isClassExtendedWith doesnt work in Controller::extend

[Quendi6]

Winter CMS Build

1.2.9 and 1.2.11

PHP Version

8.3

Database engine

MySQL/MariaDB

Plugins installed

No response

Issue description

It is not possible to use isClassExtendedWith when extending a controller. This example from the documentation https://wintercms.com/docs/v1.2/docs/services/behaviors#extending-a-clas generates an Exception if the controller is already extended using the same behavior:

UsersController::extend(function ($controller) {
    // Implement behavior if not already implemented
    if (!$controller->isClassExtendedWith(\Backend\Behaviors\RelationController::class)) {
        $controller->implement[] = \Backend\Behaviors\RelationController::class;
    }

    // Define property if not already defined
    if (!isset($controller->relationConfig)) {
        $controller->addDynamicProperty('relationConfig');
    }

    // Splice in configuration safely
    $myConfigPath = '$/myvendor/myplugin/controllers/users/config_relation.yaml';

    $controller->relationConfig = $controller->mergeConfig(
        $controller->relationConfig,
        $myConfigPath
    );
}

Exception

Class Backend\Controllers\Users has already been extended with Backend\Behaviors\RelationController

With ExtendableTrait::extendableConstruct() the order seems to be:

1. First: all extend() callbacks are run (including yours).
2. Then: the behaviors listed in $implement are applied (including RelationController).

And isClassExtendedWith() returns true only when the behavior has already been applied (i.e. when it is present in extensionData['extensions']).

Steps to replicate

When UsersController already implement \Backend\Behaviors\RelationController::class, try this in boot() on your Plugin.php:

UsersController::extend(function ($controller) {
    // Implement behavior if not already implemented
    if (!$controller->isClassExtendedWith(\Backend\Behaviors\RelationController::class)) {
        $controller->implement[] = \Backend\Behaviors\RelationController::class;
    }
}

You can try with other controllers and other behaviors, like \Backend\Behaviors\FormController::class or \Backend\Behaviors\ListController::class for example. Same issue.

Workaround

No response

[mjauvin]

Does the same happen with previous releases?

[Quendi6]

Yes, that's the case in version 1.2.9. And I haven't tried it, but after checking, it seems to be the case in all Storm versions, same in OctoberCMS before the Winter fork.

[Quendi6]

I would suggest modifying the isClassExtendedWith method in ExtendableTrait, but with the approach I have in mind (checking $this->implement), the semantics become slightly broader ("declared or applied") instead of strictly "applied". For use inside extend(), that is exactly what we want, but it may not be ideal everywhere.

[mjauvin]

It doesn't make sense, that method is used all over the system, and I personally use it in many of my plugins without issue.

[Quendi6]

I use it too, the problem lies solely in Controller::extend(). For example, with Event::listen('backend.page.beforeDisplay', function ($controller, $action, $params){});, it works perfectly.

[Quendi6]

And of course, you will never have an exception if you implement a behavior only once.

[Quendi6]

I have a plugin that uses isClassExtendedWith 17 times, and for good reason, and it works like a charm. However, only one of these occurrences is in Backend\Controllers\Users::extend(), which implements \Backend\Behaviors\RelationController::class for the first time in 1.2.11 (maybe 1.2.10, this wasn't the case in version 1.2.9), something I had already done in my plugin. That's why, upon upgrading, I noticed this issue.

[mjauvin]

I see two ways to fix this without breaking anything:

1. we modify extendClassWith() to only apply the extension if it's not extended already and not throw the exception
2. we modify extendableConstruct() to remove duplicates in $implement[]

[mjauvin]

@Quendi6 please see if wintercms/storm#225 fixes the issue for you.

[Quendi6]

Neat fix. Good job 👍