List of Contents

Chestnut mostly combines the work of others to give you everything you need. It's good to have a basic idea of what each of these does.

React

React is a library for building user interfaces. It was created by Facebook to help them develop their applications.

Its distinguising features are reactive data flow, and a virtual DOM. This means your UI automatically updates when your data changes. The virtual DOM lets React very efficiently figure out the changes in the UI. In React you define components that each render a piece of data.

Om

Om provides a ClojureScript interface to React. By relying on Clojurescripts's persistent data structures it can be even faster than plain react.

There are a few other Clojurescript wrappers for React, each with their merits. But if you're using Chestnut, you get Om.

Figwheel

Figwheel powers the instant reloading of Clojurescript and CSS. When the application loads in the browser, it will connect to the Figwheel server. Whenever you save a Clojurescript or CSS file, Figwheel will recompile it, and send it to the browser. No page refresh required!

Weasel

In Clojure and other Lisps it's common to make heavy use of a REPL (read-eval-print-loop, i.e. a command line interface) during development. Evaluating Clojurescript requires a Javascript environment, such as provided by your browser.

Weasel gives you a REPL for Clojurescript. It will wait for a browser to load and connect, so that it can send code to the browser to be evaluated. This way you can interact live with your running application.

Ring

Many web applications also have a server-side component, even for just an API. The HTML page containing the Clojurescript app also needs to be served from somewhere. There are a number of HTTP servers available for this. Chestnut gives you the choice between Jetty and HTTP Kit.

Ring provides a common interface for your app to communicate with a web server.

Ring also makes it easy to set up middleware that does extra processing as part of a web request/response cycle. Chestnut sets up a Ring middleware that handles hot reloading of server-side code.

Compojure

Compojure is a "concise routing library for Ring". It lets you configure request handlers based on HTTP method and URL patterns.

Enlive

Enlive a selector based HTML templating and transformation system. We use this to inject some development workflow related bits into index.html.