Modal.js

## Modal.js
/**
 * Copyright 2004-present Facebook. All Rights Reserved.
 *
 * @providesModule RKModal
 * @flow
 */
'use strict';

var Portal = require('Portal');
var React = require('React');
var ReactChildren = require('ReactChildren');
var StyleSheet = require('StyleSheet');
var TouchableWithoutFeedback = require('TouchableWithoutFeedback');
var View = require('View');

/**
 * Displays given contents on top of everything else in the application UI.
 *
 * The `isOpen` property determines whether to show or hide the modal.
 *
 * ```
 * return (
 *   <Modal
 *     onRequestClose={() => this.setState({ isModalOpen: false })}
 *     isOpen={this.state.isModalOpen}>
 *     <View ...
 *   </Modal>
 * );
 * ```
 */
var Modal = React.createClass({

  _tag: '',

  propTypes: {
    /**
     * The contents of the modal
     */
    children: React.PropTypes.any,

    /**
     * If true, the modal will be rendered
     */
    isOpen: React.PropTypes.bool.isRequired,

    /**
     * Style applied to the immediate wrapper of inner content.
     */
     contentContainerStyle: View.propTypes.style,

    /**
     * Style of the overlay view covering the whole screen.
     * It is transparent by default.
     */
    fullscreenContainerStyle: View.propTypes.style,

    /**
     * Called when the area anywhere outside the contents is tapped
     */
    onRequestClose: React.PropTypes.func,
  },

  getDefaultProps: function(): Object {
    return {
      isOpen: false,
    };
  },

  componentWillMount: function() {
    this._tag = Portal.allocateTag();
    if (this.props.isOpen) {
      Portal.showModal(this._tag, this._createModal(this.props));
    }
  },

  componentWillUnmount: function() {
    Portal.closeModal(this._tag);
  },

  componentWillReceiveProps: function(newProps: Object) {
    if (newProps.isOpen) {
      // Even if already shown, showModal will re-render
      // which is useful for updating the modal.
      Portal.showModal(this._tag, this._createModal(newProps));
    } else {
      Portal.closeModal(this._tag);
    }
  },

  _createModal: function(newProps: Object) {
    var fullscreenContainerStyles = [
      styles.fullscreenContainer,
      this.props.fullscreenContainerStyle,
    ];
    var children = newProps.children;
    // If there are multiple children we need to wrap them in a View.
    // This is because Touchable needs a single child.
    var hasMultipleChildren = ReactChildren.count(children) > 1;
    var content = hasMultipleChildren ?
      <View style={this.props.contentContainerStyle}>
        {children}
      </View> :
      children;
    return (
      <TouchableWithoutFeedback key={this._tag} onPress={this.props.onRequestClose}>
        <View style={fullscreenContainerStyles}>
          <TouchableWithoutFeedback>
            {content}
          </TouchableWithoutFeedback>
        </View>
      </TouchableWithoutFeedback>
    );
  },

  render: function(): any {
    return null;
  }
});

var styles = StyleSheet.create({
  fullscreenContainer: {
    position: 'absolute',
    left: 0,
    top: 0,
    right: 0,
    bottom: 0,
  },
});

module.exports = Modal;