how to retrieve post response variable outside in reactphp - asynchronous

Question

My code is as follows:
require __DIR__.'/vendor/autoload.php';
use Psr\Http\Message\ResponseInterface;
$loop = React\EventLoop\Factory::create();
$client = new React\Http\Browser($loop);
$data = [
'name' => [
'first' => 'Alice',
'name' => 'Smith',
],
'email' => 'alice#example.com',
'userid' => 'alice',
];
$client->post(
'https://httpbin.org/post',
[
'Content-Type' => 'application/json',
],
json_encode($data)
)->then(function (ResponseInterface $response) {
$response = (string) $response->getBody();
return $response;
});
**echo $response;**
$loop->run();
I am able to get the response inside then function(). but I cannot retrieve the response value outside.
I like to send multiple asynchronous POST requests and collect each responses and echo all of them at once.
How can I access the response variable from outside of post()->then()?

Answer 1

I could get the response when I need a response with deferred and promise method.
First, I assigned the request and response method to $promise.
And I was able to simply get the response with $deferred->resolve();
require __DIR__.'/vendor/autoload.php';
use Psr\Http\Message\ResponseInterface;
$loop = React\EventLoop\Factory::create();
$client = new React\Http\Browser($loop);
$deferred = new React\Promise\Deferred();
$promise = $deferred->promise();
$data = [
'name' => [
'first' => 'Alice',
'name' => 'Smith',
],
'email' => 'alice#example.com',
'userid' => 'alice',
];
$promise = $client->post(
'https://httpbin.org/post',
[
'Content-Type' => 'application/json',
],
json_encode($data)
)->then(function (ResponseInterface $response) {
$response = (string) $response->getBody();
return $response;
});
echo $deferred->resolve();
$loop->run();