jsevent.php

См. документацию.

<?php
 
namespace Bitrix\UI\Buttons;
 
final class JsEvent implements \JsonSerializable
{
    private $event;

    public function __construct($event)
    {
        $this->setEvent($event);
    }

    public function getEvent()
    {
        return $this->event;
    }

    public function setEvent($event)
    {
        if (is_string($event))
        {
            $this->event = $event;
        }
 
        return $this;
    }

    public function jsonSerialize()
    {
        return [
            'event' => $this->getEvent(),
        ];
    }
}