Best way to read data from Websockets

Question

I'm learning Go (Golang) and had a project in mind. The project would be a web app that pulls in a data stream from a 3rd party websocket. At this point, I'm trying to get my Go project to read the web socket data so I can parse it.

The 3rd party websocket is a data stream of JSON objects.

So far I've been able to successfully listen to the websocket. However, I'm confused on how to best deal with this. Namely, the read method I'm using on the Websocket library is getting a slice of bytes. Which seems challenging to turn into JSON objects. Is there a better way to read the websocket - collecting the JSON objects?

Goal

My goal is to listen to this public web socket, get json objects - which I can parse for a field of my desire which would then be pulled into a view (dynamically updating with the data stream.)

If not, how can I convert the slice of bytes back to a JSON object?

Code

Here's my code:

    package main

import (
    "golang.org/x/net/websocket"
    "fmt"
    "log"
)

func main(){

    origin := "http://localhost/"
    url := "wss://ws-feed.gdax.com"
    ws, err := websocket.Dial(url, "", origin)
    if err != nil {
        log.Fatal(err)
    }
    if _, err := ws.Write([]byte(`{"type":"subscribe", "product_ids":["LTC-USD"]}`)); err != nil {
        log.Fatal(err)
    }
    var msg = make([]byte, 512)
    var n int
    for 1>0{
        if n, err = ws.Read(msg); err != nil {
            log.Fatal(err)
        }
        fmt.Printf("Received: %s.\n", msg[:n])
    }
}

Answer 1

First, don't use websocket.Read and websocket.Write to read/write from/to a websocket - better use the convenience websocket.Message object and its corresponding websocket.Message.Receive() and websocket.Message.Send() functions. Both of them are used to send strings in UTF-8 encoding or a sequence of bytes.

If you are expecting JSON objects to be sent on the socket, you better use websocket.JSON.Receive() instead of websocket.Message.Receive.

Use it as follows:

    ...    
    type Person struct {
      Name string
      Emails []string
    }

    func ReceivePerson(ws *websocket.Conn) {
      var person Person
      err := websocket.JSON.Receive(ws, &person)
      if err != nil {
         log.Fatal(err)
      }
    ...