#+TITLE: React contribution layer for Spacemacs

[[file:img/react.png]]

* Table of Contents                                         :TOC_4_org:noexport:
 - [[Description][Description]]
   - [[Features][Features]]
 - [[Install][Install]]
 - [[Optional Configuration][Optional Configuration]]
 - [[Key Bindings][Key Bindings]]
   - [[js2-mode][js2-mode]]
   - [[Folding (js2-mode)][Folding (js2-mode)]]
   - [[Refactoring (js2-refactor)][Refactoring (js2-refactor)]]
   - [[Formatting (web-beautify)][Formatting (web-beautify)]]
     - [[Documentation (js-doc)][Documentation (js-doc)]]
   - [[Auto-complete and documentation (tern)][Auto-complete and documentation (tern)]]
   - [[JSON][JSON]]

* Description

ES6 and JSX ready configuration layer for React
It will automatically recognize =.jsx= and =.react.js= files

** Features
- on-the-fly syntax checking
- proper syntax highlight and indentation with jsx
- ternjs turbocharged autocompletion as in js2-mode
- jsfmt automatic formatting
- js2-refactor
- js-doc

* Install

To use this contribution add it to your =~/.spacemacs=

#+begin_src emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(react))
#+end_src

You will also need to install =tern= to use the auto-completion and
documentation features:
#+BEGIN_SRC sh
  $ npm install -g tern
#+END_SRC

To use the on-the-fly syntax checking, install =eslint= with babel and react support:
#+BEGIN_SRC sh
  $ npm install -g eslint babel-eslint eslint-plugin-react
#+END_SRC

If your project do not use a custom =.eslintrc= file I strongly advice you to try out this one by Airbnb:
[[https://github.com/airbnb/javascript/blob/master/linters/.eslintrc][.eslintrc]]

In order to use automatic code formatting you need to install ~js-beautify~ with:
#+BEGIN_SRC sh
  $ npm install -g js-beautify
#+END_SRC

Be sure to have the ~e4x~ option set to ~true~ on your ~.jsbeautifyrc~ here it is my configuration as an example:
#+BEGIN_SRC json
  {
    "indent_size": 2,
    "indent_char": " ",
    "eol": "\n",
    "indent_level": 0,
    "indent_with_tabs": false,
    "preserve_newlines": true,
    "max_preserve_newlines": 2,
    "jslint_happy": false,
    "space_after_anon_function": false,
    "brace_style": "collapse",
    "keep_array_indentation": false,
    "keep_function_indentation": false,
    "space_before_conditional": true,
    "break_chained_methods": true,
    "eval_code": false,
    "unescape_strings": false,
    "wrap_line_length": 80,
    "wrap_attributes": "auto",
    "wrap_attributes_indent_size": 2,
    "e4x": true,
    "end_with_newline": true
  }
#+END_SRC

* Optional Configuration

You may refer to the =web-mode= configuration for fine tuning the indenting behaviour.

For example to have a consistent 2 spaces indenting both on =js= and =jsx= you may use these settings:

#+begin_src emacs-lisp
  (setq-default
   ;; js2-mode
   js2-basic-offset 2
   ;; web-mode
   css-indent-offset 2
   web-mode-markup-indent-offset 2
   web-mode-css-indent-offset 2
   web-mode-code-indent-offset 2
   web-mode-attr-indent-offset 2)
#+end_src

And if you want to have 2 space indent also for element's attributes, concatenations and contiguous function calls:
#+begin_src emacs-lisp
  (with-eval-after-load 'web-mode
    (add-to-list 'web-mode-indentation-params '("lineup-args" . nil))
    (add-to-list 'web-mode-indentation-params '("lineup-concats" . nil))
    (add-to-list 'web-mode-indentation-params '("lineup-calls" . nil)))
#+end_src


* Key Bindings

** js2-mode

| Key Binding | Description                         |
|-------------+-------------------------------------|
| ~SPC m w~   | toggle js2-mode warnings and errors |

** Folding (js2-mode)

| Key Binding | Description              |
|-------------+--------------------------|
| ~SPC m z c~ | hide element             |
| ~SPC m z o~ | show element             |
| ~SPC m z r~ | show all element         |
| ~SPC m z e~ | toggle hide/show element |
| ~SPC m z F~ | toggle hide functions    |
| ~SPC m z C~ | toggle hide comments     |

** Refactoring (js2-refactor)

Bindings should match the plain emacs assignments.

| Key Binding   | Description                                                                                                    |
|---------------+----------------------------------------------------------------------------------------------------------------|
| ~SPC x m j~   | move line down, while keeping commas correctly placed                                                          |
| ~SPC x m k~   | move line up, while keeping commas correctly placed                                                            |
| ~SPC m k~     | deletes to the end of the line, but does not cross semantic boundaries                                         |
| ~SPC m r 3 i~ | converts ternary operator to if-statement                                                                      |
| ~SPC m r a g~ | creates a =/* global */= annotation if it is missing, and adds var to point to it                              |
| ~SPC m r a o~ | replaces arguments to a function call with an object literal of named arguments                                |
| ~SPC m r b a~ | moves the last child out of current function, if-statement, for-loop or while-loop                             |
| ~SPC m r c a~ | converts a multiline array to one line                                                                         |
| ~SPC m r c o~ | converts a multiline object literal to one line                                                                |
| ~SPC m r c u~ | converts a multiline function to one line (expecting semicolons as statement delimiters)                       |
| ~SPC m r e a~ | converts a one line array to multiline                                                                         |
| ~SPC m r e f~ | extracts the marked expressions into a new named function                                                      |
| ~SPC m r e m~ | extracts the marked expressions out into a new method in an object literal                                     |
| ~SPC m r e o~ | converts a one line object literal to multiline                                                                |
| ~SPC m r e u~ | converts a one line function to multiline (expecting semicolons as statement delimiters)                       |
| ~SPC m r e v~ | takes a marked expression and replaces it with a var                                                           |
| ~SPC m r i g~ | creates a shortcut for a marked global by injecting it in the wrapping immediately invoked function expression |
| ~SPC m r i p~ | changes the marked expression to a parameter in a local function                                               |
| ~SPC m r i v~ | replaces all instances of a variable with its initial value                                                    |
| ~SPC m r l p~ | changes a parameter to a local var in a local function                                                         |
| ~SPC m r l t~ | adds a console.log statement for what is at point (or region)                                                  |
| ~SPC m r r v~ | renames the variable on point and all occurrences in its lexical scope                                         |
| ~SPC m r s l~ | moves the next statement into current function, if-statement, for-loop, while-loop                             |
| ~SPC m r s s~ | splits a =String=                                                                                              |
| ~SPC m r s v~ | splits a =var= with multiple vars declared into several =var= statements                                       |
| ~SPC m r t f~ | toggle between function declaration and function expression                                                    |
| ~SPC m r u w~ | replaces the parent statement with the selected region                                                         |
| ~SPC m r v t~ | changes local =var a= to be =this.a= instead                                                                   |
| ~SPC m r w i~ | wraps the entire buffer in an immediately invoked function expression                                          |
| ~SPC m r w l~ | wraps the region in a for-loop                                                                                 |

** Formatting (web-beautify)

| Key Binding | Description                                                  |
|-------------+--------------------------------------------------------------|
| ~SPC m =~   | beautify code in js2-mode, json-mode, web-mode, and css-mode |

*** Documentation (js-doc)

You can check more [[https://github.com/mooz/js-doc/][here]]

| Key Binding   | Description                           |
|---------------+---------------------------------------|
| ~SPC m r d b~ | insert JSDoc comment for current file |
| ~SPC m r d f~ | insert JSDoc comment for function     |
| ~SPC m r d t~ | insert tag to comment                 |
| ~SPC m r d h~ | show list of available jsdoc tags     |

** Auto-complete and documentation (tern)

| Key Binding   | Description                                                                              |
|---------------+------------------------------------------------------------------------------------------|
| ~SPC m C-g~   | brings you back to last place you were when you pressed M-..                             |
| ~SPC m g g~   | jump to the definition of the thing under the cursor                                     |
| ~SPC m g G~   | jump to definition for the given name                                                    |
| ~SPC m h d~   | find docs of the thing under the cursor. Press again to open the associated URL (if any) |
| ~SPC m h t~   | find the type of the thing under the cursor                                              |
| ~SPC m r r V~ | rename variable under the cursor using tern                                              |

** JSON

| Key Binding | Description                        |
|-------------+------------------------------------|
| ~SPC m h p~ | Get the path of the value at point |