The Basic-Video-Chat app is a very simple application meant to get a new developer started using the OpenTok iOS SDK.

To use this application:

1. Follow the instructions in the Quick Start section of the main README file for this repository.

   Among other things, you need to set values for the kApiKey, kSessionId, and kToken constants. See Obtaining OpenTok Credentials in the main README file for the repository.

2. When you run the application, it connects to an OpenTok session and publishes an audio-video stream from your device to the session.

3. Run the app on a second client. You can do this by deploying the app to an iOS device and testing it in the simulator at the same time. Or you can use the browser_demo.html file to connect in a browser (see the following section).

   When the second client connects, it also publishes a stream to the session, and both clients subscribe to (view) each other’s stream.

• Follow the code from the ViewController.viewDidLoad(_:) method through to the OpenTok callbacks to see how streams are created and handled in the OpenTok iOS SDK.

• By default, all delegate methods from classes in the OpenTok iOS SDK are invoked on the main queue. This means that you can directly modify the view hierarchy from inside the callback, without any asynchronous callouts.

• When the main view loads, the ViewController calls the OTSession.initWithApiKey(_:, sessionId:,delegate:) method to initialize a Session object. The app then calls the OTSession.connectWithToken(_:, error:) to connect to the session. The OTSessionDelegate.sessionDidConnect(_:) message is sent when the app connects to the OpenTok session.

• The doPublish() method of the app initializes a publisher and passes it into the OTSession.publish(_:,error:) method. This publishes an audio-video stream to the session.

• The OTSessionDelegate.session(_:,streamCreated:) message is sent when a new stream is created in the session. In response, the method calls OTSubscriber(stream:,delegate:), passing in the OTStream object. This causes the app to subscribe to the stream.

To add a second publisher (which will display as a subscriber in your emulator), either run the app a second time in an iOS device or use the OpenTok Playground to connect to the session in a supported web browser (Chrome, Firefox, or Internet Explorer 10-11) by following the steps below:

1. Go to OpenTok Playground (must be logged into your Account)
2. Select the Join existing session tab
3. Copy the session ID you used in your project file and paste it in the Session ID input field
4. Click Join Session
5. On the next screen, click Connect, then click Publish Stream
6. You can adjust the Publisher options (not required), then click Continue to connect and begin publishing and subscribing

• You can test in the iOS Simulator or on a supported iOS device. However, the XCode iOS Simulator does not provide access to the camera. When running in the iOS Simulator, an OTPublisher object uses a demo video instead of the camera.