webidl-book-library

webidl-book-library

This component showcases building WebAssembly components that line up with WebIDL interfaces by using the experimental built-in support for WebIDL in jco.

We can accomplish this by:

• Writing WebIDL specifications
• Using webidl2wit to turn WebIDL specifications into WIT interfaces
• Using jco componentize to build Javascript WebAssembly components that target the relevant WIT interfaces
• Using jco transpile to compile that component to run in a JS context (like NodeJS)
• Writing host bindings (demo.js) that WebAssembly cna use

A common use case for WebIDL is targeting browsers, as the WebIDL is primarily used there to document interfaces for the web platform. This example stops short of using the web platform WebIDL in favor of showing a simpler modeled interace with WebIDL: a book library (see ./book-library.webidl).

Dependencies

To run this example, you'll need the following tools

Tool	Description	Install instructions
jco	Javascript WebAssembly toolcahin	npm install -g @bytecodealliance/jco
webidl2wit	Converts WebIDL to WIT	cargo install --locked webidl2wit-cli

Quickstart

Once dependencies are installed, you can use your favorite NodeJS package manager to run the steps:

npm install
npm run generate:wit
npm run generate:types
npm run build
npm run transpile

Note

To run all these steps at once, you can run npm run all

After running the component build, we can run the example code that uses our WebAssembly component, and the WebIDL interface & implementation we made:

node demo.js