gistfile1.js

var datasource = new Y.DataSource.IO({ source: ... });
datasource.on('data', function (e) {
  var raw = Y.JSON.parse(e.data),
      data = [],
      key;
  
  for (key in raw.pathToDataObject) {
    if (raw.pathToDataObject[key]) {
      data.push(raw.pathToDataObject[key]);
    }
  }
  
  e.data = data; // or e.pathToObject = data
});