datachannel: send OpenChannel message

examples/data-channels-create/main.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	"bufio"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"math/rand"
+	"os"
+	"time"
+
+	"github.com/pions/webrtc"
+	"github.com/pions/webrtc/pkg/datachannel"
+	"github.com/pions/webrtc/pkg/ice"
+)
+
+func randSeq(n int) string {
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	letters := []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+	b := make([]rune, n)
+	for i := range b {
+		b[i] = letters[r.Intn(len(letters))]
+	}
+	return string(b)
+}
+
+func main() {
+	reader := bufio.NewReader(os.Stdin)
+	rawSd, err := reader.ReadString('\n')
+	if err != nil && err != io.EOF {
+		panic(err)
+	}
+
+	fmt.Println("")
+	sd, err := base64.StdEncoding.DecodeString(rawSd)
+	if err != nil {
+		panic(err)
+	}
+
+	/* Everything below is the pion-WebRTC API, thanks for using it! */
+
+	// Create a new RTCPeerConnection
+	peerConnection, err := webrtc.New(webrtc.RTCConfiguration{
+		ICEServers: []webrtc.RTCICEServer{
+			{
+				URLs: []string{"stun:stun.l.google.com:19302"},
+			},
+		},
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	// Set the handler for ICE connection state
+	// This will notify you when the peer has connected/disconnected
+	peerConnection.OnICEConnectionStateChange = func(connectionState ice.ConnectionState) {
+		fmt.Printf("Connection State has changed %s \n", connectionState.String())
+	}
+
+	// TODO: We have to send the offer otherwise it's empty.
+
+	d, err := peerConnection.CreateDataChannel("data", nil)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Printf("New DataChannel %s %d\n", d.Label, d.ID)
+
+	d.Lock()
+	d.Onmessage = func(payload datachannel.Payload) {
+		switch p := payload.(type) {
+		case *datachannel.PayloadString:
+			fmt.Printf("Message '%s' from DataChannel '%s' payload '%s'\n", p.PayloadType().String(), d.Label, string(p.Data))
+		case *datachannel.PayloadBinary:
+			fmt.Printf("Message '%s' from DataChannel '%s' payload '% 02x'\n", p.PayloadType().String(), d.Label, p.Data)
+		default:
+			fmt.Printf("Message '%s' from DataChannel '%s' no payload \n", p.PayloadType().String(), d.Label)
+		}
+	}
+	d.Unlock()
+
+	// Set the remote SessionDescription
+	offer := webrtc.RTCSessionDescription{
+		Type: webrtc.RTCSdpTypeOffer,
+		Sdp:  string(sd),
+	}
+	if err := peerConnection.SetRemoteDescription(offer); err != nil {
+		panic(err)
+	}
+
+	// Sets the LocalDescription, and starts our UDP listeners
+	answer, err := peerConnection.CreateAnswer(nil)
+	if err != nil {
+		panic(err)
+	}
+
+	// Get the LocalDescription and take it to base64 so we can paste in browser
+	fmt.Println(base64.StdEncoding.EncodeToString([]byte(answer.Sdp)))
+	fmt.Println("Random messages will now be sent to any connected DataChannels every 5 seconds")
+	for {
+		time.Sleep(5 * time.Second)
+		message := randSeq(15)
+		fmt.Printf("Sending %s \n", message)
+
+		err := d.Send(datachannel.PayloadString{Data: []byte(message)})
+		if err != nil {
+			panic(err)
+		}
+	}
+}