cheatsheets/react@0.14.md

432 lines
9.9 KiB
Markdown

---
title: React.js (v0.14)
category: React
deprecated: true
intro: |
**Deprecated:** this guide targets an old version of React (v0.14). See the [updated React cheatsheet](react) for new versions.
---
{%raw%}
### Components
```js
var Component = React.createClass({
render: function () {
return <div>Hello {this.props.name}</div>;
}
});
```
```js
ReactDOM.render(<Component name="John" />, document.body);
```
{:.light}
Use the [React.js jsfiddle](http://jsfiddle.net/reactjs/69z2wepo/) to start hacking. (or the unofficial [jsbin](http://jsbin.com/yafixat/edit?js,output))
### Nesting
```js
var UserAvatar = React.createClass({...});
var UserProfile = React.createClass({...});
```
{:.light}
```js
var Info = React.createClass({
render() {
return <div>
<UserAvatar src={this.props.avatar} />
<UserProfile username={this.props.username} />
</div>;
}
});
```
Nest components to separate concerns. See [multiple components](http://facebook.github.io/react/docs/multiple-components.html).
## States & Properties
{:.center}
### States and props
```html
<MyComponent fullscreen={true} />
```
{:.light}
```js
// props
this.props.fullscreen //=> true
// state
this.setState({ username: 'rstacruz' });
this.replaceState({ ... });
this.state.username //=> 'rstacruz'
```
```js
render: function () {
return <div className={this.props.fullscreen ? 'full' : ''}>
Welcome, {this.state.username}
</div>;
}
```
Use [props](https://facebook.github.io/react/docs/tutorial.html#using-props) (`this.props`) to access parameters passed from the parent.
Use [states](https://facebook.github.io/react/docs/tutorial.html#reactive-state) (`this.state`) to manage dynamic data.
### Setting defaults
```js
React.createClass({
getInitialState: function () {
return { comments: [] };
},
getDefaultProps: function () {
return { name: "Hello" };
}
);
```
Pre-populates `this.state.comments` and `this.props.name`.
## Components
### Component API
```js
ReactDOM.findDOMNode(c) // 0.14+
React.findDOMNode(c) // 0.13
c.getDOMNode() // 0.12 below
```
{:.light}
```js
c.forceUpdate()
c.isMounted()
c.state
c.props
c.setState({ ... })
c.replaceState({ ... })
c.setProps({ ... }) // for deprecation
c.replaceProps({ ... }) // for deprecation
c.refs
```
These are methods available for `Component` instances. See [Component API](http://facebook.github.io/react/docs/component-api.html).
### Component specs
| Method | What |
| ---- | ---- |
| [`render()`](http://facebook.github.io/react/docs/component-specs.html#render) | |
| ---- | ---- |
| [`getInitialState()`](http://facebook.github.io/react/docs/component-specs.html#getinitialstate) | |
| [`getDefaultProps()`](http://facebook.github.io/react/docs/component-specs.html#getdefaultprops) | |
| ---- | ---- |
| [`mixins: [ ... ]`](http://facebook.github.io/react/docs/component-specs.html#mixins) | Mixins ... [more](#mixins) |
| [`propTypes: { ... }`](http://facebook.github.io/react/docs/component-specs.html#proptypes) | Validation ... [more](#property-validation) |
| [`statics: { ... }`](http://facebook.github.io/react/docs/component-specs.html#statics) | Static methods |
| [`displayName: "..."`](http://facebook.github.io/react/docs/component-specs.html#displayname) | Automatically filled by JSX |
{:.greycode.no-head}
Methods and properties you can override. See [component specs](http://facebook.github.io/react/docs/component-specs.html).
## Lifecycle
### Mounting
| `componentWillMount()` | Before rendering (no DOM yet) |
| `componentDidMount()` | After rendering |
{:.greycode.no-head.lc}
Before initial rendering occurs. Add your DOM stuff on didMount (events, timers, etc). See [reference](http://facebook.github.io/react/docs/component-specs.html#mounting-componentwillmount).
### Updating
| `componentWillReceiveProps`*(newProps={})* | Use `setState()` here |
| `shouldComponentUpdate`*(newProps={}, newState={})* | Skips `render()` if returns false |
| `componentWillUpdate`*(newProps={}, newState={})* | Can't use `setState()` here |
| `componentDidUpdate`*(prevProps={}, prevState={})* | Operate on the DOM here |
{:.greycode.no-head.lc}
Called when parents change properties and `.setState()`. These are not called for initial renders. See [reference](http://facebook.github.io/react/docs/component-specs.html#updating-componentwillreceiveprops).
### Unmounting
| `componentWillUnmount()` | Invoked before DOM removal |
{:.greycode.no-head.lc}
Clear your DOM stuff here (probably done on didMount). See [reference](http://facebook.github.io/react/docs/component-specs.html#unmounting-componentwillunmount).
## Examples
### Example: loading data
```js
React.createClass({
componentDidMount: function () {
$.get(this.props.url, function (data) {
this.setState(data);
}.bind(this));
},
render: function () {
return <CommentList data={this.state.data} />
}
});
```
See [initial AJAX data](http://facebook.github.io/react/tips/initial-ajax.html).
## DOM nodes
### References
```html
<input ref="myInput">
```
{:.light}
```js
this.refs.myInput
ReactDOM.findDOMNode(this.refs.myInput).focus()
ReactDOM.findDOMNode(this.refs.myInput).value
```
### DOM Events
Add attributes like `onChange`. See [events](https://facebook.github.io/react/docs/events.html).
```html
<input type="text"
value={this.state.value}
onChange={this.handleChange} />
```
{:.light}
```js
handleChange: function(event) {
this.setState({ value: event.target.value });
}
```
Allows access to DOM nodes. See [References](http://facebook.github.io/react/docs/more-about-refs.html).
### Two-way binding
```html
Email: <input type="text" valueLink={this.linkState('email')} />
```
{:.light}
```js
React.createClass({
mixins: [React.addons.LinkedStateMixin]
});
```
```js
this.state.email
```
Use [LinkedStateMixin](http://facebook.github.io/react/docs/two-way-binding-helpers.html) for easier two-way binding.
## Property validation
### Basic types
```js
React.createClass({
propTypes: {
email: React.PropTypes.string,
seats: React.PropTypes.number,
settings: React.PropTypes.object,
callback: React.PropTypes.func,
isClosed: React.PropTypes.bool,
any: React.PropTypes.any,
}
});
```
Primitive types: `.string`, `.number`, `.func`, and `.bool`. See [propTypes](http://facebook.github.io/react/docs/reusable-components.html#prop-validation).
### Required types
```js
propTypes: {
requiredFunc: React.PropTypes.func.isRequired,
requiredAny: React.PropTypes.any.isRequired,
```
Add `.isRequired`.
### React elements
```js
propTypes: {
element: React.PropTypes.element, // react element
node: React.PropTypes.node, // num, string, element
// ...or array of those
```
Use `.element`, `.node`.
### Enumerables
```
propTypes: {
enum: React.PropTypes.oneOf(['M','F']), // enum
union: React.PropTypes.oneOfType([ // any
React.PropTypes.string,
React.PropTypes.number ]),
```
Use `.oneOf`, `.oneOfType`.
### Arrays and objects
```js
propTypes: {
array: React.PropTypes.array,
arrayOf: React.PropTypes.arrayOf(React.PropTypes.number),
object: React.PropTypes.object,
objectOf: React.PropTypes.objectOf(React.PropTypes.number),
message: React.PropTypes.instanceOf(Message),
object2: React.PropTypes.shape({
color: React.PropTypes.string,
size: React.PropTypes.number
}),
```
Use `.array[Of]`, `.object[Of]`, `.instanceOf`, `.shape`.
### Custom validation
```js
propTypes: {
customProp: function(props, propName, componentName) {
if (!/matchme/.test(props[propName])) {
return new Error('Validation failed!');
}
}
}
```
Supply your own function.
## Other features
### Class set
```js
var cx = require('classnames');
render: function() {
var classes = cx({
'message': true,
'message-important': this.props.isImportant,
'message-read': this.props.isRead
});
return <div className={classes}>Great Scott!</div>;
}
```
Manipulate DOM classes with [classnames](https://www.npmjs.org/package/classnames), previously known as `React.addons.classSet`. See [Class set](http://facebook.github.io/react/docs/class-name-manipulation.html).
### Propagating properties
```html
<VideoPlayer src="video.mp4" />
```
{:.light}
```js
var VideoPlayer = React.createClass({
render: function() {
/* propagates src="..." down to this sub component */
return <VideoEmbed {...this.props} controls='false' />;
}
});
```
See [Transferring props](http://facebook.github.io/react/docs/transferring-props.html).
### Mixins
```js
var SetIntervalMixin = {
componentWillMount: function() { .. }
}
```
{:.light}
```js
var TickTock = React.createClass({
mixins: [SetIntervalMixin]
}
```
See [addons](https://facebook.github.io/react/docs/addons.html) for some built-in mixins.
## [Top level API](https://facebook.github.io/react/docs/top-level-api.html)
```js
React.createClass({ ... })
React.isValidElement(c)
ReactDOM.findDOMNode(c) // 0.14+
ReactDOM.render(<Component />, domnode, [callback]) // 0.14+
ReactDOM.unmountComponentAtNode(domnode) // 0.14+
ReactDOMServer.renderToString(<Component />) // 0.14+
ReactDOMServer.renderToStaticMarkup(<Component />) // 0.14+
```
## JSX patterns
### Style shorthand
```js
var style = { backgroundImage: 'url(x.jpg)', height: 10 };
return <div style={style}></div>;
```
See [inline styles](https://facebook.github.io/react/tips/inline-styles.html).
### InnerHTML
```js
function markdownify() { return "<p>...</p>"; }
<div dangerouslySetInnerHTML={{__html: markdownify()}} />
```
See [dangerously set innerHTML](https://facebook.github.io/react/tips/dangerously-set-inner-html.html).
### Lists
```js
var TodoList = React.createClass({
render: function() {
function item(itemText) {
return <li>{itemText}</li>;
};
return <ul>{this.props.items.map(item)}</ul>;
}
});
```
## See also
* [Animations](http://facebook.github.io/react/docs/animation.html)
{%endraw%}