Pumpkin Plugin Template for Kotlin

This repository provides a template to get started making Pumpkin plugins using WebAssembly (Wasm) components.

Unlike many of the other available language bindings, this repo is a template, not a package. You should clone this repository as a starting point.

Requirements

Kotlin/Wasm + components it's still in it's early stages, and not as straightforward as could be. You will need to have several things installed for everything to work.

• JDK 17 or later
  • To run Gradle 9.4
• Rust
  • This is required as a key component (wit-bindgen) is written and Rust must be built from a particular Kotlin-enabled fork.
  • You only need a default Rust install for your host platform. NOT for any WebAssembly targets
• Make
  • To run the convenience Makefile. You may opt to do without and perform the necessary steps manually.
• wasm-tools
  • To bundle the Wasm Kotlin produces into a component.

Initial setup

To being working on your project, you'll want to adjust the project name in settings.gradle.kts and in the Makefile. Whatever your name you'll project, is what the generated Wasm will be named.

After that, you'll want to run make for the first time. This will setup the toolchain, generate the pumpkin package bindings into src/wasmWasiMain/kotlin/bindings, and build your plugin, leaving it in build/<project-name>.wasm, ready to be installed into Pumpkin.

Then you can tweaking the plugin src in src/wasmWasiMain/kotlin/plugin/Plugin.kt.

Rebuilding

Rebuilding the plugin is as simple as running make again. You can also be more specific by running make componentify to avoid the overhead of checking the wit-bindgen installation and regenerating the bindings.

If you need a debug build instead of a release build, run make componentify-dev (componentify is an alias of componentify-prod). Note that this will make loading the plugin take SIGNFICANTLY longer (making optimized builds actually better for the development loop).

Updating the WIT

Keep an eye on github.com/Pumpkin-MC/pumpkin-plugin-wit

If you start getting errors like main ThreadId(01) pumpkin::plugin: Failed to load plugin from "./plugins\\my_plugin.wasm": Wasm plugin initialization error: plugin failed to load with error: component imports instance 'pumpkin:plugin/gui@0.1.0', but a matching implementation was not found in the linker or other "linker" errors when loading your plugin into Pumpkin, update the wit submodule

cd wit
git pull origin master
cd ..

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Attributions

This template was primarily derived from @jmrtsh's work on Kotlin/sample-wasi-http-kotlin, which is licensed under Apache-2.0