Adding Support for Playing Youtube Videos in SUSI iOS App

SUSI supports very exciting features in chat screen, from simple answer type to complex map, RSS, table etc type responses. Even user can ask SUSI for the image of anything and SUSI response with the image in the chat screen. What if we can play the youtube video from SUSI, we ask SUSI for playing videos and it can play youtube videos, isn’t it be exciting? Yes, SUSI can play youtube videos too. All the SUSI clients (iOS, Android, and Web) support playing youtube videos in chat.

Google provides a Youtube iFrame Player API that can be used to play videos inside the app only instead of passing an intent and playing the videos in the youtube app. iFrame API provide support for playing youtube videos in iOS applications.

In this post, we will see how playing youtube video features implemented in SUSI iOS.

Getting response from server side –

When we ask SUSI for playing any video, in response, we get youtube Video ID in video_play action type. SUSI iOS make use of Video ID to play youtube video. In response below, you can see that we are getting answer action type and in the expression of answer action type, we get the title of the video.

type: "answer",
expression: "Playing Kygo - Firestone (Official Video) ft. Conrad Sewell"
identifier: "9Sc-ir2UwGU",
identifier_type: "youtube",
type: "video_play"

Integrating youtube player in the app –

We have a VideoPlayerView that handle all the iFrame API methods and player events with help of YTPlayer HTML file.

When SUSI respond with video_play action, the first step is to register the YouTubePlayerCell and present the cell in collectionView of chat screen.

Registering the Cell –

register(_:forCellWithReuseIdentifier:) method registers a class for use in creating new collection view cells.

collectionView?.register(YouTubePlayerCell.self, forCellWithReuseIdentifier: ControllerConstants.youtubePlayerCell)


Presenting the YouTubePlayerCell –

Here we are presenting the cell in chat screen using cellForItemAt method of UICollectionView.

if message.actionType == ActionType.video_play.rawValue {
if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: ControllerConstants.youtubePlayerCell, for: indexPath) as? YouTubePlayerCell {
cell.message = message
cell.delegate = self
return cell


Setting size for cell –

Using sizeForItemAt method of UICollectionView to set the size.

if message.actionType == ActionType.video_play.rawValue {
return CGSize(width: view.frame.width, height: 158)

In YouTubePlayerCell, we are displaying the thumbnail of youtube video using UIImageView. Following method is using to get the thumbnail of particular video by using Video ID –

  1. Getting thumbnail image from URL
  2. Setting image to imageView
func downloadThumbnail() {
if let videoID = message?.videoData?.identifier {
let thumbnailURLString = "\(videoID)/default.jpg"
let thumbnailURL = URL(string: thumbnailURLString)
thumbnailView.kf.setImage(with: thumbnailURL, placeholder: ControllerConstants.Images.placeholder, options: nil, progressBlock: nil, completionHandler: nil)

We are adding a play button in the center of thumbnail view so that when the user clicks play button, we can present player.

On clicking the Play button, we are presenting the PlayerViewController, which hold all the player setups, by overFullScreen type of modalPresentationStyle.

@objc func playVideo() {
if let videoID = message?.videoData?.identifier {
let playerVC = PlayerViewController(videoID: videoID)
playerVC.modalPresentationStyle = .overFullScreen
delegate?.loadNewScreen(controller: playerVC)

The methods above present the youtube player with giving Video ID. We are using YouTubePlayerDelegate method to autoplay the video.

func playerReady(_ videoPlayer: YouTubePlayerView) {

The player can be dismissed by tapping on the light black background.

Final Output –

Resources –

  1. Youtube iOS Player API
  2. SUSI API Sample Response for Playing Video
  3. SUSI iOS Link
Continue ReadingAdding Support for Playing Youtube Videos in SUSI iOS App

Add feature to view slides and videos of sessions in Open Event Webapp

The Open Event Web App has two components :

  • An event website generator
  • The actual generated website output.

The web generator application can generate event websites by getting data from event JSON files and binary media files, that are stored in a compressed zip file or through an API endpoint. The JSON data format of version 1 as well as version 2, provides user an option to add the slide and video URLs of the sessions. The data from JSONs is extracted and stored in the objects for a particular session, and in the template, the data for videos and slides are rendered in their corresponding iframes.

Extracting data from event JSONs

The data is extracted from the JSONs and is stored in an object. The object containing the data is sent to the procedure which compiles the handlebars templates with that data.

JSON data format v1

slides: session.slides,


JSON data format v2

video: session['video-url'],
slides: session['slides-url'],
Audio: session['audio-url']


The JSON data format for v1 and v2 are different and thus the data is extracted from the file depending on API version chosen for web app generation. The files where data extraction takes place are fold_v1.js and fold_v2.js for API v1 and v2 respectively.

Adding event emitter

Onclick event emitter on schedule division calls the procedure “loadVideoAndSlides” with the parameters corresponding to the session clicked.

<div class="schedule-track" id="{{session_id}}" onclick = "loadVideoAndSlides('{{session_id}}', '{{video}}', '{{slides}}')">

The parameters Session ID, Video URL and Slide URL are passed to the procedure which is responsible for displaying the slides and video iframes for the sessions. This resolves the problem of heavy data binding to the page, as the frames for videos and slides are loaded on page only when the session is clicked.

Procedure called on click event

The performance of web app is significantly improved by using the call and listen mechanism as only the requested videos are loaded into the document object model.

function loadVideoAndSlides(div, videoURL, slideURL){
 if(videoURL !== null && videoURL !== '') {
     $('#desc-' + div).children('div').prepend(' + div + '" class = "video-iframe col-xs-12 col-sm-12 col-md-12" src="' + videoURL + '" frameborder="0" allowfullscreen>');
 if(slideURL !== null && slideURL !== '') {
     $('#desc-' + div).children('div').prepend(' + div + '" class = "iframe col-xs-12 col-sm-12 col-md-12" frameborder="0" src="' + slideURL  +'">');


The video and slide URLs passed to the procedure are used for loading the iframes from youtube and office apps or google docs respectively as shown above, and the resulting slide view is as shown below


Continue ReadingAdd feature to view slides and videos of sessions in Open Event Webapp