SubmitButton.js

// src/components/SubmitButton.js
import React, { PropTypes } from 'react';
import RaisedButton from 'material-ui/lib/raised-button';

export default React.createClass({

  displayName: 'SubmitButton',

  propTypes: {
    label: PropTypes.string
  },

  contextTypes: {
    isFormValid: PropTypes.func.isRequired,
    submit: PropTypes.func.isRequired
  },

  getDefaultProps() {
    return {
      label: 'Submit'
    };
  },

  render() {
    return (
      <div>
        <RaisedButton
          primary
          disabled={!this.context.isFormValid()}
          label={this.props.label}
          onTouchTap={this.context.submit}/>
      </div>
    );
  }
});