How is Unity's ExecuteEvents.Execute supposed to be used?

Question

I'm just starting with Unity and got pretty excited when I saw that the Event System existed, and I could create custom events. The event I need is 'IInventoryMessage::NewItemInInventory', so I went ahead and created the interface for that, set it up on my Inventory.

Then it came time to trigger the event, and the documentation threw me a little.

ExecuteEvents.Execute<IInventoryMessage>(target, null, (x,y)=>x.NewItemInInventory());

My confusion is that it seems to be passing in the target.

My hope was the Unity would keep track of all the components with the message's interface and call that when it was executed. But it seems I have to pass in the GameObject myself.

Is it the case that I'm supposed to keep a list of all the GameObjects I want to receive the message, and the loop over them to pass them into Execute? Why do I need the EventSystem at that point, if I'm already looping over the objects I know need to be called?

Answer 1

I use ExecuteEvents only inside my custom input system where the target it's always known and up to date (according to the pointer raycast). Whenever I want to send a message or trigger an action when something happened, I use the standard C# events, as BugFinder said.