4.x - Add Possibility For Custom RequestHandler Invocation Strategies

[l0gicgate]

This effectively closes #2772 and #2773

Added a new interface for invocation strategies that can handle request handlers:

• RequestHandlerInvocationStrategyInterface

The current RequestHandler strategy now implements that interface which enables to check within the Route::run() method that the user set strategy can handle request handlers. In the event that it doesn't, a new RequestHandler strategy is instantiated.

Also added feature to the existing RequestHandler strategy (requested in #2772/#2773) to append route arguments as attributes to the incoming request object. By default it is set to false. If you want to enable this feature:

To enable the feature for all the routes:

use Slim\Factory\AppFactory;
use Slim\Handlers\Strategies\RequestHandler;

$app = AppFactory::create();

/**
  * The RequestHandler constructor now takes an argument
  * Setting it to true will enable appending the route arguments as attributes to the request
  * @param bool $appendRouteArgumentsToRequestAttributes
 */
$strategy = new RequestHandler(true);
$app->getRouteCollectorProxy()->setDefaultInvocationStrategy($strategy);

To enable the feature on a per route basis:

use Slim\Factory\AppFactory;
use Slim\Handlers\Strategies\RequestHandler;

$app = AppFactory::create();

/**
  * The RequestHandler constructor now takes an argument
  * Setting it to true will enable appending the route arguments as attributes to the request
  * @param bool $appendRouteArgumentsToRequestAttributes
 */
$strategy = new RequestHandler(true);

$route = $app->get(...);
$route->setInvocationStrategy($strategy);

[coveralls]

Coverage remained the same at 100.0% when pulling c9ce864 on l0gicgate:FixInvocationStrategy into 84c96a3 on slimphp:4.x.

[dominikzogg]

@l0gicgate works: https://github.com/chubbyphp/petstore/pull/10/files#diff-1b5ddf350ecbaac353da3e150d9355e4R36