Silverstripe-framework: Global middleware + custom controller + Controller::curr() triggers `No current controller available`

[jakxnz]

Defining global middleware (as per the middlewares documentation) which invokes a controller that relies on Controller::curr() triggers error No current controller available

---

Version

• silverstripe/framework 4.4.1

Example code

YAML

SilverStripe\Core\Injector\Injector:
  SilverStripe\Control\Director:
    properties:
      Middlewares:
        CustomMiddleware: %$App\Middleware\CustomMiddleware

CustomMiddleware.php

<?php

namespace App\Middleware;

use App\Control\CustomController;
use SilverStripe\Control\HTTPRequest;
use SilverStripe\Control\HTTPResponse;
use SilverStripe\Control\Middleware\HTTPMiddleware;

class CustomMiddleware implements HTTPMiddleware
{

    /**
     * @param HTTPRequest $request
     * @param callable $delegate
     * @return HTTPResponse
     */
    public function process(HTTPRequest $request, callable $delegate): HTTPResponse
    {
        return Injector::inst()->create(CustomController::class)->handleRequest($request);
    }
}

CustomController.php

<?php

namespace App\Control;

use SilverStripe\Control\Controller;
use SilverStripe\Control\HTTPRequest;

class CustomController extends Controller
{

    /**
     * {@inheritdoc}
     *
     * @throws \SilverStripe\Control\HTTPResponse_Exception
     */
    public function handleRequest(HTTPRequest $request)
    {
        // Throw an error exception
        $this->httpError(404);
    }

}

Trace

No current controller available 
Controller.php:556
SilverStripe\Control\Controller::curr() 
ErrorPage.php:106
SilverStripe\ErrorPage\ErrorPage::response_for(404) 
ErrorPageControllerExtension.php:29
SilverStripe\ErrorPage\ErrorPageControllerExtension->onBeforeHTTPError(404, SilverStripe\Control\NullHTTPRequest, , , , , ) 
Extensible.php:468
SilverStripe\View\ViewableData->extend(onBeforeHTTPError, 404, SilverStripe\Control\NullHTTPRequest, ) 
RequestHandler.php:524
SilverStripe\Control\RequestHandler->httpError(404) 
CustomController.php:19

[ScopeyNZ]

This is a valid state of the application. A controller is decided during the main application flow (the inner-most layer of the middleware stack). The controller is then unselected at the end of that flow. Having a controller available with Controller::curr would be a bug imo.

[ScopeyNZ]

As an example of what could be done here - you could adjust the routing information in a middleware based on something in the request - meaning a middleware can help delegate the request to specific controllers - for instance a middleware than handles Accept headers, if you choose to handle different response content types with different controllers.

[dnsl48]

I'm not sure if that would work for you, but it may become available after you delegate the request to the Director.

E.g.:

// Controller::curr() unavailable
$result = $delegate($request);
$controller = Controller::curr(); // should be available here
// ... do something ...
return $result;

P.S. currently it appears that we actually do routing before passing control to the middlewares, so we could potentially pass that info as well (or initialise Controller::curr). However, from this issue description it's not exactly clear what are the potential use cases for that .

[ScopeyNZ]

If the controller state persists after delegating the request, I would consider that a bug.

The controller should be de-allocated after handling the request: https://github.com/silverstripe/silverstripe-framework/blob/f842ee2eec984002fce944157837251fea193b20/src/Control/Controller.php#L219

[ScopeyNZ]

Sorry @jakxnz . I'm going to close this as expected behaviour. Feel free to discuss further and we can re-open if required.