Develop React in emacs in rjsx-mode

投稿日:2017年9月3日 更新日:


Hello everyone this is candle.
In this time I would like to introduce rjsx-mode of major-mode for react development of emacs.

The development of “react” has been tried and errored between emacs users, such as using web-mode or js2-jsx-mode of js2-mode.
Also I had been used js2-jsx-mode before rjsx-mode.

Since rjsx-mode is an extension of js2-mode, users of js2-mode can use it without discomfort.
rjsx-mode has auto complete function of jsx. it’s fantastic.


You use emacs
You use melpa or el-get

Installing rjsx-mode

You can install rjsx-mode from melpa or el-get.
I am using el-get, but I will explain both easily.

install with mepla

Lauch emacs and run ” M-x package-list-packages”

Emacs will display the melpa package index. You would search “rjsx-mode” with C-s

Move the cursor to rjsx-mode, type “i”, then type “x” to install.
You are asked whether you want to install it, you can install it by typing “y”.

Installation with melpa is over.

Install with el-get

It is easy to install rjsx-mode with el-get.
At first, you open the emacs conf file. I will open ~/.emacs.d/init.el file

write it.

(el-get-bundle rjsx-mode)

Reload init.el with “M-x eval-buffer and install rjsx-mode from el-get.

You can see that js2-mode is installed if you are looking at the progress.

It’s over.

rjsx-mode configuration

rjsx-mode automatically starts up in major mode for .jsx extension.
On the other hand, since it is not bind with .js extension, it will not launch in majar mode.
All files in which React JSX is written are not only .jsx extensions.
If you want to lauch the rjsx-mode for all of .js files, you set up like this.

(add-to-list 'auto-mode-alist '(".*\.js\'" . rjsx-mode))

As in the official website, if you run rjsx-mode only for the js file under the components or containers folder, do as this.

(add-to-list 'auto-mode-alist '("components\/.*\.js\'" . rjsx-mode))
(add-to-list 'auto-mode-alist '("containers\/.*\.js\'" . rjsx-mode))

Make the App.jsx file and check it good working.

touch App.jsx

Write this.

import React from 'react';

class App extends React.Component{
    this.state = {
      txt: 'this is the state text',


        <p>Text: {this.state.txt}</p>
        <input name="" type="text" onChange={this.update.bind(this)} />

export default App;

You can see that the majar mode is “RJSX”

Well, looking at the above image, warning is displayed because there is no semicolon at the end of the line.
I don’t sure it is from ES6, but the semicolon at the end of the line is no longer mandatory.
Disable this warning to edit configuration file and change to indent width to the 2 spaces.

open ~/.emacs.d/init.el file and write this.

(add-hook 'rjsx-mode-hook
          (lambda ()
            (setq indent-tabs-mode nil) ;;Use space instead of tab
            (setq js-indent-level 2) ;;space width is 2 (default is 4)
            (setq js2-strict-missing-semi-warning nil))) ;;disable the semicolon warning

It seems good.
The basic setting is over.

About JSX autocomplete

The rjsx mode does the autocomplete for jsx tags.
In jsx, typing “<” will automatically expand “/>”.

and enter “button”, delete “/” with “C-d”, the close button tag </button> is created.

It is really convenient


I think that React’s major mode will jostle with js2-jsx-mode, web-mode, rjsx-mode etc for a while.
Among them, I thought rjsx-mode was useful.


If you think this article is good, share it please



  1. Jon Rostran says:

    Hi Joppot. thank you very much for your post. It was very helpful. However, I should bring to your attention that the method to run rjsx-mode only on components/ or containers/ folder does not work.

    (add-to-list ‘auto-mode-alist ‘(“components\/.*\.js\'” . rjsx-mode)) ;; this does not work
    (add-to-list ‘auto-mode-alist ‘(“containers\/.*\.js\'” . rjsx-mode)) ;; this does not work

    The first method did work – running rjsx mode on all my .js files. Do you think you could help me run rjsx-mode only on components/ and containers/ folders? I would very much appreciate it. Thank you.

    • candle says:

      Hi, I’m sorry for the delay in sending feed back you.
      I checked it and yes surely it’s not working.
      So I improved to fix that problem. This configuration will be good working. Please try it.

      (add-to-list ‘auto-mode-alist ‘(“.*/components\\/.*\\.js\\'” . rjsx-mode))
      (add-to-list ‘auto-mode-alist ‘(“.*/containers\\/.*\\.js\\'” . rjsx-mode))


Your email address will not be published. Required fields are marked *


How to use f.lux, blue light cut software

Abstract Hello everyone. In this time I will explain how to use f.lux. f.flux can reduce the amount of blue light as much as possible. f.lux can adjust the blue light cut rate with the seek bar. Please try using it. Condition You use Mac or Windows I will explain it in Mac PC. Download f.lux Go to the blew site. Click the center “Download f.lux” button. Once you have downloaded the zip file, let’s double-click it and extract it. Since The executable file is expanded in the download folder, move it to the Application folder. It’s over. Use …

How to prevent preview from scrolling back to top in Atom’s Markdown

English 日本語 Abstract Hello everyone, it’s candle. Atom has a markdown preview function from the beginning. When markdown’s sentence becomes long, every time you edit it, the preview back to the top. And, you have to scroll every time to check. It is so tough, we will put a plug-in that will automatically adjust the preview. Premise Atom has been installed

Build flycheck + eslint environment supporting to react + es6 in Emacs.

Abstract Hello everyone it’s me candle. In this time let’s build emacs + eslint. There are many other syntax check packages such as jsHint, jsxHint, etc which check the coding rule of javascript. According to web info, these packages seem to be unable to adapt well with the latest javascript writing format such as React and es6. Nowadays eslint became to be mainstream. It has become used not only in emacs but also everywhere. I’m also emacs user, try it! I’m not a node JS and Elisp professional, it may contains useless writing or wrong writing. Please go easy on …

Import React components using Emacs and import-js2.2.0

Abstract Hello everybody it’s me candle. In this time we will import the component path with emacs and import-js. React recommends to write one component in one file, when development becomes to be big, the number of component increase. If you use 10 components with one Container, you need to write 10 import statements. import-js helps us from such troublesome work. Caution It worked well on the react web but in react native import-js didn’t successfully find out the component. Probably I think that there are some lack of the setting of import-js. Precondition Already exist React web environment I …

Build PlantUML environment on Mac using brew

Abstract Hello everybody it’s me candle. In this article, I would like to build a plantUML environment which can make UML easily on Mac. I have been used starUML for making UML. plantUML seems to be much more useful than that. Precondition You already use brew. Check java version I think that java is already installed in your mac pc. PlantUML can be run with mac default java. So you launch terminal app and check the java version with the below command. java -version Probably it can be work in java version around 1.8.x . Install graphviz graphviz is a …

I work in the venture company as a CTO. I start to write program in University, first I learned java, C++ and PHP. In the company, I'm developing web services by Rails. I do like to automation.