function EventBus() {
this.events = [];

this.register=function(event, callback){
if(!this.events[event]) {
this.events[event] = [];
}
this.events[event].push(callback);
}

this.fire=function(event, payload){
if(this.events[event]) {
this.events[event].forEach(subscriber => {
subscriber(payload);
})
}
}
}

function Receiver(){
this.value="";

this.init=function(){
this.EventBus.register("update", (payload) => {
this.value = payload.value;
});
this.cjsPushBindings();
};
}

function Sender(){
this.values=[
'Blubb',
'Test',
'Brumm',
'Event',
'Something'
];

this.send=function(event){
this.EventBus.fire("update", {value: this.values[Math.floor(Math.random() * this.values.length)]})
};
}

<div cjs-controller="sender:Sender" cjs-services="EventBus">
<input type="button" value="fire event" cjs-binding-event="click:send"/>
</div>
<div cjs-controller="receiver:Receiver:init" cjs-services="EventBus">
<input type="text" value="" cjs-binding-value="value"/>
</div>

echo json_encode($result);
die();

composer require api

namespace hp\examples\api\entity;

use ApiPlatform\Core\Annotation\ApiProperty;
use ApiPlatform\Core\Annotation\ApiResource;
use Doctrine\ORM\Mapping as ORM;

/**
* Example-Resource
*
* @ORM\Entity
* @ORM\Table(name="blubb")
*
* @ApiResource(
* )
*/
class Blubb {
/**
* @var int
*
* @ORM\Column(name="id", type="integer", nullable=false)
* @ORM\Id
* @ORM\GeneratedValue(strategy="IDENTITY")
*
* @ApiProperty(
* identifier=true
* )
*/
private $id;

/**
* @var string
*/
private $value = ''

....
....
....
}

api_platform:
mapping:
paths: ['%kernel.project_dir%/src/examples/api/entity']
patch_formats:
json: ['application/merge-patch+json']
swagger:
versions: [3]

api_platform:
resource: .
type: api_platform
prefix: /api/examples/

php bin/console debug:router

namespace hp\examples\api\entity;

class BlubbIn {
public $value;
public $logComment;
}

namespace hp\examples\api\entity;

class BlubbOut {
public $id;
public $value;
public $md5sum;
}

namespace hp\examples\api\entity\transformer;

use ApiPlatform\Core\DataTransformer\DataTransformerInterface;

class BlubbInTransformer implements DataTransformerInterface {
public function transform($object, string $to, array $context = []) {
$entity = new Blubb();
$entity->setValue($object->value);

\hp\Logger::log($object->logComment);
return $entity;
}

public function supportsTransformation($data, string $to, array $context = []): bool
{
return $to === Blubb::class && null !== ($context['input']['class'] ?? null);
}
}

namespace hp\examples\api\entity\transformer;

use ApiPlatform\Core\DataTransformer\DataTransformerInterface;

class BlubbOutTransformer implements DataTransformerInterface {
public function transform($object, string $to, array $context = []) {
$dto = new BlubbOut();
$dto->id = $object->getId();
$dto->value = $object->getValue();
$dto->md5sum = md5($object->getValue() . $object->getId());
return $dto;
}

public function supportsTransformation($data, string $to, array $context = []): bool
{
return $to === BlubbOut::class && $data instanceof Blubb;
}
}

...

/**
* Example-Resource
*
* @ORM\Entity
* @ORM\Table(name="blubb")
*
* @ApiResource(
* input=hp\examples\api\entity\BlubbIn::class,
* output=hp\examples\api\entity\BlubbOut::class
* )
*/

...

...

/**
* Example-Resource
*
* @ORM\Entity
* @ORM\Table(name="blubb")
*
* @ApiResource(
* attributes={"security"="is_granted('EXAMPLE_API_ACTION')"},
* input=hp\examples\api\entity\BlubbIn::class,
* output=hp\examples\api\entity\BlubbOut::class
* )
*/

...

namespace namespace hp\examples\api\security;

use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
use Symfony\Component\Security\Core\Authorization\Voter\Voter;

class ExampleAPIVoter extends Voter {

...
...
...

protected function supports($attribute, $subject) {
return $attribute == 'EXAMPLE_API_ACTION';
}

protected function voteOnAttribute($attribute, $subject, TokenInterface $token) {
return $this->apiKey == $this->getUserRequestApiKey();
}
}