[ReactJS] basic countdown mechanics (https://gist.github.com/srph/fcd27d3e87a483b26ee9)

CountdownControl.js

var CountdownControl = React.createClass({
  // Simplified for brevity
  
  render: function() {
    var control = this.props.status
      ? 'Pause'
      : 'Resume';
      
    return (
      <span onClick={this._handleClick}>
        {control} |
      </span>
    );
  },
  _handleClick: function() {
    // Toggle interval (clear or set) based on this.props.status
  }
});

CountdownTimer.js

var CountdownTimer = React.createClass({
  // Simplified for brevity
  _setInterval: function() {
    /* this.interval = setInterval....
     * call setTick as callback for setInterval 
     */
  },
  _clearInterval: function() { /* this.interval = clearInterval.. */ },
  
  _setTick: function() { /* run tick */ },
  
  render: function() {
    return (
      <CountdownControl
        status={this.interval}
        pause={this._setInterval}
        resume={this._clearInterval} />
      {this.state.elapsed} seconds has elapsed
    );
  }
});