Assign value to object from within Guzzle on_stats - php

Question

stupid and brief question here,
I've been messing around with trying to get endpoints working on my website for a while now, where an action triggers an endpoint call. I would like to collect stats on call success and average response time and stuff like that, so I create a model prior to making the request, and then attempt to assign object values once the request on_stats stage is reached. The problem is, when I attempt to assign the variables from inside the request, it can't access the object, throwing a Creating default object from empty value error. Guzzle has ways to make things synchronous, using promises, but I've tried and failed to implement them after a variety of errors and attempts to debug. Is there no way to make what I'm attempting to do in the code below work? How could I access the object and assign values from within the request itself?
$call = new EndpointCall;
$call->endpoint_rel_id = $endpt->id;
// Initiate GuzzleHTTP Client
$client = new Client();
$requestQuery = $endpt->endpoint_url;
$response = $client->request('POST', $requestQuery, [
'allow_redirects' => false,
'json' => $obj,
'headers' => [
'api-secret' => $user->api_sending_secret,
'Accept' => 'application/json',
],
'synchronous' => true,
'http_errors' => false,
'on_stats' => function (TransferStats $stats) {
$call->response_time = $stats->getTransferTime();
if ($stats->hasResponse()) {
$call->response = $stats->getResponse()->getStatusCode();
}
$call->save();
}
]);

Answer 1

Try adding use($call) to the function declaration like this:
$call = new EndpointCall;
$call->endpoint_rel_id = $endpt->id;
// Initiate GuzzleHTTP Client
$client = new Client();
$requestQuery = $endpt->endpoint_url;
$response = $client->request('POST', $requestQuery, [
'allow_redirects' => false,
'json' => $obj,
'headers' => [
'api-secret' => $user->api_sending_secret,
'Accept' => 'application/json',
],
'synchronous' => true,
'http_errors' => false,
'on_stats' => function (TransferStats $stats) use($call) {
$call->response_time = $stats->getTransferTime();
if ($stats->hasResponse()) {
$call->response = $stats->getResponse()->getStatusCode();
}
$call->save();
}
]);
About the use keyword
Variables are not accessible inside functions unless they are declared as global. In much the same way, variables from the child scope are not accessible from within the closure unless explicitly stated using the use keyword.