WebRTCChat_createAndSendOffer.js

function createAndSendOffer(){
        if(channel){
            channel.close();
        }

        // Create Data channel
        channel = connection.createDataChannel('channel', {});
        setChannelEvents(channel);

        // Create Offer
        connection.createOffer().then(
            offer => {
                log('Sent The Offer.');

                // Send Offer to other peer
                socket.send(JSON.stringify(
                    {
                        action: 'onMessage',
                        type: 'offer',
                        data: offer,
                        id: clientId
                    }
                ));

                // Set Offer for negotiation
                connection.setLocalDescription(offer);
            },
            error => {
                log('Error when creating an offer.');
                console.error(error);
            }
        );
    }