Demo

https://vimeo.com/375491031

Details

• From the UI perspective, I used Instagram app as an inspiration. Videos will auto-pay as soon as the user scroll to them and when clicked they will be presented in a new VC (similar to how Instagram transition a video post to IGTV full screen). When the user enters the full-screen view they will be able to pause/play the video and swipe right/left to view other videos.

• The app built using a simple MVC architecture. It contains two VCs, one that displays video posts (MainViewController) and another that displays videos in full screen (PlayerViewController). Storage, API Client, Views and Models are all separated into their own components/classes.

• The tricky part of working with videos in a UICollectionView is AVPlayer cell recycling. My strategy in this app is to load videos when they're visible to the user and remove them when they're not (more precisely when prepareForReuse is called).

• The app uses Coverr APIs (It's similar to unsplash.com but for videos) to get video posts/links.

Note: MainViewController.playVisibleCellVideo() can be called multiple times on the same video when the user scroll. However, only one call will result in creating an AVPlayer, other requests will be ignored (See also VideoPlayerView.play(url:) for more details).

Suggestions on how to improve / expand the features of this app

• Since it’s a simple example app I used MVC. If you would like me to update the sample app to MVVM architecture and add unit/UI test please let me know (that would be my default setup for a large project).

• AVPlayers handling could be moved to a separate manager class. This would provide a smoother transition when animating the player between different views.

• Offline handling.

• Update CoreData and introduce reactive framework to the app (Rx/Combine Swift) to automatically update UI state.