mostlygeek · March 20, 2023 18:54 · Mar 20, 2023
diff --git a/main.go b/main.go
@@ -0,0 +1,70 @@
+package main
+
+/*
+This was entirely generated by GPT4 with the prompt:
+
+write me a simple golang server demonstrating server sent events (sse)
+
+*/
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+func main() {
+	http.HandleFunc("/", serveHome)
+	http.HandleFunc("/sse", serveSSE)
+	http.ListenAndServe(":8080", nil)
+}
+
+func serveHome(w http.ResponseWriter, r *http.Request) {
+	html := `<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Server-Sent Events Demo</title>
+</head>
+<body>
+    <h1>Server-Sent Events Demo</h1>
+    <div id="events"></div>
+
+    <script>
+        const eventSource = new EventSource("/sse");
+
+        eventSource.onmessage = (event) => {
+            const eventsDiv = document.getElementById("events");
+            eventsDiv.innerHTML += "<p>" + event.data + "</p>";
+        };
+
+        eventSource.onerror = () => {
+            console.error("Error occurred in EventSource connection.");
+        };
+    </script>
+</body>
+</html>`
+	w.Header().Set("Content-Type", "text/html")
+	w.Write([]byte(html))
+}
+
+func serveSSE(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache")
+	w.Header().Set("Connection", "keep-alive")
+
+	flusher, ok := w.(http.Flusher)
+	if !ok {
+		http.Error(w, "Streaming unsupported!", http.StatusInternalServerError)
+		return
+	}
+
+	for i := 1; ; i++ {
+		fmt.Fprintf(w, "data: Message %d from server\n\n", i)
+		flusher.Flush()
+		time.Sleep(time.Second)
+	}
+
+}