onion/promise

1.0.0 2019-01-21 00:17 UTC

Requires (Dev)

• phpunit/phpunit: ^7.5

MIT

README

This is an Promises/A+ implementation that should be fully compatible with any already existing implementations without any 3rd party dependencies.

This package defines 2 interfaces PromiseInterface & ThenableInterface as per the spec also there are some helper functions as well as some that provide a more sugary feel to the code.

is_thenable - Function that checks if an object is "thenable" coroutine - Push a task as a promise. This one changes it's implementation depending on whether or not the swoole extension is available on the server. If it is then the native coroutines available as go function are used, alternatively it falls back to an approach similar to an event loop.

A tick function is registered using register_tick_function that will invoke 1 task per so that not to bring your application to a complete halt when executing. As well as there is a function registered for shutdown that will run all remaining tasks in a blocking way until the queue is empty - albeit hanging the request.

For when the synchronous mode is used, you should do declare(ticks=1) see the PHP Docs

NOTE: Please, keep in mind that your code will block until the task is processed so this 'mode' is not recommended and users should look at alternative approaches for their heavy tasks or install swoole

async - alias for coroutine, intended to mimic the async keyword in JS/TS/C#

==============

Usage

use \Onion\Framework\Promise\async;

$promise = async(function () use ($orm, $id, $password) {
    $user = $orm->findById($id); // if it throws any exception the promise will immediately get rejected

    if (!$user->isActive()) {
        throw new \RuntimeException('User is not activated yet');
    }

    if (!password_verify($password, $user->getPassword())) {
        throw new \InvalidArgumentException('Invalid password provided');
    }

    return $user;
})->then(function (User $user) use ($paymentService) {
    $paymentService->processUserPayment($user->getId());
    echo "User {$user->getId()} processed successfully";
}, function (\Throwable $ex) {
    echo "Ops.. {$ex->getMessage()}";
})->otherwise(function (\Throwable $ex) {
    // Do something else with the exception maybe ?
})->finally(function () use ($orm) {
    // Regardless of the state change, but it is always called at the end of execution
    $orm->disconnect();
});

The function passed to async/coroutine will be executed immediately so do keep in mind that when using without swoole.