# README

GopheRPC

GopheRPC is a RPC library that lets you call Go server functions from your JavaScript (browser) clients without any additional dependencies or code generation.

Server functions can be added on runtime (even after the client has connected to the server) and can return any value or error that is JSON serializable.
Return values on client side are wrapped in a Promise.

package main

import (
	"context"
	"net/http"

	"github.com/tsukinoko-kun/gopherpc"
)

func main() {
	gopherpc.Register("foo", func(ctx context.Context, args []any) (any, error) {
		return "bar", nil
	})

	// Use HandleFunc, Handle or Get depending on the mux you are using.
	// Tested with net/http and chi router.
	gopherpc.HandleFunc(http.DefaultServeMux)

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/html")
		w.Write([]byte(`<!DOCTYPE html>
			<html>
				<head>
					<title>GopherPC</title>
				</head>
				<body>` +
					gopherpc.ImportJs() + // script tag that imports the gopherpc.js runtime
					`<button onclick="gopherpc.foo().then(alert)">Call foo</button>
				</body>
			</html>`))
	})

	if err := http.ListenAndServe(":8080", nil); err != nil {
		panic(err)
	}
}

Args

Use gopherpc.Unmarshal to parse your []any args into a struct.

The order of the args is the same as the order of the fields in the struct.
You can override this by using the index tag.

type Args struct {
	Name   string
	Email  string
	Loaded bool   `index:"-"`
	Phone  string `index:"2"`
}

gopherpc.Register("foo", func(ctx context.Context, args []any) (any, error) {
	var a Args
	if err := gopherpc.Unmarshal(args, &a); err != nil {
		return nil, err
	}

	return a.Name + " " + a.Email + " " + a.Phone, nil
})