gistfile1.js

// DAO
function create(obj, callback) {
  var Model = this;
  var ctx = new EventEmitter();
  ctx.data = obj;
  ctx.callback = callback;
  
  
  Model.emit('create:start', ctx);
  
  
  this._adapter.create(obj, function(err, result) {
    ctx.result = result;
    ctx.emit('finished');
    Model.emit('create:finish', ctx);
    callback(err, result);
  });
}

// hook usage
MyModel.on('create:start', function(ctx) {
  var start = Date.now();
  console.log(ctx.data); // => {...}
  ctx.once('finished', function() {
    console.log('it took %s ms', Date.now() - start);
  });
});