LTI 1.3 equivalent of ltiLaunchUrl

[hmoffatt]

We have our LTI tool integrated with Canvas and we support a review launch by sending a URL back in the ltiLaunchUrl field through the basic outcome service.

https://github.com/instructure/canvas-lms/blob/master/doc/api/assignment_tools.md#lti-launch-url

Is there an LTI 1.3 equivalent? I think it would be the submission review launch, but I don't think this is supported yet?

[terrygleason]

I found this:   (   https://www.imsglobal.org/sites/default/files/lti/LTIBasicOutcomesv1p1FinalRelease.pdf   )

3.5 Integration with LTI 1.3 ›

3.5.1 Claim for inclusion in messages The claim to include basic outcome parameters in LTI 1.3 messages is: https://purl.imsglobal.org/spec/lti-bo/claim/basicoutcome.

It contains two properties: lis_outcome_service_url and lis_result_sourcedid as dened above.

{ "lis_result_sourcedid": "82098-21uhd",

"lis_outcome_service_url": "https://www.myuniv.example.com/2344" }

Figure 10

[hmoffatt]

Thanks Terry but that is unfortunately not relevant.

In LTI 1.1 the basic outcome service is used to report grades and Canvas has extended this to support attaching a URL which can be used to launch a review.

In LTI 1.3 the basic outcome service is replaced by the assignments and grades service which doesn't have a direct equivalent of attaching a URL. It could be added as a line item in the grade submission potentially. There is also a separate submission review service which does this. Does Canvas have this or plan to?

[terrygleason]

Thank you for clarifying you are looking for an equivalent to attach a URL.  That might be easier for more users.

[karl · Accepted solution]

It's an extension on the score endpoint as part of the Assignment and Grades Service. More details are here: https://canvas.instructure.com/doc/api/file.assignment_tools.html and https://canvas.instructure.com/doc/api/score.html

Also, Canvas doesn't support submission review. We plan to add support for it, but do not have a committed timeline at the moment.

[hmoffatt]

Thanks Karl, that solves it.

Does Canvas behave the same as with LTI 1.1 in terms of matching up the tool for the LTI launch? For 1.1, my tool is at https://lti.myco.com/launch/app  , and my review links are https://lti.myco.com/launch/app?review=somedata   . Will this work?

On a related note, is the JSON format for loading developer keys (https://canvas.instructure.com/doc/api/file.lti_dev_key_config.html#config-in-canvas) an LTI standard or is that Canvas specific?

[hmoffatt]

To answer my own question, adding the custom claims on the score report with submission_type: basic_lti_launch and the extra data in the URL query string worked fine.

[hmoffatt]

@karlAlthough I had this working with a basic LTI launch, I'm now mixing it with deep linking and it's not working. Canvas says "Couldn't find valid settings for this link".

The setup is as follows:

• Content-selection tool registered as https://my.url/select
• Content selection returns target link URI of https://my.url/launch/content
• Tool launches and works correctly
• The review link reported to Assignments and Grades service is to https://my.url/launch/content?review=xyz
• Review launch fails with "Couldn't find valid settings for this link"

I have tried to make the links more consistent using just the query strings instead of changing the path, but this didn't help.

• Tool at https://my.url/select
• Target link URI https://my.url/select?content=abc
• Review link URI https://my.url/select?content=abc&review=xyz
• Tool works but review still fails to launch

My Canvas test install is a few months old so perhaps this has been fixed.

[hmoffatt]

Yes it works with an up to date Canvas install, but when using the query strings. It doesn't match a review link that is the same as a target link URI from content selection.

[matthew_buckett]

Is the line item service not going to work for you?

https://canvas.instructure.com/doc/api/line_items.html#method.lti/ims/line_items.create