express-coffee-react-views

Express View Engine for Rendering JSX Components written in CoffeeScript

October 8, 2014

3-Minute Read

This is an Express view engine which renders React components written in CoffeeScript on the server. It renders static markup and does not support mounting those views on the client.

This was derived from express-react-views

This is intended to be used as a replacement for existing server-side view solutions, like jade, ejs, or handlebars.

Usage

npm install express-coffee-react-views react

Note: You must explicitly install react as a dependency. react is a peer dependency here. This is to avoid issues that may come when using incompatible versions.

Add it to your app.

# app.coffee

app = express()

app.set 'view engine', 'cjsx'
app.engine 'cjsx', require('express-coffee-react-views').createEngine()

Options

You can pass options in when creating your engine.

option	values	default
`extension`	any file extension with leading `.`	`".cjsx"`
`doctype`	any string that can be used as a doctype, this will be prepended to your document	`"<!DOCTYPE html>"`
`beautify`	`true`: beautify markup before outputting (note, this can affect rendering due to additional whitespace)	`false`

The defaults are sane, but just in case you want to change something, here’s how it would look:

options =  extension: '.csx'
app.engine 'cjsx', require('express-coffee-react-views').createEngine options

Views

Your views should be node modules that export a React component. Let’s assume you have this file in views/index.cjsx:

/** @cjsx React.DOM */

HelloMessage = React.createClass
  render: ->
    <div>Hello {this.props.name}</div>

module.exports = HelloMessage

Routes

Your routes would look identical to the default routes Express gives you out of the box.

# app.coffee

app.get '/', require('./routes').index

# routes/index.coffee

exports.index = (req, res) ->
  res.render 'index', { name: 'John' }

That’s it! Layouts follow really naturally from the idea of composition.

Layouts

Simply pass the relevant props to a layout component.

views/layouts/default.cjsx:

/** @cjsx React.DOM */

DefaultLayout = React.createClass
  render: ->
    <html>
      <head><title>{this.props.title}</title></head>
      <body>{this.props.children}</body>
    </html>

module.exports = DefaultLayout

views/index.cjsx:

/** @cjsx React.DOM */

DefaultLayout = require './layouts/default'

HelloMessage = React.createClass
  render: ->
    <DefaultLayout title={this.props.title}>
      <div>Hello {this.props.name}</div>
    </DefaultLayout>

module.exports = HelloMessage

Questions

What about partials & includes?

These ideas don’t really apply. But since they are familiar ideas to people coming from more traditional “templating” solutions, let’s address it. Most of these can be solved by packaging up another component that encapsulates that piece of functionality.

What about view helpers?

I know you’re used to registering helpers with your view helper (hbs.registerHelper('something', ...))) and operating on strings. But you don’t need to do that here.

Many helpers can be turned into components. Then you can just require and use them in your view.
You have access to everything else in CoffeeScript. If you want to do some date formatting, you can require('moment') and use directly in your view. You can bundle up other helpers as you please.

Where does my data come from?

All “locals” are exposed to your view in this.props. These should work identically to other view engines.

Using this.props follows the pattern of passing data into a React component, which is why we do it that way.

Remember, as with other engines, rendering is synchronous. If you have database access or other async operations, they should be done in your routes.

Caveats

I’m saying it again to avoid confusion: this does not do anything with React in the browser. This is only a solution for server-side rendering.
This uses require to access your views. This means that the plugin caches the contents for the lifetime of the server process. You need to restart your server when making changes to your views. In development, we clear your view files from the cache so you can refresh your browser to see changes.
React & JSX have their own rendering caveats. For example, inline <script>s and <style>s will need to use dangerouslySetInnerHTML={{__html: 'script content'}}.

<script dangerouslySetInnerHTML={{__html: """
  # google analtyics
  # is a common use
"""}} />

It’s not possible to specify a doctype in JSX. You can override the default HTML5 doctype in the options.

Matt Blair