LTI 1.3 Assignment associated with resource_link_id of another, can submit a score

[DigVargasDye]

Hello,

I am tracing my way through the Lines Items and Scores API to make sense of how to implement A&GP.

I can add a line item (which in turn creates a Canvas assignment) and can submit scores. Gravy.

However, when I create a new line item that lists ANOTHER line item as the resource_link_id, I see a success, but DO NOT see this in the UX at all. Where does this other line item "go" - is there a visual representation of it in the UX at all?

Relatedly - I am able to submit a score for this line item even though I cannot "see" it in Canvas. This score submission succeeds, but it does not populate anywhere (not in the Gradebook).

What is the value of `resource_link_id` on a line_item? What's the use case to associate two line items this way?

And what's the value in scores being submitted for these sub-line_items (if they are not in the gradebook)?

Should I be ignoring this `resource_link_id` param entirely and never submit it for line_item creation? 

Best,

.dig

[DigVargasDye · Accepted solution]

I may have just answered my own question. I am now seeing that if a user (admin/teacher in Canvas) creates an assignment within Canvas by selecting "External Tool" - the launch to the LTI tool includes a "resource_link_id":
```

"https://purl.imsglobal.org/spec/lti/claim/resource_link": {

   "id": "bb45b5fa-7fe3-4d3d-8f25-4810aaf59dbb",

   "description": "<p>The body content here</p>",

   "title": "Assignment #1 title",

   "validation_context": null,

   "errors": {

      "errors": {}

   }

},

```

And so now I can dynamically create a new assignment in MY system - and then any changes the user makes to the assignment within my LTI tool can be persisted back to Canvas with this reference.