provide fallback polling if websocket connection could not be established

static/js/WebSocketChannel.js

@@ -1,4 +1,6 @@
 
+import { getStats } from './api.js';
+
 class WebSocketChannel {
   constructor(){
     this.wsUrl = window.location.protocol.replace("http", "ws") +
@@ -44,9 +46,26 @@ class WebSocketChannel {
       }
     };
 
+		function fallbackPolling(){
+			getStats()
+			.then(function(stats){
+				if (!stats){
+					// no stats (yet)
+					return;
+				}
+
+				var listeners = self.listenerMap["minetest-info"];
+				if (listeners){
+					listeners.forEach(function(listener){
+						listener(stats);
+					});
+				}
+			});
+		}
+
     ws.onerror = function(){
-      //reconnect after some time
+      //fallback to polling stats
-      setTimeout(self.connect.bind(self), 1000);
+      setInterval(fallbackPolling, 2000);
     };
   }
 }

static/js/api.js

@@ -10,3 +10,7 @@ export function getMapObjects(query){
 export function getConfig(){
   return m.request("api/config");
 }
+
+export function getStats(){
+	return m.request("api/stats");
+}

web/minetest.go

@@ -68,6 +68,8 @@ type Minetest struct {
 	ctx *app.App
 }
 
+var LastStats *MinetestInfo
+
 func (this *Minetest) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 	if req.Header.Get("Authorization") != this.ctx.Config.WebApi.SecretKey {
 		resp.WriteHeader(403)
@@ -91,6 +93,7 @@ func (this *Minetest) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 	mintestPlayers.Set(float64(len(data.Players)))
 	mintestMaxLag.Set(data.MaxLag)
 
+	LastStats = data
 	this.ctx.WebEventbus.Emit("minetest-info", data)
 
 	json.NewEncoder(resp).Encode("stub")

web/serve.go

@@ -25,6 +25,7 @@ func Serve(ctx *app.App) {
 	tiles.Init()
 	mux.Handle("/api/tile/", tiles)
 	mux.Handle("/api/config", &ConfigHandler{ctx: ctx})
+	mux.Handle("/api/stats", &StatsHandler{ctx: ctx})
 	mux.Handle("/api/media/", &MediaHandler{ctx: ctx})
 	mux.Handle("/api/minetest", &Minetest{ctx: ctx})
 	mux.Handle("/api/mapobjects/", &MapObjects{ctx: ctx})

web/stats.go

@@ -0,0 +1,16 @@
+package web
+
+import (
+	"encoding/json"
+	"mapserver/app"
+	"net/http"
+)
+
+type StatsHandler struct {
+	ctx *app.App
+}
+
+func (h *StatsHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
+	resp.Header().Add("content-type", "application/json")
+	json.NewEncoder(resp).Encode(LastStats)
+}