tutorial:interface_injection
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| tutorial:interface_injection [2022/03/08 21:06] – moved from the mixin inject page juuz | tutorial:interface_injection [2025/10/09 14:18] (current) – solidblock | ||
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| - | ======= | + | ======= |
| This is a new technique introduced by Loom 0.11 to add methods into a specific existing class. | This is a new technique introduced by Loom 0.11 to add methods into a specific existing class. | ||
| Line 7: | Line 7: | ||
| This is particularly useful for libraries, with this you can add new methods to existing classes and use them without the need of casting or reimplementing the interface every time. | This is particularly useful for libraries, with this you can add new methods to existing classes and use them without the need of casting or reimplementing the interface every time. | ||
| + | |||
| + | Fabric API takes advantage of this technique. For example, '' | ||
| Let's explain better with an example: | Let's explain better with an example: | ||
| - | The scope of this example is to add the following method into FlowableFluid | + | The scope of this example is to add the following method into ''< |
| - | This, normally, is not possible because | + | This, normally, is not possible because |
| - | <code java [enable_line_numbers=" | + | <yarncode |
| - | Optional< | + | Optional< |
| - | </code> | + | </yarncode> |
| To add the method into the class, first of all you need to create an interface with it: | To add the method into the class, first of all you need to create an interface with it: | ||
| - | <code java [enable_line_numbers=" | + | <yarncode |
| package net.fabricmc.example; | package net.fabricmc.example; | ||
| public interface BucketEmptySoundGetter { | public interface BucketEmptySoundGetter { | ||
| - | // The methods in an injected interface MUST be default, | + | default Optional< |
| - | // otherwise code referencing them won't compile! | + | |
| - | default Optional< | + | |
| return Optional.empty(); | return Optional.empty(); | ||
| } | } | ||
| } | } | ||
| - | </code> | + | </yarncode> |
| - | Now you need to implement this interface | + | :!: The method body in the interface |
| - | <code java [enable_line_numbers=" | + | ℹ️ It's highly recommended to add a dollar-character or underscore character with the mod name as the prefix or suffix of the method name, in order to avoid method name conflict with other mods. |
| - | @Mixin(FlowableFluid.class) | + | |
| + | Now you need to implement this interface into ''< | ||
| + | |||
| + | <yarncode | ||
| + | @Mixin(class_3609.class) | ||
| public class MixinFlowableFluid implements BucketEmptySoundGetter { | public class MixinFlowableFluid implements BucketEmptySoundGetter { | ||
| @Override | @Override | ||
| - | public Optional< | + | public Optional< |
| - | //This is how to get the default sound, copied from BucketItem class. | + | |
| - | return Optional.of(((FlowableFluid) (Object) this).isIn(FluidTags.LAVA) ? SoundEvents.ITEM_BUCKET_EMPTY_LAVA | + | |
| } | } | ||
| } | } | ||
| - | </code> | + | </yarncode> |
| - | Lastly you need to inject the interface into FlowableFluid. | + | Lastly you need to inject the interface into ''< |
| - | The following snippet can be added to your fabric.mod.json file to add one or more interfaces to the net/minecraft/ | + | The following snippet can be added to your '' |
| Note that all class names here must use the " | Note that all class names here must use the " | ||
| - | <code json [enable_line_numbers=" | + | < |
| { | { | ||
| " | " | ||
| Line 60: | Line 64: | ||
| Now you can use the new method: | Now you can use the new method: | ||
| - | <code java [enable_line_numbers=" | + | <yarncode |
| - | Optional< | + | Optional< |
| - | </code> | + | </yarncode> |
| + | |||
| + | You could also override this method in classes extending ''< | ||
| - | You could also override | + | Sometimes, your interface injections may need to include the '' |
tutorial/interface_injection.1646773596.txt.gz · Last modified: 2022/03/08 21:06 by juuz