Grading for a student's assignment submission returns 400 Bad Request

[26-05-ins-111]

Please refer to this submission API - Submissions - Canvas LMS REST API Documentation

We observed "400 Bad Request" response status for some student's assignment submissions. Below is the request payload,

{submission[posted_grade]=[52]}

I would like to know reasons for "400 Bad Request" from above mentioned API. I couldn't find any reasons in the API documentation.

Appreciate your valuable feedbacks.

[robotcars]

A 400 generally means the request was OK but something you sent the API wasn't acceptable.

Not sure what language you're using but most libraries will allow the following:

- Return the full request URL to see if it's properly formatted request string.

- Return the request Response, and see if it details of the error.

You can also try formatting your request in the a browser's JavaScript Console and get the error details.

var submission = { posted_grade: 52 }
$.ajax({
     dataType: "json",
     url:'/api/v1/courses/123/assignments/456/submissions/789',
     data: {submission: submission},
}).done(function(r) {
     console.log(r)
}).error(function(r) {
     console.log(r.responseText)
})‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[stuart_ryan]

Hi 26-05-ins-111,

Robert is spot on, if you are happy to share some of the example request with us (sanitised of IDs of course) that would be really helpful so that we might be able to ascertain the cause.

If you have an example of a successful, and a failed request, that would be useful also.

Look forward to hearing from you!

Stuart

[26-05-ins-111]

Thanks for considering this.

Here is the example request,

PUT request to {Canvas-Institue-URL}/api/v1/courses/lti_context_id:{context_id}/assignments/{assignment_id}/submissions/lti_user_id:{user_id}

with a request payload - {submission[posted_grade]=[0]}

Since this was hard to figured out, we logged error response and saw that it is - "Student must be enrolled in the course as a student to be graded"

Any idea on how to recreate this issue in CanavsLMS?

[pklove]

If you do a /api/v1/users/lti_user_id:{user_id}/enrollments, does the student show as enrolled in the course with lti_context_id:{context_id}?

BTW, the payload does not look right.  If you are sending it as json, its probably more like

  { "submission" : { "posted_grade" : 0 }}

[26-05-ins-111]

Peter Love‌ This is our production and as developers, we don't have access to any of LMS course views that this error is happening.

Payload is accepting for all other assignment submissions except for some students. I think it shouldn't be a problem with the payload that we are sending.

Furthermore, we went though the Canvas code base at GitHub (https://github.com/instructure/canvas-lms) for this assignment submission route and could able to find below code snippets,

Snippet1

raise GradeError.new("Student is required") unless original_student

    unless context.includes_user?(original_student, context.admin_visible_student_enrollments) # allows inactive users to be graded

      raise GradeError.new("Student must be enrolled in the course as a student to be graded")

Snippet2

has_many :admin_visible_student_enrollments, -> { 

where("enrollments.workflow_state NOT IN ('rejected', 'completed', 'deleted') 

AND enrollments.type IN ('StudentEnrollment', 'StudentViewEnrollment')").preload(:user) }, class_name: 'Enrollment'

According to the above code snippets, it seems like it is checking a workflow state and enrollment type to return "400 - Bad request"

We tried to recreate this with development environment data but unfortunately, we couldn't able to recreate it.

Any idea on how to get any of 'rejected', 'completed', 'deleted' workflow states for a student and what are the enrollment types other than 'StudentEnrollment', 'StudentViewEnrollment'?

Stuart Ryan‌ Robert Carroll‌ Your thoughts also welcome.

[pklove]

If you have an API token for updating grades, I'd have thought you could call /api/v1/users/lti_user_id:{user_id}/enrollments

The reason to do this is to check that the student is enrolled and to see their enrolment state.  Some things will no work if they are concluded or inactive.  That is, they need to be active.  I haven't checked with updating grades, but it would be good to know the enrolment state of the users it fails on.

[robotcars]

Enrollment Dim - Canvas Data Portal

type	Enrollment type: TaEnrollment, DesignerEnrollment, StudentEnrollment, TeacherEnrollment, StudentViewEnrollment, ObserverEnrollment
workflow_state	Workflow state for enrollment: active, completed, rejected, deleted, invited, creation_pending

I verified this with the following queries in Canvas Data, but also found 'inactive' in workflow_state.

SELECT DISTINCT type FROM enrollment_dim;
SELECT DISTINCT workflow_state FROM enrollment_dim;

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