PHP code example of stk2k / eventstream

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

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

    

stk2k / eventstream example snippets

use stk2k\eventstream\EventStream;
use stk2k\eventstream\EventSourceInterface;
use stk2k\eventstream\emitter\SimpleEventEmitter;
use stk2k\eventstream\exception\EventSourceIsNotPushableException;
use Stk2k\EventStream\Event;

class NumberEventSource implements EventSourceInterface
{
    protected $numbers;
    
    public function __construct() {
        $this->numbers = ['one', 'two', 'three'];
    }
    public function canPush() : bool {
        return false;
    }
    public function push(Event $event) : EventSourceInterface {
        return $this;
    }
    public function next() {
        $number = array_shift($this->numbers);
        return $number ? new Event('number',$number) : null;
    }
}
  
// create event stream and setup callback, then flush all events
(new EventStream())
    ->channel('my channel', new NumberEventSource(), new SimpleEventEmitter())
    ->listen('number', function(Event $e){
        echo 'received number='.$e->getPayload(), PHP_EOL;
    })
    ->flush();

      
// received number=one
// received number=two
// received number=three
  
// you can not push event to unpushable event source
try{
    (new NumberEventSource())->push(new Even('number','four'));   // throws EventSourceIsNotPushableException
}
catch(EventSourceIsNotPushableException $e){
    echo 'Event not publishable.';
}
  
class PushableNumberEventSource extends NumberEventSource
{
    public function canPush() : bool {
        return true;
    }
    public function push(Event $event) : EventSourceInterface {
        if ($event->getName() === 'number'){
            $this->numbers[] = $event->getPayload();
        }
        return $this;
    }
}
  
// you acn push event to pushable event source
try{
    (new EventStream())
        ->channel('my channel')
        ->source((new PushableNumberEventSource())->push('number','four'))
        ->emitter(new SimpleEventEmitter())
        ->listen('number', function(Event $e){
                echo 'received number='.$e->getPayload(), PHP_EOL;
            })
        ->flush()
        ->push('number', 'five')
        ->flush();
}
catch(EventSourceIsNotPushableException $e){
    echo 'Event not publishable.';
}
  
// received number=one
// received number=two
// received number=three
// received number=four
// received number=five