“The caller does not have permission - google-apps-script”

Question

I am trying to create an extension to google classroom using google-apps-script but I seem to be running into permission problems- "the caller does not have permission". Can someone tell me why this is happening and what I need to do

I have tried accessing all the libraries provided by google cloud platform hoping that one of them gives the permission that is required all to no avail.

function listCourses() {
  var optionalArgs = {
    pageSize: 10
  };
  var response = Classroom.Courses.list(optionalArgs);
  var courses = response.courses;
  if (courses && courses.length > 0) {
    for (i = 0; i < courses.length; i++) {
      var course = courses[i];
      Logger.log('%s (%s)', course.name, course.id);
      var submissions = Classroom.Courses.CourseWork.list(course.id, optionalArgs);
      for (i = 0; i < submissions.length; i++) {
        var submission = submissions[i];
        Logger.log('%s', submission);
      }
    }
  } else {
    Logger.log('No courses found.');
  }
}

The code is meant to list out the course ids of courses in a particular class

Answer 1

This solution involves doing 2 things -

1. Updating the manifest file ( appsscript.json )
2. Updating the Code.gs file

Task 1

Updating the manifest file ( appsscript.json )

The appropriate Classroom API reference for this task is here .

Looks like even after enabling Advanced Google services... , you only get the following OAuth Scopes added -

• https://www.googleapis.com/auth/classroom.courses
• https://www.googleapis.com/auth/classroom.coursework.me.readonly
• https://www.googleapis.com/auth/classroom.profile.emails
• https://www.googleapis.com/auth/classroom.profile.photos
• https://www.googleapis.com/auth/classroom.rosters

You can view these by navigating to File > Project properties > Scopes .

However, when you try the API from the documentation link, under the Credentials > Google OAuth 2.0 tab, it shows 4 more, completely different OAuth scopes; those are as follows -

• https://www.googleapis.com/auth/classroom.coursework.me
• https://www.googleapis.com/auth/classroom.coursework.me.readonly
• https://www.googleapis.com/auth/classroom.coursework.students
• https://www.googleapis.com/auth/classroom.coursework.students.readonly

You need to add all 8 of these manually in your Apps Script manifest file. To do that, navigate to View & check the Show manifest file . There you need to add this code, perhaps below dependencies -

"oauthScopes": [
  "https://www.googleapis.com/auth/classroom.courses",
  "https://www.googleapis.com/auth/classroom.coursework.me.readonly",
  "https://www.googleapis.com/auth/classroom.profile.emails",
  "https://www.googleapis.com/auth/classroom.profile.photos",
  "https://www.googleapis.com/auth/classroom.rosters",

  "https://www.googleapis.com/auth/classroom.coursework.me",
  "https://www.googleapis.com/auth/classroom.coursework.me.readonly",
  "https://www.googleapis.com/auth/classroom.coursework.students",
  "https://www.googleapis.com/auth/classroom.coursework.students.readonly"
],

Note1: Only adding the newer 4 will not do the trick as the script would assume only these and not the original 5 that were auto-populated when your script ran for the first time.

Note2: The blank line is simply to differentiate between the scopes that get generated automatically vs. the ones you need to add manually (its redundant).

My appsscript.json file looks like this; yours might differ -

{
  "timeZone": "Asia/Kolkata",
  "dependencies": {
    "enabledAdvancedServices": [{
      "userSymbol": "Classroom",
      "serviceId": "classroom",
      "version": "v1"
    }]
  },
  "oauthScopes": [
    "https://www.googleapis.com/auth/classroom.courses",
    "https://www.googleapis.com/auth/classroom.coursework.me.readonly",
    "https://www.googleapis.com/auth/classroom.profile.emails",
    "https://www.googleapis.com/auth/classroom.profile.photos",
    "https://www.googleapis.com/auth/classroom.rosters",

    "https://www.googleapis.com/auth/classroom.coursework.me",
    "https://www.googleapis.com/auth/classroom.coursework.me.readonly",
    "https://www.googleapis.com/auth/classroom.coursework.students",
    "https://www.googleapis.com/auth/classroom.coursework.students.readonly"
  ],
  "exceptionLogging": "STACKDRIVER"
}

Task 2

Updating the Code.gs file

Once you have the right permissions, you're then free to play around with the actual code - the one you've originally shared lacks a few components and I've modified the same to get it working here -

function listCourses() {
  var optionalArgs = {
    pageSize: 10
  };
  var response = Classroom.Courses.list(optionalArgs);
  var courses = response.courses;
  if (courses && courses.length > 0) {
    for (var i = 0; i < courses.length; i++) {
      var course = courses[i];
      Logger.log('%s (%s)', course.name, course.id);
      var submissions = Classroom.Courses.CourseWork.list(course.id, optionalArgs);
      for (var j = 0; j < submissions.courseWork.length; j++) {
        var submission = submissions.courseWork[j];
        Logger.log('%s', submission);
      }
    }
  } else {
    Logger.log('No courses found.');
  }
}

Hope this helps:) but I don't actually know why these scopes are not added automatically, perhaps open up an issue with Google for it.

Edit note: Rectified grammatical errors