Emyrk/main.go

## main.go
package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"math/rand"
	"net/http"
	"time"
)

type Client struct {
	name   string
	events chan *DashBoard
}
type DashBoard struct {
	User uint
}

func main() {
	mux := http.NewServeMux()
	mux.Handle("/", http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
		writer.Write([]byte(`
		<!DOCTYPE html>
		<div>
			Hello World
		</div>
		<ul id="sse-list">
		</ul>
		<script>
		// JS client
		const source = new EventSource("/sse")
			  source.onmessage = (event) => {
				console.log("OnMessage Called:")
				console.log(event)
				console.log(JSON.parse(event.data))
				const li = document.createElement("li")
				li.innerText = event.data
				document.getElementById('sse-list').append(li);
			  }
		</script>
		`))
	}))
	mux.Handle("/js-copy", http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
		writer.Write([]byte(`
<html>
<body>
<div id="content"></div>

<script type="text/javascript">
    const source = new EventSource('/sse');

    source.addEventListener('message', message => {
        console.log('Got', message);

        // Display the event data in the content div
        document.querySelector('#content').innerHTML = event.data;
    });
</script>
</body>
</html>
		`))
	}))
	mux.Handle("/sse", http.HandlerFunc(dashboardHandler))
	http.ListenAndServe(":3001", mux)
}

func dashboardHandler(w http.ResponseWriter, r *http.Request) {
	client := &Client{name: r.RemoteAddr, events: make(chan *DashBoard, 10)}
	go updateDashboard(client)

	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Access-Control-Allow-Headers", "Content-Type")
	w.Header().Set("Content-Type", "text/event-stream")
	w.Header().Set("Cache-Control", "no-cache")
	w.Header().Set("Connection", "keep-alive")

	timeout := time.After(1 * time.Second)
	select {
	case ev := <-client.events:
		var buf bytes.Buffer
		enc := json.NewEncoder(&buf)
		enc.Encode(ev)
		fmt.Fprintf(w, "data: %v\n\n", buf.String())
		fmt.Printf("data: %v\n", buf.String())
	case <-timeout:
		fmt.Fprintf(w, ": nothing to sent\n\n")
	}

	if f, ok := w.(http.Flusher); ok {
		f.Flush()
	}
}

func updateDashboard(client *Client) {
	for {
		db := &DashBoard{
			User: uint(rand.Uint32()),
		}
		client.events <- db
	}
}
	package main

	import (
	"bytes"
	"encoding/json"
	"fmt"
	"math/rand"
	"net/http"
	"time"
	)

	type Client struct {
	name string
	events chan *DashBoard
	}
	type DashBoard struct {
	User uint
	}

	func main() {
	mux := http.NewServeMux()
	mux.Handle("/", http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
	writer.Write([]byte(`
	<!DOCTYPE html>
	<div>
	Hello World
	</div>
	<ul id="sse-list">
	</ul>
	<script>
	// JS client
	const source = new EventSource("/sse")
	source.onmessage = (event) => {
	console.log("OnMessage Called:")
	console.log(event)
	console.log(JSON.parse(event.data))
	const li = document.createElement("li")
	li.innerText = event.data
	document.getElementById('sse-list').append(li);
	}
	</script>
	`))
	}))
	mux.Handle("/js-copy", http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
	writer.Write([]byte(`
	<html>
	<body>
	<div id="content"></div>

	<script type="text/javascript">
	const source = new EventSource('/sse');

	source.addEventListener('message', message => {
	console.log('Got', message);

	// Display the event data in the content div
	document.querySelector('#content').innerHTML = event.data;
	});
	</script>
	</body>
	</html>
	`))
	}))
	mux.Handle("/sse", http.HandlerFunc(dashboardHandler))
	http.ListenAndServe(":3001", mux)
	}

	func dashboardHandler(w http.ResponseWriter, r *http.Request) {
	client := &Client{name: r.RemoteAddr, events: make(chan *DashBoard, 10)}
	go updateDashboard(client)

	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Access-Control-Allow-Headers", "Content-Type")
	w.Header().Set("Content-Type", "text/event-stream")
	w.Header().Set("Cache-Control", "no-cache")
	w.Header().Set("Connection", "keep-alive")

	timeout := time.After(1 * time.Second)
	select {
	case ev := <-client.events:
	var buf bytes.Buffer
	enc := json.NewEncoder(&buf)
	enc.Encode(ev)
	fmt.Fprintf(w, "data: %v\n\n", buf.String())
	fmt.Printf("data: %v\n", buf.String())
	case <-timeout:
	fmt.Fprintf(w, ": nothing to sent\n\n")
	}

	if f, ok := w.(http.Flusher); ok {
	f.Flush()
	}
	}

	func updateDashboard(client *Client) {
	for {
	db := &DashBoard{
	User: uint(rand.Uint32()),
	}
	client.events <- db
	}
	}