Chapter 7
Building Reactive Forms in Angular

Initially defined in 1999, the <form> element has powered the web ever since. Web forms started out as an obtuse collection of inputs that only validated when the user submitted the entire form, resetting everything if one detail was off. In the modern era, our users expect much more from forms. Our forms need to load quickly, respond with inline validation, and save the user’s state so nothing is lost due to a connection hiccup or page refresh. Angular sprinkles RxJS liberally across its form tooling with the ReactiveForms module, bringing a decades-old element up to the cutting edge.

This chapter walks you through creating a set of forms for a pizza shop, showcasing the many features of reactive forms along the way. At first, the focus will be on a single input element, slowly composing in more functionality until you’ve created an impressively functional set of web forms, all built on an observable backbone.