[Docs] Add instructions to reinitialize cache for multi-tenancy key settings

[sudkumar]

When switching cache prefix/key/store during a request lifecycle, after the service provider has been loaded, the cache store should be reinitialized to make sure that the updated CacheStore with latest prefix/keys is used for upcoming cache hits.

app()->make(\Spatie\Permission\PermissionRegistrar::class)->initializeCache();

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Context

I have recently integrated laravel-multitenancy in a project to use the per-tenant cache.prefix. I am using single-db multi-tenancy and was setting current Tenant during a request cycle using the Authentication events. This was working perfectly as PermissionRegistrar is a singleton and it was resolved with correct prefix when resolved from the service container. But in some of my flow, I needed to update the permissions for multiple tenants during a single request life cycle. I found out that my database was in correct state with respect to the latest permissions but the permissions cache was not.

After a day or two debugging, I found out that the cache prefix during the loadPermissions was incorrect when updating the permissions of multiple tenants during a single request. Then I logged the CacheStore->getPrefix() and it was incorrect during Tenant switching. That meant the CacheManager was already resolved and was using the old keys in it's store. So I reinitialized the CacheStore in the PermissionRegistrar by calling initializeCache and it resulted in the correct store during TenantSwitching.

Please correct me if I am wrong. I hope this helps someone else as well.

[drbyte]

Thanks