I've been exploring ways to implement real-time inline editing with collaborative features on top of Angular, RxJS and Google Firebase. 

Here are some of the results,
https://www.youtube.com/watch?v=3o0aobCv8Ig

Building elements and complex inline structure:
https://www.youtube.com/watch?v=VrsaFbtzURM

Real-time collaborative features:
https://www.youtube.com/watch?v=GXbiQ1b9ItA&feature=youtu.be