I'm currently looking to implement an LTI Advantage tool in Moodle and have some questions.
Regarding the LTI 1.3 core launch
As opposed to Canvas & Blackboard, the "https://purl.imsglobal.org/spec/lti/claim/lis > person_sourceid" claim sends an empty string and instead, the username is sent in "https://purl.imsglobal.org/spec/lti/claim/ext > user_username". Is this standard across all Moodle platforms and can I use this to detect which user has launched the tool?
Regarding the NRPS endpoint call
The NRPS endpoint call returns the user in the "user_id" format, which is not consistent with the core launch. I then configure custom parameters to send the username, and pass an rlid parameter to the endpoint (as per IMS Global specifications). Technically, the custom parameters should then be passed in the endpoint as well, should it not? In the NRPS endpoint, when passing the rlid parameter, a new "message" array appears, which means that Moodle has decided to support the rlid parameter, but the custom parameters are missing. Please see the image attached.
Your help would be greatly appreciated, thanks