Clear tagged cache from Laravel Lighthouse

Question

I'm trying to integrate caching in to my Laravel (9) Lighthouse (6) application and private caches seem to work correctly, but I can't seem to find a way to clear them effectively without running artisan cache:clear. Take this simplified example: Query me returns authenticated user:

extend type Query @guard {
    me: User @auth @cache(private: true)
}

Then I want to have a query or mutation which sole purpose is to clear this cache. So I created just that:

extend type Mutation @guard {
    userCacheClear(usr_id: ID!): User @update @clearCache(type: "User", idSource: {argument: "usr_id"})
}

My User type looks like this:

type User {
    usr_id: ID! @cacheKey
    usr_username: String
    usr_company: String
}

My problem is that of course userCacheClear returns correct and not cached data, but me returns still cached and at this point outdated result.

Am I missing something from the documentation? Maybe I'm doing something completely wrong?

Answer 1

I couldn't manage to find the exact solution to my problem because for clearing all user related caches there is no common tag. So I overrode the Nuwave\Lighthouse\Cache\CacheDirective::handleField method to include an additional tag to all user private caches.

$tags = [
    $this->cacheKeyAndTags->parentTag($parentName, $rootID),
    $this->cacheKeyAndTags->fieldTag($parentName, $rootID, $fieldName)
];

// If cache is private then adding private tag for easier clearing
if($isPrivate) $tags[] = 'auth_' . $context->user()->getAuthIdentifier();

$cache = $shouldUseTags
    ? $this->cacheRepository->tags($tags)
    : $this->cacheRepository;

From the code you can see that I check if cache should be private and then add a tag auth_{user_id}.

Then registering this change in the AppServiceProvider.php

public function register(): void {
    $this->app->bind(CacheDirective::class, CacheDirectiveAdapter::class);
}

Now I'm free to run this one-liner to clear all GQL private cache for any specific user.

Cache::tags(['auth_{user_id}'])->flush()