is there a possibility to clear or warm up the hole cache over the admin dashboard?
In this case, I have no access to server file system, only to the admin backend.
There is no official way to do so that I know of. But there is the AddonCacheControllers clear() method which is in theory accessible. But it requires an authenticated POST request from a user with admin permissions. Since you are an admin, you can spoof such a request.
The easiest way to do so is to search for a link tag with the class HiJack since such links are hijacked by the framework and sent as a POST request.
Instead of activating the plugin, the cache will be cleared **TADAAA** 😎
This sounds really like a bad hack ;-)
Short test says: "Addon cache cleared"
I will try this live and come back to report.
Thanks a lot.