Introduction to Transforming Streams

When dealing with streams, one of the most frequent use cases you’ll face is the need to transform a stream of certain values into a stream of other values. And this is what this chapter is about. We’ll start by explaining the requirement that we’ll resolve by transforming streams. It’s about implementing autosave behavior in the recipe app. Then we’ll explore the imperative way of implementing this feature. Following that, we’ll learn the declarative pattern for doing it and study the most commonly used RxJS transformation operators for this situation.

Defining the requirement

The user can add a new recipe by clicking the “New Recipes” menu item. This will display the following form to be filled out: