Join egghead, unlock knowledge.

Want more egghead?

This lesson is for members. Join us? Get access to all 3,000+ tutorials + a community with expert developers around the world.

Unlock This Lesson
Become a member
to unlock all features

Level Up!

Access all courses & lessons on egghead today and lock-in your price for life.


    Build an observable from a simple english requirement


    Having built all the event streams we need, we can now assemble them and generate the observable equivalent of our main requirement sentence: “When the loader needs to show, show the loader, until it’s time to hide it”.