Trying to connect to Stripe API could someone take me through what this webhook is doing step by ste-CodePudding

As the title says I'm trying to use webhooks to automate some of the Stripe events which occur when a customer goes through the subscription process.

In my webhooks.php file these are the bits of code that I don't understand:

/* The are my comments */

// These are comments from the Stripe docs

/* First snippet of code - Not sure what this does? */
$payload = @file_get_contents('php://input');

/* Second snippet of code - Not sure what this does? 
what is the $event variable refering to and why is $payload being 
passed into it? */

$event = null;
try {
    $event = \Stripe\Event::constructFrom(
        json_decode($payload, true)
    );
} catch (\UnexpectedValueException $e) {
    // Invalid payload
    echo '⚠️  Webhook error while parsing basic request.';
    http_response_code(400);
    exit();
}

/* Third snippet of code - I understand the switch and case keywords to 
basically be if and else statements so if the type of the $event variable is 
equal to 'customer.subscription.trial_will_end' then run '$subscription = 
$event -> data -> object'. However what is the $subscription variable being 
assigned to in this case (what does $event -> data -> object mean?) */

// Handle the event
switch ($event->type) {
    case 'customer.subscription.trial_will_end':
        $subscription = $event->data->object; // contains a \Stripe\Subscription
        // Then define and call a method to handle the trial ending.
        // handleTrialWillEnd($subscription);
        break;
    case 'customer.subscription.created':
        $subscription = $event->data->object; // contains a \Stripe\Subscription
        // Then define and call a method to handle the subscription being created.
        // handleSubscriptionCreated($subscription);
        break;
    case 'customer.subscription.deleted':
        $subscription = $event->data->object; // contains a \Stripe\Subscription
        // Then define and call a method to handle the subscription being deleted.
        // handleSubscriptionDeleted($subscription);
        break;
    case 'customer.subscription.updated':
        $subscription = $event->data->object; // contains a \Stripe\Subscription
        // Then define and call a method to handle the subscription being updated.
        // handleSubscriptionUpdated($subscription);
        break;
    default:
        // Unexpected event type
        echo 'Received unknown event type';
}

/* Fourth snippet of code - Why do we need to set this? */
http_response_code(200);

CodePudding user response：

/* First snippet of code - Not sure what this does? */
$payload = @file_get_contents('php://input');

It reads the request body of the HTTP POST request that this script is receiving(a webhook handler is receiving a HTTP request Stripe sends your server). This is a standard PHP idiom.

/* Second snippet of code - Not sure what this does? 
what is the $event variable refering to and why is $payload being 
passed into it? */

$event is the meaningful Event(https://stripe.com/docs/api/events/object) object that is the body of the webhook request. Stripe's PHP library has a function constructEvent to take the incoming request body and parse/convert it to an object you can work with, that's what that code is doing.

However what is the $subscription variable being 
assigned to in this case (what does $event -> data -> object mean?) */

The Event contains a 'payload' object which is the actual API object the event is about. For example if a Subscription is created, you get a customer.subscription.created event and that payload is the Subscription object. It's all covered in Stripe's docs. https://stripe.com/docs/api/events/object#event_object-data-object /// https://stripe.com/docs/api/events/types#event_types-customer.subscription.created

/* Fourth snippet of code - Why do we need to set this? */

Because after receiving this incoming request from Stripe you have to reply back to let them know you got it. https://stripe.com/docs/webhooks/build#acknowledge-events-immediately