snapshot of https://github.com/pion/webrtc.git (main, 2026-09-15; blobs > 131072B omitted)

examples/data-channels-simple/main.go

@@ -0,0 +1,148 @@
+// SPDX-FileCopyrightText: 2026 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+//go:build !js
+
+// simple-datachannel is a simple datachannel demo that auto connects.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/pion/webrtc/v4"
+)
+
+func main() {
+	var pc *webrtc.PeerConnection
+
+	setupOfferHandler(&pc)
+	setupCandidateHandler(&pc)
+	setupStaticHandler()
+
+	fmt.Println("🚀 Signaling server started on http://localhost:8080")
+	//nolint:gosec
+	if err := http.ListenAndServe(":8080", nil); err != nil {
+		fmt.Printf("Failed to start server: %v\n", err)
+	}
+}
+
+func setupOfferHandler(pc **webrtc.PeerConnection) {
+	http.HandleFunc("/offer", func(responseWriter http.ResponseWriter, r *http.Request) {
+		var offer webrtc.SessionDescription
+		if err := json.NewDecoder(r.Body).Decode(&offer); err != nil {
+			http.Error(responseWriter, err.Error(), http.StatusBadRequest)
+
+			return
+		}
+
+		// PeerConnection with enhanced configuration for better browser compatibility
+		var err error
+		*pc, err = webrtc.NewPeerConnection(webrtc.Configuration{
+			ICEServers: []webrtc.ICEServer{
+				{URLs: []string{"stun:stun.l.google.com:19302"}},
+			},
+			BundlePolicy:  webrtc.BundlePolicyBalanced,
+			RTCPMuxPolicy: webrtc.RTCPMuxPolicyRequire,
+		})
+		if err != nil {
+			http.Error(responseWriter, err.Error(), http.StatusInternalServerError)
+
+			return
+		}
+
+		setupICECandidateHandler(*pc)
+		setupDataChannelHandler(*pc)
+
+		if err := processOffer(*pc, offer, responseWriter); err != nil {
+			http.Error(responseWriter, err.Error(), http.StatusInternalServerError)
+
+			return
+		}
+	})
+}
+
+func setupICECandidateHandler(pc *webrtc.PeerConnection) {
+	pc.OnICECandidate(func(c *webrtc.ICECandidate) {
+		if c != nil {
+			fmt.Printf("🌐 New ICE candidate: %s\n", c.Address)
+		}
+	})
+}
+
+func setupDataChannelHandler(pc *webrtc.PeerConnection) {
+	pc.OnDataChannel(func(d *webrtc.DataChannel) {
+		d.OnOpen(func() {
+			fmt.Println("✅ DataChannel opened (Server)")
+			if sendErr := d.SendText("Hello from Go server 👋"); sendErr != nil {
+				fmt.Printf("Failed to send text: %v\n", sendErr)
+			}
+		})
+		d.OnMessage(func(msg webrtc.DataChannelMessage) {
+			fmt.Printf("📩 Received: %s\n", string(msg.Data))
+		})
+	})
+}
+
+func processOffer(
+	pc *webrtc.PeerConnection,
+	offer webrtc.SessionDescription,
+	responseWriter http.ResponseWriter,
+) error {
+	// Set remote description
+	if err := pc.SetRemoteDescription(offer); err != nil {
+		return err
+	}
+
+	// Create answer
+	answer, err := pc.CreateAnswer(nil)
+	if err != nil {
+		return err
+	}
+
+	// Set local description
+	if err := pc.SetLocalDescription(answer); err != nil {
+		return err
+	}
+
+	// Wait for ICE gathering to complete before sending answer
+	gatherComplete := webrtc.GatheringCompletePromise(pc)
+	<-gatherComplete
+
+	finalAnswer := pc.LocalDescription()
+	if finalAnswer == nil {
+		//nolint:err113
+		return fmt.Errorf("local description is nil after ICE gathering")
+	}
+
+	responseWriter.Header().Set("Content-Type", "application/json")
+	if err := json.NewEncoder(responseWriter).Encode(*finalAnswer); err != nil {
+		fmt.Printf("Failed to encode answer: %v\n", err)
+	}
+
+	return nil
+}
+
+func setupCandidateHandler(pc **webrtc.PeerConnection) {
+	http.HandleFunc("/candidate", func(responseWriter http.ResponseWriter, r *http.Request) {
+		var candidate webrtc.ICECandidateInit
+		if err := json.NewDecoder(r.Body).Decode(&candidate); err != nil {
+			http.Error(responseWriter, err.Error(), http.StatusBadRequest)
+
+			return
+		}
+		if *pc != nil {
+			if err := (*pc).AddICECandidate(candidate); err != nil {
+				fmt.Println("Failed to add candidate", err)
+			}
+		}
+	})
+}
+
+func setupStaticHandler() {
+	// demo.html
+	http.HandleFunc("/", func(responseWriter http.ResponseWriter, r *http.Request) {
+		http.ServeFile(responseWriter, r, "./demo.html")
+	})
+}