cheatsheets/react.md

title	layout
React.js	default

Basic class

React.createClass({
  render: function () {
    return (
      <div>Hello {this.props.name}</div>
    );
  }
});

Using components

var Component = React.createClass({ ... });

var compo = React.render(<Component />, mountnode);

States

this.setState({ editing: true });
this.state.editing === true

this.replaceState({ ... });

Properties

this.setProps({ fullscreen: true });
this.props.fullscreen === true

this.replaceProps({ ... });

API

c.getDOMNode() // deprecated 0.13
React.findDOMNode(c) // 0.13+

c.forceUpdate()
c.isMounted()

Methods

{
  render: function()
  getInitialState: function()
  getDefaultProps: function()
  mixins: []
  propTypes: {}       /* for validation */
  statics: { .. }     /* static methods */
  displayName: '..'   /* automatically filled in by jsx */
}

Lifecycle

componentWillMount()
componentDidMount()

// not on initial render
componentWillReceiveProps(props)
shouldComponentUpdate(props, state)
componentWillUpdate(props, state)
componentDidUpdate(prevProps, prevState)

componentWillUnmount()

// ...there is no DidUnmount or ReceiveState.

Initial states

React.createClass({
  getInitialState: function () {
    return {data: []};
  },

  render: function () {
    return (
      <CommentList data={this.state.data} />
    );
  }
});

Default properties

React.createClass({
  getDefaultProps: function () {
    return {name: ''};
  }
);

Before rendering

React.createClass({
  componentWillMount: function () {
    $.get(this.props.url, function (data) {
      this.setState(data);
    });
  },

  render: function () {
    return (
      <CommentList data={this.state.data} />
    );
  }
});

Actions

<form onSubmit={this.handleSubmit}>
  Name: <input ref="name">
</form>

React.createClass({
  handleSubmit: function (event) {
    name = this.refs['name'].getDOMNode().value;
    // see two-way binding below
  }
})

Two-way binding

React.createClass({
  mixins: [React.addons.LinkedStateMixin],
  getInitialState: function() {
    return {value: 'Hello!'};
  },
  render: function() {
    return <input type="text" valueLink={this.linkState('value')} />;
  }
});
// LinkedStateMixin adds a method to your React component called
// linkState(). 

Lists

var TodoList = React.createClass({
  render: function() {
    var createItem = function(itemText) {
      return <li>{itemText}</li>;
    };
    return <ul>{this.props.items.map(createItem)}</ul>;
  }
});

Property validation

React.createClass({
  propTypes: {
    // required
    requiredFunc: React.PropTypes.func.isRequired,
    requiredAny: React.PropTypes.any.isRequired,

    // primitives, optional by default
    bool: React.PropTypes.bool,
    func: React.PropTypes.func,
    number: React.PropTypes.number,
    string: React.PropTypes.string,
  }
});

Also:

  propTypes: {
    message: React.PropTypes.instanceOf(Message), // instanceof any Class
    element: React.PropTypes.element, // A React element
    enum: React.PropTypes.oneOf(['News', 'Photos']),
    node: React.PropTypes.node, // num, string, element, or array of these

    // any of below
    union: React.PropTypes.oneOfType([
      React.PropTypes.string,
      React.PropTypes.number
    ]),

    // arrays
    array: React.PropTypes.array,
    arrayOf: React.PropTypes.arrayOf(React.PropTypes.number),

    // objects
    object: React.PropTypes.object,
    objectOf: React.PropTypes.objectOf(React.PropTypes.number),

    // An object taking on a particular shape
    object2: React.PropTypes.shape({
      color: React.PropTypes.string,
      fontSize: React.PropTypes.number
    }),

    // custom validator
    customProp: function(props, propName, componentName) {
      if (!/matchme/.test(props[propName])) {
        return new Error('Validation failed!');
      }
    }
  }

Class set

render: function() {
  var cx = React.addons.classSet;
  var classes = cx({
    'message': true,
    'message-important': this.props.isImportant,
    'message-read': this.props.isRead
  });
  // same final string, but much cleaner
  return <div className={classes}>Great Scott!</div>;
}

Propagating properties to children

var VideoPlayer = React.createClass({
  render: function() {
    return <VideoEmbed {...this.props} controls='false' />;
  }
});

<VideoPlayer src="video.mp4" />

Mixins

var TickTock = React.createClass({
  mixins: [SetIntervalMixin]
}

SetIntervalMixin = {
  componentWillMount: function() { .. }
}

---

See also

• Animations