Golang WebAssembly Async Loader
Generates a WASM package from Golang and provides an async interface for working with it
Install
npm install --save-dev golang-wasm-async-loader
This is a loader for webpack that is used for generating WebAssembly (aka WASM) bundles from Go.
The JavaScript bridge that is then generated for webpack will expose the WebAssembly functions as a Promise for interacting with.
webpack config
module.exports = {
...
module: {
rules: [
{
test: /\.go/,
use: ['golang-wasm-async-loader']
}
]
},
node: {
fs: 'empty'
}
};
Using in your code
You import your Go code just like any other JavaScript module you might be working with. The webpack loader will export a default export that has the functions you registered in Go on it. Unfortunately it currently doesn't provide autocomplete of those function names as they are runtime defined.
import wasm from './main.go'
async function init() {
const result = await wasm.add(1, 2);
console.log(result);
}
Here's the main.go
file:
package main
import (
"strconv"
"syscall/js"
"github.com/aaronpowell/webpack-golang-wasm-async-loader/gobridge"
)
func add(i ...js.Value) js.Value {
ret := 0
for _, item := range i {
val, _ := strconv.Atoi(item.String())
ret += val
}
return js.ValueOf(ret)
}
func main() {
c := make(chan struct{}, 0)
gobridge.RegisterCallback("add", add)
<-c
}
How does it work?
As part of this repository a Go package has been created to improve the interop between the Go WASM runtime and work with the async pattern the loader defines.
To do this a function is exported from the package called RegisterCallback
which takes two arguments:
- A
string
representing the name to register it as in JavaScript (and what you'll call it using)
- The
func
to register as a callback
- Note: The
func
must has a signature of (args ...js.Value) js.Value
and you are responsible to box/unbox the JavaScript values to the appropriate Go types. Similarly you need to box the return type as a js.Value
In JavaScript a global object is registered as __gobridge__
which the registrations happen against.
Licence
MIT
Credit
Aaron Powell