Middlewares must take a MiddlewareInterface as their first constructor argument {@see Google\ApiCore\Middleware\ResponseMetadataMiddleware}, which represents the next middleware in the chain. This next middleware MUST be invoked by this MiddlewareInterface, and the result must be returned as part of the __invoke method implementation.
To create your own middleware, first implement the interface, as well as pass the handler in through the constructor:
use Google\ApiCore\Call; use Google\ApiCore\Middleware\MiddlewareInterface; class MyTestMiddleware implements MiddlewareInterface { public function __construct(MiddlewareInterface $handler) { . $this->handler = $handler; } public function __invoke(Call $call, array $options) { echo "Logging info about the call: " . $call->getMethod(); return ($this->handler)($call, $options); } } Next, add the middleware to any class implementing GapicClientTrait by passing in a callable which returns the new middleware:
$client = new ExampleGoogleApiServiceClient(); $client->addMiddleware(function (MiddlewareInterface $handler) { return new MyTestMiddleware($handler); }); AbstractInterface
| Methods |
| public abstract __invoke(Google Modify or observe the API call request and response. The returned value must include the result of the next MiddlewareInterface invocation in the chain.
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