Implement RxJS `concatMap` by Waiting for Inner Subscriptions to Complete
Unlike mergeMap and switchMap, concatMap focuses on when "inner" subscriptions "complete" by using a "buffer". Each time concatMap receives a value, it adds each value to a "buffer", waits for previous "inner" subscription to complete, then invokes next with the next value from the "buffer".
J. Matthew
~ 6 years ago
Wow, this complex functionality is surprisingly simple to implement...thanks to a very clever design.
As I noted in my comment on the previous video, once again I wasn't able to declare a non-functional property at root on the class—this time buffer—without Webpack's build process breaking. However, the issue was easily solved by appending this.buffer = []; to the end of the constructor.