Runtime Events & Utility Functions

The E3DS Frontend SDK provides a set of callbacks and control functions that allow you to monitor session lifecycle events, handle errors gracefully, and extend user experience with custom UI or application logic.

GitHub Source File
https://github.com/e3ds/pixelstreaming-sdk/blob/main/scripts/scripts_demo.js

1. Error Handling & Session Control

Prevent Error Redirect

If enabled, the SDK will not redirect users to an error page on streaming failure.
Developers can instead show their own UI message.

let preventErrorRedirect = true;

onError

Triggered when any streaming or connection error occurs.

e3ds_controller.callbacks.onError = function(errorMsg){
    console.error("onError:", errorMsg);
};

Use Case Examples:

• Show custom “Connection Failed” UI

• Log errors for analytics

• Retry connection logic

onSessionExpired

Called when the authentication session token expires.

e3ds_controller.callbacks.onSessionExpired = function(){
    self.location = "assets/pages/session-expired.htm";
};

Recommended Actions:

• Redirect to your own session expired page

• Regenerate token

• Auto-reconnect flow

2. Connection & Data Channel Events

onConfigAcquire

Called when streaming configuration has successfully been retrieved.

e3ds_controller.callbacks.onConfigAcquire = function(){
    console.log("onConfigAcquire");
};

Use this to:

• Confirm configuration readiness

• Trigger UI state updates

onDataChannelOpen

Fires when the WebRTC data channel with Unreal Engine is successfully opened.

e3ds_controller.callbacks.onDataChannelOpen = function(){
    console.log("onDataChannelOpen");
};

onDataChannelClose

Triggered when the data channel closes.

e3ds_controller.callbacks.onDataChannelClose = function(){
    console.log("onDataChannelClose");
};

Use these to:

• Enable/disable UI controls

• Detect unexpected session drops

3. Unreal Communication

onResponseFromUnreal

Receives messages sent back from Unreal.

e3ds_controller.callbacks.onResponseFromUnreal = function(descriptor){
    console.log("UnrealResponse:", descriptor);
};

Typical Uses:

• Receive gameplay state updates

• Handle UX responses

• Debug Unreal messaging

4. Streaming Progress Events

These callbacks provide real-time progress updates while the app is initializing.

App Acquisition Progress

e3ds_controller.callbacks.onReceivingAppAcquiringProgress = function(percent){
    console.log("App Acquiring:", percent);
};

App Preparation Progress

e3ds_controller.callbacks.onReceivingAppPreparationProgress = function(percent){
    console.log("App Preparing:", percent);
};

App Starting Progress

e3ds_controller.callbacks.onReceivingAppStartingProgress = function(percent){
    console.log("App Starting:", percent);
};

Ideal for:

• Custom loading screens

• Progress bars

• User feedback during startup

5. HTML Binding Event

onHtmlBind

Triggered once HTML and streaming UI are fully bound.

e3ds_controller.callbacks.onHtmlBind = function(){
    console.log("onHtmlBind");
};

Useful when:

• Initializing UI overlays

• Binding custom buttons

• Performing final setup

6. Stream Control Functions

The SDK also exposes several helpful runtime control utilities.

Terminate Stream

Stops the current streaming session.

e3ds_controller.terminate();

Use when:

• User exits experience

• Navigating away from page

• Handling shutdown logic

Control Video Quality

Allows manual control of quality bitrate.

e3ds_controller.setQualityPoint(value);
// Acceptable values: 1 - 51

Note:

• Lower value → higher quality

• Higher value → lower quality

Quality Values

Recommendations

Good for:

• Low bandwidth users

• Performance optimization

Set Stream Volume

e3ds_controller.setVolume(value);
// 0 to 1

Capture Screenshot

e3ds_controller.captureScreenShot();

Toggle Fullscreen

e3ds_controller.toggleFullscreen();

Send Message to Unreal

Allows sending structured messages to Unreal Engine.

e3ds_controller.sendToUnreal(descriptor);

Typical usage:

• Game commands

• UI interactions

• Custom remote controls

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