[Solved] [1.16.5] How to make Curios support optional?

[IceMetalPunk]

I haven't made a working mod since 1.12, but I'm starting a new one for 1.16.5 and I'd like it to support the Curios API. I've gotten that working, but I realized that in order to register a Curios slot, I need to reference the Curios API SlotTypeMessage class. I was hoping I could make Curios support optional, i.e. register the slot if the Curios mod is installed, or just gracefully ignore it if not, but if I'm referencing SlotTypeMessage and someone installs my mod without including Curios, won't that just crash? Is there something special I need to do to make the support optional? Or am I totally misunderstanding how dependencies are handled and worrying about crashes that won't happen after all?

Edited May 14, 2021 by IceMetalPunk
Solved

[IceMetalPunk]

15 hours ago, diesieben07 said:

You have to confine classes that interact with the dependency to one part of your mod which must not directly be accessed from anywhere else in your mod. The way you then interact with it is that you have an interface (say CuriosCompat) which is implemented twice. Once for when Curios is not present and once for when it is (this 2nd one can reference Curios classes). Then at startup check if Curios is loaded (the ModList class tells you whether a mod is loaded). If it isn't, instantiate the first implementation. If it is, get the 2nd implementat class using reflection (Class.forName) and create an isntance of it (newInstance()). You cannot reference it directly as otherwise the JVM will try and load this class even though the code is never executed.

Ah! Using reflection to prevent crashing is the trick I needed to know! Thank you, I'll work on implementing it when I get a chance; hopefully it should go smoothly, if not, I'll ask more here with more details.

EDIT Worked perfectly the first try 😁 Thank you for your help!

Edited May 14, 2021 by IceMetalPunk
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