[11.x] Add methods to the HTTP kernel to append middleware relative to other middleware

[ollieread]

This PR allows for the programmatic insertion of middleware into the priority, relative to existing prioritised middleware.

Reasoning

My thought behind this is that third-party package developers can now register the priority of their middleware without requiring the user to mess with it themselves. I am currently developing a package where the priority of middleware will depend on several factors, so mostly, I need this. XD

Methods

Kernel::addToMiddlewarePriorityRelative()

This method adds middleware to the Kernel::$middlewarePriority property relative to other middleware. This method is protected and exists for the other two methods.

Kernel::addToMiddlewarePriorityAfter()

This method adds middleware to the Kernel::$middlewarePriority property after existing middleware.

$kernel->addToMiddlewarePriorityAfter(
    \Illuminate\Routing\Middleware\ValidateSignature::class,
    [
        \Illuminate\Cookie\Middleware\EncryptCookies::class,
        \Illuminate\Contracts\Auth\Middleware\AuthenticatesRequests::class,
    ],
);

The above adds the ValidateSignature middleware to the priority list after the two provided pieces of middleware, ensuring that it will run after them.

This method also accepts a string and not just an array, so you can insert after a single piece of middleware.

Kernel::addToMiddlewarePriorityBefore()

This method adds middleware to the Kernel::$middlewarePriority property before existing middleware.

$kernel->addToMiddlewarePriorityBefore(
    \Illuminate\Routing\Middleware\ValidateSignature::class,
    [
        \Illuminate\Cookie\Middleware\EncryptCookies::class,
        \Illuminate\Contracts\Auth\Middleware\AuthenticatesRequests::class,
    ],
);

The above adds the ValidateSignature middleware to the priority list before the two provided pieces of middleware, ensuring that it will run before them.

This method also accepts a string and not just an array, so you can insert before a single piece of middleware.

[leewillis77]

Just adding a +1 here that I'd definitely find these methods useful!