplEvent\Event;

Event::on('registered', function ($email, $ip, $device) {
    echo sprintf('"%s" registered from address "%s" with a "%s". <br>', $email, $ip, $device);
});

Event::emit('registered', '[email protected]', '127.0.0.1', 'mobile');

An event can have multiple listeners.

use LuFiipe\SimplEvent\Event;

Event::on('User.Registered', function ($user) {
    echo 'Log user informations <br>';
});

Event::on('User.Registered', function ($user) {
    echo 'Send email to user <br>';
});

Event::emit('User.Registered', $user);

Notice

Listeners are triggered in the order of their declaration.

Notice

The event name must contain letters, numbers, dots, and underscores.

Priority

Since it is possible to attach multiple listeners to an event, it is also possible to assign a priority to each listener. More the priority value are higher, the sooner the listener will be called.

use LuFiipe\SimplEvent\Event;
use LuFiipe\SimplEvent\ListenerPriority;

Event::on('event.name', function () {
    echo 'Priority 10 <br>';
}, 10);

Event::on('event.name', function () {
    echo 'Priority Max <br>';
}, ListenerPriority::HIGH);

Event::on('event.name', function () {
    echo 'Priority 20 <br>';
}, 20);

Event::emit('event.name');

The above example will output:

Priority Max
Priority 20
Priority 10

Available priority constants

• ListenerPriority::MAX : Max priority
• ListenerPriority::HIGH : High priority
• ListenerPriority::NORMAL : Normal priority (by default)
• ListenerPriority::LOW : Low priority
• ListenerPriority::MIN : MIN priority

Notice

Like closures, priorities cannot be changed once declared.

Pause/Resume

Pause

It is possible to pause the listeners

use LuFiipe\SimplEvent\Event;

$listner = Event::on('Comment.post', function ($comment) {
    echo sprintf('Comment posted: "%s" <br>', $comment);
});

Event::emit('Comment.post', 'Foo');

$listner->pause();

Event::emit('Comment.post', 'Bar');

The above example will output:

Comment posted: "Foo"

Resume

And to resume just use the resume() method of your listener.

use LuFiipe\SimplEvent\Event;

$listner = Event::on('Comment.post', function ($comment) {
    echo sprintf('Comment posted: "%s" <br>', $comment);
});

Event::emit('Comment.post', 'Foo');

$listner->pause();

Event::emit('Comment.post', 'Bar');

$listner->resume();

Event::emit('Comment.post', 'Baz');

The above example will output:

Comment posted: "Foo"
Comment posted: "Baz"

Run the listener multiple times

Specify the number of times the listener can be called.

In this example, the listeners for the "EventX" event will be triggered once.

use LuFiipe\SimplEvent\Event;
use LuFiipe\SimplEvent\ListenerTimes;

Event::on('EventX', function () {
})->setTimes(ListenerTimes::ONCE);

In the example below, listeners will be triggered three times.

use LuFiipe\SimplEvent\Event;

Event::on('Event.dummy', function ($number) {
    echo sprintf("triggered %d time(s) <br>", $number);
})->setTimes(3);

for ($i = 1; $i < 10; $i++) {
    Event::emit('Event.dummy', $i);
}

The above example will output:

triggered 1 time(s)
triggered 2 time(s)
triggered 3 time(s)

Available times constants

• ListenerTimes::ALWAYS : Always listen (by default)
• ListenerTimes::NEVER : Never listen
• ListenerTimes::ONCE : Listen one time

Remove all listeners from an event

Event::unregister('name');

Reset all events

Event::reset();

License

The MIT License (MIT). Please see License File for more information.