The Web Platform
March 7–8, 2016: Training
March 8–10, 2016: Conference
San Francisco, CA

Functional reactive JavaScript on the client and the server

Pete Hodgson (Independent)
9:00am–10:30am Tuesday, 03/08/2016
Average rating: ****.
(4.89, 9 ratings)

Prerequisite knowledge

Participants should be comfortable with general JavaScript development and ideally have some experience with both client- and server-side development.

Materials or downloads needed in advance

If attendees wish to follow along with the examples, they will need a laptop with a working Git, Node.js, and npm setup.


The reemergence of functional programming coincides nicely with the JavaScript renaissance. JavaScript’s large collection of features lends it to a functional style of programming. Pete Hodgson explains how to give JavaScript superpowers using a particular branch of the functional style—functional reactive programming (FRP).

FRP provides a unifying abstraction that allows us to write programs without the distracting, accidental complexity of managing state, events, and asyncronous operations. With a single fundamental abstraction—the Observable—we gain a tool which provides the capabilities of promises, event streams, iterables, and more. We can use this unifying abstraction on both the client and server, allowing us to use a truly isomorphic programming style.

Pete demonstrates how to represent streams of events in FRP using Observables and explores how to work with these streams to complete many different tasks. Participants will use this general-purpose tool to build some sample applications which range from reacting to DOM-based user interactions on the client to mashing up third-party APIs on the server.

Photo of Pete Hodgson

Pete Hodgson


Pete Hodgson is an independent software delivery consultant who focuses on enabling software teams to deliver awesome software at a sustainable pace. He blurghs at and toots as @ph1.