Basic Modal for react-native on Android

Modal.android.js

// Basic Android-implementation of Modal
//
// based on https://github.com/niftylettuce/react-native-loading-spinner-overlay

import React, {StyleSheet, View} from 'react-native';

const Portal = require('react-native/Libraries/Portal/Portal.js');

export default React.createClass({

  propTypes: {
    animated: React.PropTypes.bool,    // @todo support this
    onDismiss: React.PropTypes.func,
    transparent: React.PropTypes.bool, // @todo support this
    visible: React.PropTypes.bool
  },

  componentWillMount: function() {
    this.tag = Portal.allocateTag();
  },

  componentWillUnmount: function() {
    this.tag = null;
  },

  componentDidUpdate: function(prevProps) {
    if (!prevProps.visible && this.props.visible) {
      return Portal.showModal(this.tag, this.render());
    } else {
      Portal.closeModal(this.tag);
      if (this.props.onDismiss) {
        this.props.onDismiss();
      }
    }
  },

  render: function() {
    return (
      this.props.visible ?
        <View style={styles.container}>
          {this.props.children}
        </View>
        :
        null
    );
  }

});

const styles = StyleSheet.create({
  container: {
    backgroundColor: 'transparent',
    position: 'absolute',
    top: 0,
    bottom: 0,
    left: 0,
    right: 0
  }
});

Modal.ios.js

import {Modal} from 'react-native';
export default Modal;