react

Airbnb React/JSX Style Guide

A mostly reasonable approach to React and JSX

Table of Contents

1. Basic Rules
2. Naming
3. Declaration
4. Alignment
5. Quotes
6. Spacing
7. Props
8. Parentheses
9. Tags
10. Methods
11. Ordering

Basic Rules

• Only include one React component per file.
• Always use JSX syntax.
• Do not use React.createElement unless you're initializing the app from a file that is not JSX.

Class vs React.createClass

• Use class extends React.Component unless you have a very good reason to use mixins.

// badconstListing=React.createClass({render(){return<div/>;}});// goodclassListingextendsReact.Component{render(){return<div/>;}}

Naming

• Extensions: Use .jsx extension for React components.

• Filename: Use PascalCase for filenames. E.g., ReservationCard.jsx.

• Reference Naming: Use PascalCase for React components and camelCase for their instances:

  // badconstreservationCard=require('./ReservationCard');// goodconstReservationCard=require('./ReservationCard');// badconstReservationItem=<ReservationCard/>;// goodconstreservationItem=<ReservationCard/>;

  Component Naming: Use the filename as the component name. For example, ReservationCard.jsx should have a reference name of ReservationCard. However, for root components of a directory, use index.jsx as the filename and use the directory name as the component name:

  // badconstFooter=require('./Footer/Footer.jsx')// badconstFooter=require('./Footer/index.jsx')// goodconstFooter=require('./Footer')

Declaration

• Do not use displayName for naming components. Instead, name the component by reference.

  // badexportdefaultReact.createClass({displayName: 'ReservationCard',// stuff goes here});// goodexportdefaultclassReservationCardextendsReact.Component{}

Alignment

• Follow these alignment styles for JSX syntax

  // bad<FoosuperLongParam="bar"anotherSuperLongParam="baz"/>// good<FoosuperLongParam="bar"anotherSuperLongParam="baz"/>// if props fit in one line then keep it on the same line<Foobar="bar"/>// children get indented normally<FoosuperLongParam="bar"anotherSuperLongParam="baz"><Spazz/></Foo>

Quotes

• Always use double quotes (") for JSX attributes, but single quotes for all other JS.

Why? JSX attributes can't contain escaped quotes, so double quotes make conjunctions like "don't" easier to type. Regular HTML attributes also typically use double quotes instead of single, so JSX attributes mirror this convention.

```javascript
// bad
<Foo bar='bar' />
// good
<Foo bar="bar" />
// bad
<Foo style={{ left: "20px" }} />
// good
<Foo style={{ left: '20px' }} />
```

Spacing

• Always include a single space in your self-closing tag.

  // bad<Foo/>// very bad<Foo/>// bad<Foo/>// good<Foo/>

Props

• Always use camelCase for prop names.

  // bad<FooUserName="hello"phone_number={12345678}/>// good<FoouserName="hello"phoneNumber={12345678}/>

Parentheses

• Wrap JSX tags in parentheses when they span more than one line:

  /// badrender(){return<MyComponentclassName="long body"foo="bar"><MyChild/></MyComponent>;}// goodrender(){return(<MyComponentclassName="long body"foo="bar"><MyChild/></MyComponent>);}// good, when single linerender(){constbody=<div>hello</div>;return<MyComponent>{body}</MyComponent>;}

Tags

• Always self-close tags that have no children.

  // bad<FooclassName="stuff"></Foo>// good<FooclassName="stuff"/>

• If your component has multi-line properties, close its tag on a new line.

  // bad<Foobar="bar"baz="baz"/>// good<Foobar="bar"baz="baz"/>

Methods

• Do not use underscore prefix for internal methods of a React component.

  // badReact.createClass({_onClickSubmit(){// do stuff}// other stuff});// goodclassextendsReact.Component{onClickSubmit(){// do stuff}// other stuff});

Ordering

• Ordering for class extends React.Component:

1. constructor
2. optional static methods
3. getChildContext
4. componentWillMount
5. componentDidMount
6. componentWillReceiveProps
7. shouldComponentUpdate
8. componentWillUpdate
9. componentDidUpdate
10. componentWillUnmount
11. clickHandlers or eventHandlers like onClickSubmit() or onChangeDescription()
12. getter methods for render like getSelectReason() or getFooterContent()
13. Optional render methods like renderNavigation() or renderProfilePicture()
14. render

• How to define propTypes, defaultProps, contextTypes, etc...

importReact,{Component,PropTypes}from'react';constpropTypes={id: PropTypes.number.isRequired,url: PropTypes.string.isRequired,text: PropTypes.string,};constdefaultProps={text: 'Hello World',};exportdefaultclassLinkextendsComponent{staticmethodsAreOk(){returntrue;}render(){return<ahref={this.props.url}data-id={this.props.id}>{this.props.text}</a>}}Link.propTypes=propTypes;Link.defaultProps=defaultProps;

• Ordering for React.createClass:

1. displayName
2. propTypes
3. contextTypes
4. childContextTypes
5. mixins
6. statics
7. defaultProps
8. getDefaultProps
9. getInitialState
10. getChildContext
11. componentWillMount
12. componentDidMount
13. componentWillReceiveProps
14. shouldComponentUpdate
15. componentWillUpdate
16. componentDidUpdate
17. componentWillUnmount
18. clickHandlers or eventHandlers like onClickSubmit() or onChangeDescription()
19. getter methods for render like getSelectReason() or getFooterContent()
20. Optional render methods like renderNavigation() or renderProfilePicture()
21. render

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