PHP code example of co / promise

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

co / promise example snippets

namespace Moebius;

interface PromiseInterface {

    /**
     * Schedule a callback to run when the promise is fulfilled
     * or rejected.
     *
     * @param callable $onFulfill   Callback which will be invoked if the promise is fulfilled.
     * @param callable $onReject    Callback which will be invoked if the promise is rejected.
     * @param callable $void        Ignored; for compataiblity with other promise implementations.
     * @return PromiseInterface     Returns a new promise which is resolved with the return value of $onFulfill/$onReject
     */
    public function then(callable $onFulfill=null, callable $onReject=null, callable $void=null): PromiseInterface;

    /**
     * Is the promise still pending resolution?
     */
    public function isPending(): bool;

    /**
     * Is the promise fulfilled?
     */
    public function isFulfilled(): bool;

    /**
     * Is the promise rejected?
     */
    public function isRejected(): bool;

}

use Moebius\Promise;

$promise = Promise::cast($somePromise);

// Now you can safely check if the promise has been resolved

use Moebius\Promise;

if (Promise::isPromise($someObject)) {
    // You can treat $someObject as a promise
}

$promise = Moebius\Promise::cast($otherPromise);

if (Moebius\Promise::isPromise($otherPromise)) {
    // promise has a valid `then()` method
}

$promise = new Promise(function(callable $fulfill, callable $reject) {
    $fulfill("Hello World");
});
$promise->then(function($value) {
    echo $value."\n";
});

$promise = new Promise();
$promise->then(function($value) {
    echo $value."\n";
});
$promise->resolve("Hello World");

use Moebius\Promise;

function some_future_result() {
    return new Promise(function($fulfill, $reject) {
        /**
         * Either fulfill the promise directly here, by calling
         * the provided $fulfill(VALUE) and $reject(REASON) callbacks
         * immediately, or make sure that one of these are called at
         * a later time.
         */
    });
}

use Moebius\Promise;

function some_future_result() {
    $result = new Promise();

    /**
     * Make sure that the promise is resolved now, by calling
     * `$result->resolve(VALUE)` or `$result->reject(REASON)`
     * here, or make sure that one of them will be called in
     * the future.
     */

    return $result;
}

use Moebius\Promise;

function accepting_a_promise(object $thenable) {
    /**
     * @throws InvalidArgumentException if the object is not a promise
     */
    $promise = Moebius\Promise::cast($thenable);
}

use Moebius\Promise;

function some_function() {
    return new Promise(function($resolve, $reject) {
        // This function is immediately run when constructing the promise

        $resolve("Some value");         // or $reject(new Exception());
    });
}

use Moebius\Promise;

$promise = new Promise();

// send the promise off to some function
some_function($promise);

// resolve it at any later time
$promise->resolve("Some value");    // or $promise->reject(new Exception())