WebAppSession

A WebAppSession represents a web-based app running on a TV. You can communicate with a web app by first calling connect() to establish a communication channel, and then listening for “message” events as well as sending your own messages using sendText and sendJSON.

Example:

device.getWebAppLauncher().launchWebApp(webAppId).success(function (session) {
    this.session = session.acquire(); // hold on to a reference

    session.connect().success(function () {
        session.sendText("Hello world");
    });

    session.on('message', function (message) {
        // message could be either a string or an object
        if (typeof message === 'string') {
            console.log("received string message: " + message);
        } else {
            console.log("received object message: " + JSON.stringify(message);
        }
    }, this);

    session.on('disconnect', function () {
        console.log("session disconnected");
        this.session = null;
    }, this);

}, this);

Methods

webAppSession.connect ()

Open a message channel to the app.

Returns: Command

webAppSession.disconnect ()

Close channel to app.

Returns: Command

webAppSession.setWebAppSessionListener ()

Set web app session listener to app

Returns: Command

webAppSession.sendText (text)

Send a text string to the app. Must be connected first.

Parameters:

• text (string) – Text to send to the app

Returns: Command

webAppSession.sendJSON (object)

Send a plain JavaScript object to the app. Must be connected first. If the receiving app does not support non-string messages, the object will be serialized into a string in JSON format.

Parameters:

• object (object) – Plain JavaScript object to send to the app

Returns: Command

webAppSession.close ()

Close the web app.

Returns: Command

Mixin Methods - SimpleEventEmitter

webAppSession.addListener (event, callback, [context])

Add event listener.

Parameters:

• event (string) – name of event
• callback (function) – function to call when event is fired
• context (object) [optional] – object to bind to “this” value when calling function

Returns: object – reference to the same object to allow chaining

webAppSession.removeListener (event, [callback], [context])

Remove event listener with the specified callback and context. If callback is null or undefined, all callbacks for this event will be removed.

Parameters:

• event (string) – name of event
• callback (function) [optional] – function originally passed to addListener
• context (object) [optional] – context object originally passed to addListener

Returns: object – reference to the same object to allow chaining

webAppSession.on (event, callback, [context])

Alias for addListener.

Parameters:

• event (string) – name of event
• callback (function) – function to call when event is fired
• context (object) [optional] – object to bind to “this” value when calling function

Returns: object – reference to the same object to allow chaining

webAppSession.off (event, [callback], [context])

Alias for removeListener.

Parameters:

• event (string) – event name
• callback (function) [optional] – function originally passed to on
• context (object) [optional] – context object originally passed to on

Returns: object – reference to the same object to allow chaining

Mixin Methods - WrappedObject

webAppSession.acquire ()

Indicate that you would like to keep an active reference to this object. Wrapped objects that are not acquired may be freed after the success callback returns.

Returns: object – reference to object

webAppSession.release ()

Release the reference to this object. After calling .release(), this object may no longer be used. You should always release objects when you no longer need them, to avoid memory leaks.