[1.7.10] how do I know when I need the world to be client or server?

[kauan99]

some methods get invoked by both client and server. The ones I'm struggling with at the moment is ItemSword.onUpdate and ArmorItem.onArmorTick.

 

I want to add potion effects to the player while he's holding/wearing an item. But I don't want to do that every tick so I set the potion effect to last a fixed amount of ticks and I perform the check again after that same amount of ticks. Basically, I do entity.addPotionEffect for every Potion on every armor item the player is wearing and also the weapon they're holding, setting the duration of the effect to the next time I will tick the item. Is this supposed to be done server side or client side? If I do it on both sides I get a few weird behaviors like effects lasting longer than they should. I'm currently doing it only when world.isRemote == false (i.e. server side). Is this right?

[Choonster]

Most things should either be done only on the server (if a packet is automatically sent to the clients) or on both sides (if a packet isn't automatically sent).

 

In this case, the server will automatically send a packet to the clients when you add, change or remove a potion effect; so you only need to do it on the server.

[kauan99]

I see. sometimes the client displays the effect ran out, even though it's probably there, because I'm adding it before it can run out. that's because the client haven't received the packet yet right? in those cases, is the potion effect actually active? if such effect was to reduce damage amount from a specific source during OnLivingHurt event, then it would, no matter what the client would think, since that event is only fired on server side. is this correct?

[Choonster]

Yes, the server is the authority on pretty much any calculation; including damage. As long as the potion is active on the server, its effects should work.