Go WebAssembly 入门（一）

已经安装 Go 1.11及以上版本。

Getting Started

编辑main.go

package main

import "fmt"

func main() {
    fmt.Println("Hello, Go WebAssembly!")
}

把main.go build成WebAssembly(简写为wasm)二进制文件

GOOS=js GOARCH=wasm go build -o lib.wasm main.go

把JavaScript依赖拷贝到当前路径

cp "$(go env GOROOT)/misc/wasm/wasm_exec.js" .

创建一个index.html文件，并引入wasm_exec.js文件，调用刚才build的lib.wasm

<html>
    <head>
        <meta charset="utf-8">
        <script src="wasm_exec.js"></script>
        <script>
            const go = new Go();
            WebAssembly.instantiateStreaming(fetch("lib.wasm"), go.importObject).then((result) => {
                go.run(result.instance);
            });
        </script>
    </head>
    <body></body>
</html>

创建server.go监听8080端口，serve当前路径

package main

import (
  "flag"
  "log"
  "net/http"
)

var (
  listen = flag.String("listen", ":8080", "listen address")
  dir    = flag.String("dir", ".", "directory to serve")
)

func main() {
  flag.Parse()
  log.Printf("listening on %q...", *listen)
  err := http.ListenAndServe(*listen, http.FileServer(http.Dir(*dir)))
  log.Fatalln(err)
}

启动服务

go run server.go

在浏览器访问localhost:8080,打开浏览器console，就可以看到输出 Hello, Go WebAssembly! 。

reference

• https://github.com/golang/go/wiki/WebAssembly