CODEWITHSUNDEEP
javascriptgowebsocket
Haknazar
Haknazar

Reputation: 13

How to fix a server failure when the client reloads the page?

When the client reloads the page, the server issues an error - websocket: close 1001 (going away). When the client reloads the page, does not the websocket connection reconnect? I recently started studying programming, so please forgive if the question is stupid. Client code

var socket = new WebSocket("ws://localhost:8080/ws" );

socket.onmessage = function (event) {
    DownloadScene(event)
}

function DownloadScene(event) {
    var data = JSON.parse(event.data)
    document.getElementById(data.id).innerHTML = data.body;
}
function  loadScene(scene) {
  var page = {
    query_type:"loadScene",
    data : {temp:scene}
}
   var event = JSON.stringify(page);
   socket.send(event);
}

I'm using the gorilla websocket library to build a connection.

Server code

func WebSocketHandler(w http.ResponseWriter, r *http.Request) {

   conn, err := upGrader.Upgrade(w, r, nil)

   if err != nil {
      log.Println(err)
      return
   }
   for { webSocketHandler(conn)}
   defer conn.Close()
}

func webSocketHandler(conn *websocket.Conn) {

  println("new connect")
  err := conn.ReadJSON(&query)
  if err != nil {
      log.Fatal(err)
      return
  }
  switch query.QueryType {
  case "loadScene" :
    err := json.Unmarshal(query.Data,&frames)
    if err!= nil{
        log.Fatal(err)
    }
    var buf  bytes.Buffer
    data := frame.ExecuteTemplate(&buf,"frame",nil)
    if data!=nil{
        log.Fatal(data)
    }
    res,e := json.Marshal(&Frame{"scene",buf.String()})
    if e !=nil{
        log.Println(e)
    }

    errs := conn.WriteMessage(1,res)
    if err!=nil{
        log.Fatal(errs)
    }
 }
}

Upvotes: 1

Views: 1279

Answers (2)

Sepehr GH
Sepehr GH

Reputation: 1387

If on page load websocket connects, then there are no worries. When page refreshes the client will connect to server. you can ignore the exception for websocket close 1001.

Upvotes: 0

tonys
tonys

Reputation: 3984

In go, log.Fatal(..) exits your application. 

err := conn.ReadJSON(&query)

will return an err when the client connection closes and the next block:

if err != nil {
  log.Fatal(err)
  return
}

will close the go server and the Javascript client will be unable to reconnect.

Your server structure also doesn't look quite correct - WebSocketHandler is invoked to handle a single connection:

    .
    http.HandleFunc("/", WebSocketHandler)
    log.Fatal(http.ListenAndServe("localhost:8080", nil))
}

func WebSocketHandler(w http.ResponseWriter, r *http.Request) {
    conn, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        log.Print("Error upgrading websocket:", err)
        return
    }

    defer conn.Close()

    for {
        err = conn.ReadJSON(&query)
        if err != nil {
            log.Print("Error reading query: ", err)
            return
        }
        .
        // -- process query here --
        .
    }
}

Upvotes: 2

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