From 33541d18aeabc31c01433fb4858193ecaa8101b1 Mon Sep 17 00:00:00 2001
From: "M. J. Fromberger" <michael.j.fromberger@gmail.com>
Date: Wed, 6 Oct 2021 20:07:20 -0700
Subject: [PATCH] Add websocket server example.

---
 tools/examples/wshttp/server.go | 58 +++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 tools/examples/wshttp/server.go

diff --git a/tools/examples/wshttp/server.go b/tools/examples/wshttp/server.go
new file mode 100644
index 0000000..59ff3e8
--- /dev/null
+++ b/tools/examples/wshttp/server.go
@@ -0,0 +1,58 @@
+// Program wshttp demonstrates how to set up a JSON-RPC 20 server using
+// the github.com/creachadair/jrpc2 package with a Websocket transport.
+//
+// Usage:
+//   go build github.com/creachadair/jrpc2/tools/examples/wshttp
+//   ./wshttp -listen :8080
+//
+// The server accepts RPC connections on ws://<address>/rpc.
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"net/http"
+
+	"github.com/creachadair/jrpc2"
+	"github.com/creachadair/jrpc2/handler"
+	"github.com/creachadair/wschannel"
+)
+
+var listenAddr = flag.String("listen", "", "Service address")
+
+func main() {
+	flag.Parse()
+	if *listenAddr == "" {
+		log.Fatal("You must provide a non-empty -listen address")
+	}
+
+	lst := wschannel.NewListener(nil)
+	hs := &http.Server{Addr: *listenAddr, Handler: http.DefaultServeMux}
+	http.Handle("/rpc", lst)
+	go hs.ListenAndServe()
+
+	srv := jrpc2.NewServer(handler.Map{
+		"Reverse": handler.New(func(_ context.Context, ss []string) []string {
+			for i, j := 0, len(ss)-1; i < j; i++ {
+				ss[i], ss[j] = ss[j], ss[i]
+				j--
+			}
+			return ss
+		}),
+	}, nil)
+
+	ctx := context.Background()
+	for {
+		ch, err := lst.Accept(ctx)
+		if err != nil {
+			hs.Shutdown(ctx)
+			log.Fatalf("Accept: %v", err)
+		}
+		log.Print("Client connected")
+		if err := srv.Start(ch).Wait(); err != nil {
+			log.Printf("Server error: %v", err)
+		}
+		log.Print("Client disconnected (wave bye)")
+	}
+}