Mirror's SyncVar behavior

[dmoret]

I’ve come across this article which explains the best practices for using SyncVar

SyncVar Best Practices for Easy Networking - UnityStation

This doesn’t seem to be a Mirror documentation but Mirror is named multiple times in the article and the syntax is the same, so I think this might be the same with Mirror.
However, when using Mirror, these best practices don’t seem to be correct. The Mirror documentation doesn’t cover all these topics, so I’m confused now.

Here are some examples that don’t seem to be the same.

1

The ONLY place you are allowed to change the value of the syncvar field is via the syncvar hook and only on the server! Never change the value on the client side, and never modify the field directly. If you are on the server and you want to change the field value, call the hook method and pass it the new value. This ensures that the hook logic will always be fired on both client and server side.

This doesn’t seem to be correct. If I change a SyncVar directly on the server side in Mirror, it calls the hook on the server. If I call the hook directly from the server and inside the hook I set the SyncVar to the new value (as recommended in the article) the hook gets called twice.

2

(Only if you have a hook method) Override OnStartClient (make sure to use the “override” keyword!) and invoke the hook, passing it the current value of the field. If you are extending a component, make sure to call base.OnStartClient(). This ensures the SyncVar hook is called based on the initial value of the field that the server sends.

In Mirror, the hook seems to get called when the client connects late and the SyncVar is synchronized, I don’t need to call the hook manually in OnStartClient().

3
Another example is the EnsureInit method recommended in the article. I never had any problems with initializing everything in the Awake method. Awake seems to be called before any other Mirror method, but I just can’t be sure about that.

So to conclued, does anyone know how this behaves in Mirror or is there somewhere a proper documentation of this. I just don’t like the idea to make it the way it seems to work for me without knowing how it is properly done.

Thanks for your help

[Joe-Censored]

Unfortunately, the article doesn’t say what version of Mirror was used or even a date for when the article was written. SyncVar hook behavior has had changes a few times.

https://mirror-networking.com/docs/Articles/General/ChangeLog.html

My guess is the article was written against a different version of Mirror than you are using.

[dmoret]

Thanks for your answer, yes the article definitely is outdated.
I have been working testing alot and have to correct my first point:

The SyncVar hook does not get called on the server, only on the clients but of course also on the host (server+client), that is what made me confused.

Points 2 and 3 seem to be correct like, the SyncVar hook gets called when the client connects late und EnsureInit is not needed.