Events

We use the Symfony Event system to manage events at certain points when fetching data. This is useful to add adhoc functionality, such as logging.

The following events are available when accessing data.

Event name	Class constant	Description	Available event methods
data.request.start	StartEvent::NAME	Runs at the start of a request	getRequestId(), getUri(), getContext()
data.request.success	SuccessEvent::NAME	If a request is successful	getRequestId(), getUri(), getContext(), getException()
data.request.failure	FailureEvent::NAME	If a request is considered failed	getRequestId(), getUri(), getContext()
data.request.decode	DecodeEvent::NAME	After response has been decoded	getDecodedData(), getRequestId(), getUri(), getContext()

How to add a listener for a single event

Event listeners are simple callbacks that run when a specific event is dispatched.

Use the addListener(string $eventName, callable $listener, int $priority = 0) method to add a listener to an event. A simple example appears below:

$api->addListener(StartRequest::NAME, function(StartRequest $event) {
    // Get properties from event
    $uri = $event->getUri();
    $context = $event->getContext();

    // Do something at start of data request
});

How to add an event subscriber

An event subscriber is a class that can listen to multiple events. Since it's in a class it's easier to re-use code.

You can add an event subscriber which can listen to multiple events via the addSubscriber(EventSubscriberInterface $subscriber) method.

Available event subscribers

LoggerSubscriber

Add logging for the data request process.

use Strata\Data\Http\Rest;
use Strata\Data\Event\Subscriber\LoggerSubscriber;
use Monolog\Logger;

$api = new Rest();
$api->addSubscriber(new LoggerSubscriber(new Logger('/path/to/log')));

StopwatchSubscriber

Add timing profiling for the Symfony Stopwatch profiler (only recommended in development).

use Strata\Data\Http\Rest;
use Strata\Data\Event\Subscriber\StopwatchSubscriber;
use Symfony\Component\Stopwatch\Stopwatch;

$api = new Rest();
$api->addSubscriber(new StopwatchSubscriber(new Stopwatch());