Understanding the mechanism of a chain of methods

Question

I do not understand this for both redux-middleware and apollo-links. How all these functions are executed in sequence and then pass the context to each other Can someone please explain it to me?

Answer 1

The answer was in the Observer pattern. In this pattern, we have an entity (called a subject) that several other entities listen to without knowing how it works (called an observer). As soon as the subject changes, all observers are notified and perform a special operation based on this change. In apollo-link, by defining each link, you generate an independent observerable that listens for apollo-client operation changes.