T11: Declarative, immutable GUIs with ClojureScript, React and Reacl

Abstract

Truly declarative GUIs have been an elusive dream for all functional programmers. Instead, the state of the art in practical GUI programming, even in functional languages, still relies on variations of the MVC model where the program itself needs to align changes in the model with changes in the GUI. This, and circular dependencies between the view and the data, cause the universally hated "callback hell." Facebook's React is frustratingly close to declarative, as it renders the GUI via a pure function from the model. However, React's idea of a model and its event event handling are still fundamentally imperative. The Reacl framework, built on top of React, rectifies this fault and provides purely functional management of rendering, state and event handling to the ClojureScript programmer. This makes Reacl a practical and efficient substrate for frontend programming across almost all platforms: web, mobile, Java, and .NET. More importantly, it makes GUI programming enjoyable again. Come and find out how at this tutorial!

Tutorial objectives

• learn how to compile and deploy ClojureScript/Reacl programs
• learn how write front-end programs using ClojureScript and Reacl
• learn how to leverage HTML5 knowledge to improve GUI design
• enjoy the whole process

Target audience

All functional programmers with an interest in front-end development. No JavaScript knowledge or experience with DOM programming is required. A short introduction to the relevant parts of ClojureScript will be given. Rudimentary familiarity with HTML/CSS is helpful.

Please download the skeleton project for the tutorial with instructions on setup before the tutorial.

Michael Sperber

Mike Sperber is the main author of Reacl. He is also CTO of Active Group, a small software consultancy in Filderstadt, Germany that develops software for client projects using functional programming. He has a long history of publishing on functional programming, including many research papers, and being the project editor for the R6RS standard for the Scheme programming language. He has also developed an introductory course in programming in use at several German university, based on the PLT group's Program by Design approach. Mike is a member of the ICPF, CUFP, and FARM steering committees.