twilio-recursive-callcenter.js

var data = [
  {}, // blank so we can index by 1 (matching the IDs)
  {id: 1, verb: 'Say', value: 'Thanks for calling. Press 1 to leave a voicemail or 2 Customer Service'
    options: {
      '1': 5, 
      '2': 6
    }
  },
  {id: 2, verb: 'Gather', children: [1]},
  {id: 3, verb: 'Say', value: 'Please leave a voicemail'}
  {id: 4, verb: 'Record'}
  {id: 5, multistep: true, children: [3, 4]},
  {id: 6, verb: 'Enqueue', value: 'CustomerServiceQueue'}
];

app.get('/twilio/incoming', handleIncoming);

function handleIncoming(req, res){
  var prev = req.params.previousStep;
  if( prev ){
    var digits = req.params.DIGITS; // Whatever they pressed on our previous prompt
    return handleSubsequent(prev, digits, req, res);
  }else{
    return handleFirstCall(req, res);
  }
}

function handleFirstCall(req, res){
  // send our first instruction, which is the gather
  // statement with a child "Say" command
  return res.send(200, toXml(data[2])); 
}

function handleSubsequent(prev, digits, req, res){
  var from = data[prev];
  var next = from.options[digits];
  return res.send(200, toXml(next));
}


function toXml(step){
  var xml;
  // whatever you do to generate XML. The key here is to make your gather steps point back to this url
  switch(step.verb){
    case 'Gather':
      var url = '/twilio/incoming?previousStep=' + step.id;
      xml = someGatherXmlVerb(url, step.children);
      break;
    
    // .. handle other verbs  
    
    default:
      throw new Error('Unhandled verb: ', step.verb);
  }
  
  return res.send(200, xml);
}