[![Gem](https://img.shields.io/gem/v/react-rails.svg?style=flat-square)](http://rubygems.org/gems/react-rails) [![Build Status](https://img.shields.io/travis/reactjs/react-rails/master.svg?style=flat-square)](https://travis-ci.org/reactjs/react-rails) [![Gemnasium](https://img.shields.io/gemnasium/reactjs/react-rails.svg?style=flat-square)](https://gemnasium.com/reactjs/react-rails) [![Code Climate](https://img.shields.io/codeclimate/github/reactjs/react-rails.svg?style=flat-square)](https://codeclimate.com/github/reactjs/react-rails) [![Test Coverage](https://img.shields.io/codeclimate/coverage/github/reactjs/react-rails.svg?style=flat-square)](https://codeclimate.com/github/reactjs/react-rails/coverage) * * * # react-rails `react-rails` makes it easy to use [React](http://facebook.github.io/react/) and [JSX](http://facebook.github.io/react/docs/jsx-in-depth.html) in your Ruby on Rails (3.2+) application. `react-rails` can: - Provide [various `react` builds](#reactjs-builds) to your asset bundle - Transform [`.jsx` in the asset pipeline](#jsx) - [Render components into views and mount them](#rendering--mounting) via view helper & `react_ujs` - [Render components server-side](#server-rendering) with `prerender: true` - [Generate components](#component-generator) with a Rails generator - [Be extended](#extending-react-rails) with custom renderers, transformers and view helpers Just getting started with React? Make sure to check out the [Getting Started] (https://facebook.github.io/react/docs/getting-started.html) guide. ## Installation Add `react-rails` to your gemfile: ```ruby gem 'react-rails', '~> 1.4.0' ``` Next, run the installation script: ```bash rails g react:install ``` This will: - create a `components.js` manifest file and a `app/assets/javascripts/components/` directory, where you will put your components - place the following in your `application.js`: ```js //= require react //= require react_ujs //= require components ``` ## Usage ### React.js builds You can pick which React.js build (development, production, with or without [add-ons]((http://facebook.github.io/react/docs/addons.html))) to serve in each environment by adding a config. Here are the defaults: ```ruby # config/environments/development.rb MyApp::Application.configure do config.react.variant = :development end # config/environments/production.rb MyApp::Application.configure do config.react.variant = :production end ``` To include add-ons, use this config: ```ruby MyApp::Application.configure do config.react.addons = true # defaults to false end ``` After restarting your Rails server, `//= require react` will provide the build of React.js which was specified by the configurations. `react-rails` offers a few other options for versions & builds of React.js. See [VERSIONS.md](https://github.com/reactjs/react-rails/blob/master/VERSIONS.md) for more info about using the `react-source` gem or dropping in your own copies of React.js. ### JSX After installing `react-rails`, restart your server. Now, `.js.jsx` files will be transformed in the asset pipeline. `react-rails` currently ships with two transformers, to convert jsx code - * `BabelTransformer` using [Babel](http://babeljs.io), which is the default transformer. * `JSXTransformer` using `JSXTransformer.js` You can use the deprecated `JSXTransformer` by setting it in an application config: ```ruby config.react.jsx_transformer_class = React::JSX::JSXTransformer ``` #### BabelTransformer options You can use babel's [transformers](http://babeljs.io/docs/advanced/transformers/) and [custom plugins](http://babeljs.io/docs/advanced/plugins/), and pass [options](http://babeljs.io/docs/usage/options/) to the babel transpiler adding following configurations: ```ruby config.react.jsx_transform_options = { blacklist: ['spec.functionName', 'validation.react'], # default options optional: ["transformerName"], # pass extra babel options whitelist: ["useStrict"] # even more options } ``` Under the hood, `react-rails` uses [ruby-babel-transpiler](https://github.com/babel/ruby-babel-transpiler), for transformation. #### JSXTransformer options You can use JSX `--harmony` or `--strip-types` options by adding a configuration: ```ruby config.react.jsx_transform_options = { harmony: true, strip_types: true, # for removing Flow type annotations asset_path: "path/to/JSXTransformer.js", # if your JSXTransformer is somewhere else } ``` ### Rendering & mounting `react-rails` includes a view helper (`react_component`) and an unobtrusive JavaScript driver (`react_ujs`) which work together to put React components on the page. You should require the UJS driver in your manifest after `react` (and after `turbolinks` if you use [Turbolinks](https://github.com/rails/turbolinks)). The __view helper__ puts a `div` on the page with the requested component class & props. For example: ```erb <%= react_component('HelloMessage', name: 'John') %>
``` On page load, the __`react_ujs` driver__ will scan the page and mount components using `data-react-class` and `data-react-props`. If Turbolinks is present components are mounted on the `page:change` event, and unmounted on `page:before-unload`. __Turbolinks >= 2.4.0__ is recommended because it exposes better events. The view helper's signature is: ```ruby react_component(component_class_name, props={}, html_options={}) ``` - `component_class_name` is a string which names a globally-accessible component class. It may have dots (eg, `"MyApp.Header.MenuItem"`). - `props` is either an object that responds to `#to_json` or an already-stringified JSON object (eg, made with Jbuilder, see note below). - `html_options` may include: - `tag:` to use an element other than a `div` to embed `data-react-class` and `-props`. - `prerender: true` to render the component on the server. - `**other` Any other arguments (eg `class:`, `id:`) are passed through to [`content_tag`](http://api.rubyonrails.org/classes/ActionView/Helpers/TagHelper.html#method-i-content_tag). ### Server rendering To render components on the server, pass `prerender: true` to `react_component`: ```erb <%= react_component('HelloMessage', {name: 'John'}, {prerender: true}) %>

Hello, John!

``` _(It will be also be mounted by the UJS on page load.)_ There are some requirements for this to work: - `react-rails` must load your code. By convention it uses `components.js`, which was created by the install task. This file must include your components _and_ their dependencies (eg, Underscore.js). - Your components must be accessible in the global scope. If you are using `.js.jsx.coffee` files then the wrapper function needs to be taken into account: ```coffee # @ is `window`: @Component = React.createClass render: -> `` ``` - Your code can't reference `document`. Prerender processes don't have access to `document`, so jQuery and some other libs won't work in this environment :( You can configure your pool of JS virtual machines and specify where it should load code: ```ruby # config/environments/application.rb # These are the defaults if you dont specify any yourself MyApp::Application.configure do # Settings for the pool of renderers: config.react.server_renderer_pool_size ||= 1 # ExecJS doesn't allow more than one on MRI config.react.server_renderer_timeout ||= 20 # seconds config.react.server_renderer = React::ServerRendering::SprocketsRenderer config.react.server_renderer_options = { files: ["react-server.js", "components.js"], # files to load for prerendering replay_console: true, # if true, console.* will be replayed client-side } end ``` - On MRI, use `therubyracer` for the best performance (see [discussion](https://github.com/reactjs/react-rails/pull/290)) - On MRI, you'll get a deadlock with `pool_size` > 1 - If you're using JRuby, you can increase `pool_size` to have real multi-threaded rendering. ### Rendering components instead of views Components can also be prerendered directly from a controller action with the custom `component` renderer. For example: ```ruby class TodoController < ApplicationController def index @todos = Todo.all render component: 'TodoList', props: { todos: @todos }, tag: 'span', class: 'todo' end end ``` This custom renderer behaves the same as a normal view renderer and accepts the usual arguments - `content_type`, `layout`, `location` and `status`. By default, your current layout will be used and the component, rather than a view, will be rendered in place of `yield`. Custom data-* attributes can be passed like `data: {remote: true}`. ### Component generator `react-rails` ships with a Rails generator to help you get started with a simple component scaffold. You can run it using `rails generate react:component ComponentName (--es6)`. The generator takes an optional list of arguments for default propTypes, which follow the conventions set in the [Reusable Components](http://facebook.github.io/react/docs/reusable-components.html) section of the React documentation. For example: ```shell rails generate react:component Post title:string body:string published:bool published_by:instanceOf{Person} ``` would generate the following in `app/assets/javascripts/components/post.js.jsx`: ```jsx var Post = React.createClass({ propTypes: { title: React.PropTypes.string, body: React.PropTypes.string, published: React.PropTypes.bool, publishedBy: React.PropTypes.instanceOf(Person) }, render: function() { return (
Title: {this.props.title}
Body: {this.props.body}
Published: {this.props.published}
Published By: {this.props.publishedBy}
); } }); ``` #### Options **--es6** : Generate the same component but using cutting edge es6 class For example: ```shell rails generate react:component Label label:string --es6 ``` **--coffee** : Generate the component using CoffeeScript syntax For example: ```shell rails generate react:component Label label:string --coffee ``` #### Arguments The generator can use the following arguments to create basic propTypes: * any * array * bool * element * func * number * object * node * shape * string The following additional arguments have special behavior: * `instanceOf` takes an optional class name in the form of {className}. * `oneOf` behaves like an enum, and takes an optional list of strings in the form of `'name:oneOf{one,two,three}'`. * `oneOfType` takes an optional list of react and custom types in the form of `'model:oneOfType{string,number,OtherType}'`. Note that the arguments for `oneOf` and `oneOfType` must be enclosed in single quotes to prevent your terminal from expanding them into an argument list. ### Jbuilder & react-rails If you use Jbuilder to pass a JSON string to `react_component`, make sure your JSON is a stringified hash, not an array. This is not the Rails default -- you should add the root node yourself. For example: ```ruby # BAD: returns a stringified array json.array!(@messages) do |message| json.extract! message, :id, :name json.url message_url(message, format: :json) end # GOOD: returns a stringified hash json.messages(@messages) do |message| json.extract! message, :id, :name json.url message_url(message, format: :json) end ``` ## CoffeeScript It is possible to use JSX with CoffeeScript. To use CoffeeScript, create files with an extension `.js.jsx.coffee`. We also need to embed JSX code inside backticks so that CoffeeScript ignores the syntax it doesn't understand. Here's an example: ```coffee Component = React.createClass render: -> `` ``` Alternatively, the newer ES6 style class based syntax can be used like this: ```coffee class Component extends React.Component render: -> `` ``` ## Extending `react-rails` You can extend some of the core functionality of `react-rails` by injecting new implementations during configuration. ### Custom Server Renderer `react-rails` depends on a renderer class for rendering components on the server. You can provide a custom renderer class to `config.react.server_renderer`. The class must implement: - `#initialize(options={})`, which accepts the hash from `config.react.server_renderer_options` - `#render(component_name, props, prerender_options)` to return a string of HTML `react-rails` provides two renderer classes: `React::ServerRendering::ExecJSRenderer` and `React::ServerRendering::SprocketsRenderer`. `ExecJSRenderer` offers two other points for extension: - `#before_render(component_name, props, prerender_options)` to return a string of JavaScript to execute _before_ calling `React.render` - `#after_render(component_name, props, prerender_options)` to return a string of JavaScript to execute _after_ calling `React.render` Any subclass of `ExecJSRenderer` may use those hooks (for example, `SprocketsRenderer` uses them to handle `console.*` on the server). ### Custom View Helper `react-rails` uses a "helper implementation" class to generate the output of the `react_component` helper. The helper is initialized once per request and used for each `react_component` call during that request. You can provide a custom helper class to `config.react.view_helper_implementation`. The class must implement: - `#react_component(name, props = {}, options = {}, &block)` to return a string to inject into the Rails view - `#setup(controller_instance)`, called when the helper is initialized at the start of the request - `#teardown(controller_instance)`, called at the end of the request `react-rails` provides one implementation, `React::Rails::ComponentMount`. ### Custom JSX Transformer `react-rails` uses a transformer class to transform JSX for the browser. The transformer is initialized once, at boot. You can provide a custom transformer to `config.react.jsx_transformer_class`. The transformer must implement: - `#initialize(options)`, where options is the value passed to `config.react.jsx_transform_options` - `#transform(code_string)` to return a string of transformed code `react-rails` provides two transformers, `React::JSX::JSXTransformer` and `React::JSX::BabelTransformer`.