javascript_response_obj_example.js

// example of response with errors                                                                                                                                  
var respObjWithErrors = {
  errors: [{
      key: 'could.not.insert',
      msg: "couldn't insert new usr into db"
  }],
  data:  { /* some data goes here */}
};

var respObj = { errors:[], data:{/* some data goes here */} }
someAlreadyDefinedCallback(respObj);

/* some controller function that gets passed as 
   a callback to a database query function  */
var someControllerFunction = function(respObj) {
  var errorMessagesArr = [];
  if (respObj.errors.length > 0){
    for(var i=0; i<respObj.errors.length; i++) {
      errorMessagesArr.push(respObj.errors[i].msg);
    }
    
    resp.send(errorMessagesArr.join("\n"));
  }
  else {
    resp.send(respObj.data);
  }
};