Parse.com trying to update user afterSave CloudCode

Question

I'm trying to use an afterSave function to update a field called accountBallance on a User object after something has been saved/updated to my Transactions object:

Parse.Cloud.afterSave("Transactions", function(request) {
  var amount = request.object.get("amount");
  var userId = request.object.get("user").id;
  console.log("Amount: " + amount);
  console.log("User: " + userId);


  Parse.Cloud.useMasterKey();
   var user = new Parse.User();
   var query = new Parse.Query(Parse.User);
   query.equalTo("objectId", userId);
   query.first({
      success: function(myObject) {
         var newBallance =  myObject.get("accountBallance") + amount;

         myObject.set("accountBallance", newBallance);
         myObject.save();

         // Set the job's success status
        response.success("User: " + userID + " Balance was updated with: " + amount);

      },
      error: function() {
         // Set the job's success status
        response.error("Couldn't update transaction!");
      }
   });


});

I'm getting the following error:

Result: TypeError: Cannot call method 'get' of undefined at query.first.success (main.js:22:38) at Parse.js:2:5786 at r (Parse.js:2:4981) at Parse.js:2:4531 at Array.forEach (native) at Object.w.each.w.forEach [as _arrayEach] (Parse.js:1:666) at n.extend.resolve (Parse.js:2:4482) at r (Parse.js:2:5117) at Parse.js:2:4531 at Array.forEach (native)

Any advice/help would be much appreciated.

Answer 1

It looks like the value returned from your query (myObject) is null. You should add a check for this:

if(myObject){
    // We are good!
}else{
    // user not found...maybe it was deleted?
}

Are you absolutely sure that the objectId printed here

console.log("User: " + userId);

Is in your user table?