In-Session Communication

Beyond audio and video, EnableX sessions support a rich set of data communication features: text chat, file sharing, custom signaling, annotation on remote streams, screen sharing, and canvas streaming. None of these features require a published media stream to work — a chat-only participant can send and receive messages without a camera or microphone.

sendMessage() sends a text message to one participant, a group, or everyone in the room. The sender does not need to have a published stream for messaging to work.

• Public messaging — set isBroadcast: true and pass an empty recipientIDs array
• Private / group messaging — set isBroadcast: false and list the target client IDs in recipientIDs

• Method: window.EnxRtc.sendMessage(message, isBroadcast, recipientIDs)

// Public broadcast to everyone
window.EnxRtc.sendMessage("Hello everyone!", true, []);

// Private message to a specific participant
window.EnxRtc.sendMessage("Hi there", false, ["client_id_123"]);

// Sender acknowledgement
window.EnxRtc.addEventListner("onAcknowledgedSendData", function(data) {
    console.log("Message delivered:", JSON.stringify(data.data));
});

// Incoming message at receiver's end
window.EnxRtc.addEventListner("onMessageReceived", function(data) {
    var msg = data.data;
    console.log("New message from:", msg.senderId, "—", msg.message);
    appendMessageToChat(msg);
});

Session participants can share files with each other using a two-step process: the sender uploads the file to the EnableX server, and recipients are notified when the file is ready to download.

Upload a File for Sharing

sendFiles() initiates a file transfer to the EnableX server. You can broadcast the file to all participants or target specific recipients by their client IDs.

• Method: window.EnxRtc.sendFiles(isBroadcast, recipientIDs)

// Send to everyone
window.EnxRtc.sendFiles(true, []);

// --- Sender event listeners ---
window.EnxRtc.addEventListner("onInitFileUpload", function(data) {
    console.log("Upload started:", JSON.stringify(data.data));
});

window.EnxRtc.addEventListner("onFileUploaded", function(data) {
    console.log("File uploaded successfully:", JSON.stringify(data.data));
});

window.EnxRtc.addEventListner("onFileUploadFailed", function(data) {
    console.error("Upload failed:", JSON.stringify(data.data));
});

// --- Receiver event listeners ---
window.EnxRtc.addEventListner("onFileUploadStarted", function(data) {
    console.log("Incoming file upload:", JSON.stringify(data.data));
});

window.EnxRtc.addEventListner("onFileAvailable", function(data) {
    console.log("File ready to download:", JSON.stringify(data.data));
    showDownloadPrompt(data.data);
});

Cancel a File Upload

Cancel a specific in-progress upload by its job ID, or cancel all active uploads at once.

// Cancel a single upload
window.EnxRtc.cancelUpload(jobId);

// Cancel all uploads
window.EnxRtc.cancelAllUploads();

// Event fired when an upload is cancelled
window.EnxRtc.addEventListner("onFileUploadCancelled", function(data) {
    console.log("Upload cancelled:", JSON.stringify(data.data));
});

Download a Shared File

When onFileAvailable fires, the recipient knows a file is ready. Call getAvailableFiles() to retrieve the full list of downloadable files, then call downloadFile() to download a specific one.

// Step 1: Get all files available for download
window.EnxRtc.getAvailableFiles(
    function(data) {
        console.log("Available files:", JSON.stringify(data.data));
        // data.data is an array of file info objects
    },
    function(err) { console.error("Error:", JSON.stringify(err)); }
);

// Step 2: Download a specific file
// fileInfo comes from onFileAvailable or getAvailableFiles
// isAutoSave: true = SDK saves file and returns path
//             false = SDK returns raw Base64 data for manual saving
window.EnxRtc.downloadFile(fileInfo, true);

window.EnxRtc.addEventListner("onInitFileDownload", function(data) {
    console.log("Download started:", JSON.stringify(data.data));
});

window.EnxRtc.addEventListner("onFileDownloaded", function(data) {
    // data.data contains the file path (if autoSave=true) or Base64 data
    console.log("Downloaded:", JSON.stringify(data.data));
});

window.EnxRtc.addEventListner("onFileDownloadFailed", function(data) {
    console.error("Download failed:", JSON.stringify(data.data));
});

Cancel a File Download

// Cancel a single download
window.EnxRtc.cancelDownload(jobId);

// Cancel all active downloads
window.EnxRtc.cancelAllDownloads();

window.EnxRtc.addEventListner("onFileDownloadCancelled", function(data) {
    console.log("Download cancelled:", JSON.stringify(data.data));
});

sendUserData() lets you pass arbitrary structured data to one or more participants. The EnableX server does not enforce any schema on the payload — you define the keys to match your application's needs. Use this to build features like polling, raise-hand mechanisms, or any custom workflow that requires passing data between participants.

• Method: window.EnxRtc.sendUserData(message, isBroadcast, recipientIDs)

// Custom payload — define any structure you need
var message = {
    sender: "John",
    message: "Voting for you",
    candidate: 5,
    rating: 3
};

// Broadcast to everyone
window.EnxRtc.sendUserData(message, true, []);

// Or send to specific participants
window.EnxRtc.sendUserData(message, false, ["client_id_1", "client_id_2"]);

// Sender confirmation
window.EnxRtc.addEventListner("onAcknowledgedSendData", function(data) {
    console.log("Data sent:", JSON.stringify(data.data));
});

// Receiving end
window.EnxRtc.addEventListner("onUserDataReceived", function(data) {
    console.log("Custom data received:", JSON.stringify(data.data));
    handleCustomSignal(data.data);
});

Annotation lets one participant draw and mark up another participant's video stream in real time. The annotator starts annotation on a target client's stream, and all participants in the room are notified.

Start Annotation

• Method: window.EnxRtc.startAnnotation(clientId)
• Parameter: clientId — String. Client ID of the participant whose stream will be annotated

window.EnxRtc.startAnnotation(clientId);

window.EnxRtc.addEventListner("onStartAnnotationAck", function(data) {
    console.log("Annotation started (ack):", JSON.stringify(data.data));
    showAnnotationToolbar();
});

window.EnxRtc.addEventListner("onAnnotationStarted", function(data) {
    console.log("Annotation active (all):", JSON.stringify(data.data));
    showAnnotationIndicator();
});

Stop Annotation

• Method: window.EnxRtc.stopAnnotation()

window.EnxRtc.stopAnnotation();

window.EnxRtc.addEventListner("onStoppedAnnotationAck", function(data) {
    console.log("Annotation stopped (ack):", JSON.stringify(data.data));
    hideAnnotationToolbar();
});

window.EnxRtc.addEventListner("onAnnotationStopped", function(data) {
    console.log("Annotation ended (all):", JSON.stringify(data.data));
    hideAnnotationIndicator();
});

Screen sharing publishes the device's screen as a video stream into the room at 6 fps. It carries on Stream ID 101 — other participants must subscribe to stream ID 101 to receive and display it.

Start Screen Sharing

• Method: window.EnxRtc.addScreenShare(viewOptions, successCallback, errorCallback)
• Event: onScreenSharedStarted — notifies all participants that screen sharing has begun

var viewOptions = {
    height: 130,
    width: 100,
    margin_top: 50,
    margin_left: 0,
    margin_right: 15,
    margin_bottom: 10,
    position: "top"
};

window.EnxRtc.addScreenShare(
    viewOptions,
    function(data) { console.log("Screen share started:", JSON.stringify(data.data)); },
    function(err)  { console.error("Error:", JSON.stringify(err)); }
);

// All participants (including presenter) receive this
window.EnxRtc.addEventListner("onScreenSharedStarted", function(data) {
    console.log("Screen share active:", JSON.stringify(data.data));
    // Subscribe to stream ID 101 to view the shared screen
    subscribeToStream("101");
});

Stop Screen Sharing

• Method: window.EnxRtc.removeScreenShare(successCallback, errorCallback)
• Event: onScreenSharedStopped — notifies all participants that screen sharing ended

window.EnxRtc.removeScreenShare(
    function(data) { console.log("Screen share stopped:", JSON.stringify(data.data)); },
    function(err)  { console.error("Error:", JSON.stringify(err)); }
);

window.EnxRtc.addEventListner("onScreenSharedStopped", function(data) {
    console.log("Screen share ended:", JSON.stringify(data.data));
    removeScreenShare(); // Clean up the view
});

Canvas Streaming publishes any UI view into the room as a video stream. It is carried on Stream ID 102 — participants must subscribe to stream ID 102 to receive the canvas content.

Start Canvas Streaming

• Method: window.EnxRtc.addCanvasScreen(viewOptions, successCallback, errorCallback)
• Event: onCanvasStarted — notifies all participants that canvas streaming began

var options = {
    height: 130,
    width: 100,
    margin_top: 50,
    margin_left: 0,
    margin_right: 15,
    margin_bottom: 10,
    position: "top"
};

window.EnxRtc.addCanvasScreen(
    options,
    function(data) { console.log("Canvas streaming started:", JSON.stringify(data.data)); },
    function(err)  { console.error("Error:", JSON.stringify(err)); }
);

window.EnxRtc.addEventListner("onCanvasStarted", function(data) {
    console.log("Canvas active:", JSON.stringify(data.data));
    // Subscribe to stream ID 102 to view the canvas
    subscribeToStream("102");
});

Stop Canvas Streaming

• Method: window.EnxRtc.removeCanvasScreen(successCallback, errorCallback)
• Event: onCanvasStopped — notifies all participants that canvas streaming ended

window.EnxRtc.removeCanvasScreen(
    function(data) { console.log("Canvas stopped:", JSON.stringify(data.data)); },
    function(err)  { console.error("Error:", JSON.stringify(err)); }
);

window.EnxRtc.addEventListner("onCanvasStopped", function(data) {
    console.log("Canvas ended:", JSON.stringify(data.data));
    removeCanvasScreen(); // Clean up the view
});