What exactly is @ObjectHolder

[Cerandior]

Lately, after checking a bunch of people's repositories on github for forge 1.10, i have been noticing the ObjectHolder annotation. Now at first i thought it was a java thing, so i googled it but apparantely it's sonething that comes with forge.

 

I am not a professional programmer, and my knowledge of java is very narrow and mostly consists of similarities between it and other languages that i am more experienced with. So when it comes to coding in java ,I usually guess something would work based on my knowledge of other programming languages.

 

So that explains the reason why i don't know much about special java elements. Now back to the main point. What exactly does the ObjectHolder annotation do and why is it used?

[Matryoshika]

Why use it?

-It can pull any object from any registry, during runtime. Including objects from other mods.

 

Why is it useful?

-Let's say I have a mod called "SuperMod", and you want to use one of my blocks, but don't want to use my mod as a dependency. Instead, you can use ObjectHolder to "get" this block at runtime, and thus use it for whatever you want, without having a dependency on my mod.

 

Of course, it is always good to only run this code if "SuperMod" is also loaded. Otherwise, it is going to stay null. (Use

Loader.isModLoaded("modid")

to check!)