Error when trying to set Google Forms quiz score - google-apps-script

Question

I'm trying to change the grade of a response based on its answer.
Here's the code I'm using:
function myFunction() {
var form = FormApp.openById('formID123456');
// For a question with options: "1", "2", "3", and "4",
// award points for responses that correlate with their answers.
var formResponses = FormApp.getActiveForm().getResponses();
// Go through each form response
for (var i = 0; i < formResponses.length; i++) {
var response = formResponses[i];
var items = FormApp.getActiveForm().getItems();
// Assume it's the first item
var item = items[0];
var itemResponse = response.getGradableResponseForItem(item);
// Give 4 points for "4".
if (itemResponse != null && itemResponse.getResponse() == '4') {
var points = item.asScaleItem().getPoints();
itemResponse.setScore(points == 4);
}
// Give 3 points for "3".
else if (itemResponse != null && itemResponse.getResponse() == '3') {
var points = item.asScaleItem().getPoints();
itemResponse.setScore(points == 3);
}
// Give 2 points for "2".
else if (itemResponse != null && itemResponse.getResponse() == '2') {
var points = item.asScaleItem().getPoints();
itemResponse.setScore(points == 2);
}
// Give 1 points for "1".
else if (itemResponse != null && itemResponse.getResponse() == '1') {
var points = item.asScaleItem().getPoints();
itemResponse.setScore(points == 1);
// This saves the grade, but does not submit to Forms yet.
response.withItemGrade(itemResponse);
}
}
// Grades are actually submitted to Forms here.
FormApp.getActiveForm().submitGrades(formResponses);
}
This returns the error:
We're sorry, a server error occurred. Please wait a bit and try again. (line 23, file "Code")
It seemed like it was having issues changing the score of the response, but it didn't return a specific error, so I tried to isolate the part that changes the score.
Here, the script attempts only to change the score of the response.
function myFunction() {
var form = FormApp.openById('formID123456');
var formResponses = FormApp.getActiveForm().getResponses();
// Go through each form response
for (var i = 0; i < formResponses.length; i++) {
var response = formResponses[i];
var items = FormApp.getActiveForm().getItems();
// Assume it's the first item
var item = items[0];
var itemResponse = response.getGradableResponseForItem(item);
// Set Score to 3
var points = item.asScaleItem().getPoints();
itemResponse.setScore(points == 3);
}}
Again, it returned the same error, which confirms my suspicions. Why am I having this problem and how can I fix it? Any help would be much appreciated. Thanks!

Answer 1

As I mentioned in comments, your posted code erroneously uses a Boolean value in the call to ItemResponse#setScore, when the method expects to receive an Integer value.
Resolving the internal server error can be done by changing your entire if-elseif chain from this:
if (itemResponse != null && itemResponse.getResponse() == '4') {
var points = item.asScaleItem().getPoints();
itemResponse.setScore(points == 4); //<--- 'points == 4' evaluates to True or False
}
// Give 3 points for "3".
else if (...
to this:
// Skip changing the score if there was no answer or the answer is "falsey"
if (!itemResponse || !itemResponse.getResponse())
continue;
var answer = itemResponse.getResponse();
var newPoints = answer *1; // Convert "2" to 2, etc.
// Assumption: newPoints <= maximum possible points.
itemResponse.setScore(newPoints);
response.withItemGrade(itemResponse);
The below code is an example of how to set all graded items in all responses to a form to their maximum possible value.
function everyonePassesForTrying() {
var form = FormApp.getActiveForm();
var responses = form.getResponses();
responses.forEach(function (fr) {
fr.getGradableItemResponses().forEach(function (gr) {
if (gr.getResponse()) {
var maxPoints = getPointValue_(gr.getItem());
if (gr.getScore() !== maxPoints) {
// Re-grade the item's response.
gr.setScore(maxPoints);
// Update the form response with the new grade.
fr.withItemGrade(gr);
}
}
else { /* They didn't even try, so no change */ }
});
});
// Submit the altered scores.
form.submitGrades(responses);
}
var itemCache = {};
function getPointValue_(item) {
var id = item.getId();
// Use a pseudo-cache of the item's point values to avoid constantly determining what
// type it is, casting to that type, and getting the max points.
if(!itemCache[id]) {
// Haven't seen it yet, so cast and cache.
item = castToType_(item);
itemCache[id] = {maxPoints: item.getPoints() *1};
}
return itemCache[id].maxPoints;
}
function castToType_(item) {
// Cast the generic item to its type.
var CHECKBOX = FormApp.ItemType.CHECKBOX,
DATE = FormApp.ItemType.DATE,
DATETIME = FormApp.ItemType.DATETIME,
DURATION = FormApp.ItemType.DURATION,
LIST = FormApp.ItemType.LIST,
MULTICHOICE = FormApp.ItemType.MULTIPLE_CHOICE,
PARAGRAPH = FormApp.ItemType.PARAGRAPH_TEXT,
SCALE = FormApp.ItemType.SCALE,
TEXT = FormApp.ItemType.TEXT,
TIME = FormApp.ItemType.TIME;
switch (item.getType()) {
case CHECKBOX: item = item.asCheckboxItem();
break;
case DATE: item = item.asDateItem();
break;
case DATETIME: item = item.asDateTimeItem();
break;
case DURATION: item = item.asDurationItem();
break;
case LIST: item = item.asListItem();
break;
case MULTICHOICE: item = item.asMultipleChoiceItem();
break;
case PARAGRAPH: item = item.asParagraphTextItem();
break;
case SCALE: item = item.asScaleItem();
break;
case TEXT: item = item.asTextItem();
break;
case TIME: item = item.asTimeItem();
break;
default:
throw new Error("Unhandled gradable item type '" + item.getType() + "'");
break;
}
return item;
}