Working with capabilities correctly.

[TestingSubject002]

I can't understand how to correctly work with capabilities. For example, I have a Tile Entity which has IItemHandler Capability (1 slot is ok).

@CapabilityInject(IItemHandler.class)
public static final Capability<IItemHandler> ITEM_HANDLER_CAPABILITY = null;

private IItemHandler inventory =
        ITEM_HANDLER_CAPABILITY.getDefaultInstance(); 
// ... hasCapability, getCapability and other stuff

This code was written using McHorse tutorial, is it correct?

 

If yes, then why are we using getDefaultInstance method of ITEM_HANDLER_CAPABILITY which might be null?

 

Sorry for my English.

[TestingSubject002]

So?

[V0idWa1k3r]

  On 1/5/2019 at 4:12 PM, TestingSubject002 said:

@CapabilityInject(IItemHandler.class) public static final Capability<IItemHandler> ITEM_HANDLER_CAPABILITY = null;

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You don't need to get an instance of the capability like this for the IItemHandler since forge provides one for free at CapabilityItemHandler.ITEM_HANDLER_CAPABILITY. You can though, obtaining capability references using CapabilityInject is the way to do this.

 

  On 1/5/2019 at 4:12 PM, TestingSubject002 said:

private IItemHandler inventory = ITEM_HANDLER_CAPABILITY.getDefaultInstance();

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Don't do this for inventories. This method is acceptable for capabilities provided by other mods if you just need the default instance but an inventory capability holds a certain amount of slots, which you declare in it's constructor. Just instantinate ItemStackHandler.

 

  On 1/5/2019 at 6:06 PM, TestingSubject002 said:

So?

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This is a forum, not a chat room, please be patient.

[TestingSubject002]

  On 1/5/2019 at 6:19 PM, V0idWa1k3r said:

You don't need to get an instance of the capability like this for the IItemHandler since forge provides one for free at CapabilityItemHandler.ITEM_HANDLER_CAPABILITY. You can though, obtaining capability references using CapabilityInject is the way to do this.

 

Don't do this for inventories. This method is acceptable for capabilities provided by other mods if you just need the default instance but an inventory capability holds a certain amount of slots, which you declare in it's constructor. Just instantinate ItemStackHandler.

 

This is a forum, not a chat room, please be patient.

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Sorry, this won't repeat again.

 

And what about other capabilities? For example, if I create my own capability, would it be safe to call CAPABILITY.getDefaultInstance() this way or should I do this inside of function annotated @CapabilityInject?

[V0idWa1k3r]

  On 1/5/2019 at 6:27 PM, TestingSubject002 said:

if I create my own capability, would it be safe to call CAPABILITY.getDefaultInstance() this way or should I do this inside of function annotated @CapabilityInject?

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If it's your own capability then you can just instantinate it directly. Use the getDefaultInstance to grab a default instance for a modded capability that you need. In general if you can instantinate it - you probably should. 

I would also recommend reading about capabilities on the official docs, they might answer some of your questions. Feel free to ask if you don't understand something.