Distinguish LTI Deep Linking requests coming from different RCEs

[RuslanDauhiala]

I'm using editor_button placement to embed some text into a Rich Content Editor via LTI Deep Linking.

Is there any way to distinguish LTI Deep Linking requests coming from different RCEs?

Like, I want to know if I get a request from course outcome's RCE VS course discussion's RCE.

[chriscas]

Hi @RuslanDauhiala,

As a Canvas admin, I checked out a few RCE deep link launches for tools we have installed in our instance.  From what I can see, there is nothing to distinguish which internal Canvas area the user is in.  I also took a quick look through available LTI Variable Substitutions for custom launch parameters, but don't see anything there to fit your needs either.

Someone else may have some different or advanced info, but I wanted to at least get you an initial reply for now.

-Chris

[RuslanDauhiala]

Thank you for your response @chriscas! I've done some research before posting my question here and saw that LTI requests look identical 2 RCEs located in different areas (course outcomes and course discussions). I was wondering if I missed something.

Thanks again!

[matthew_buckett]

I haven't seen anything either.

On approach to address this is to add a postMessage handler to the Canvas theme that responds to custom messages from the LTI and depending on the Canvas page (eg either by parsing the URL or extracting something out of the content of the page) responds differently. Then when the LTI launches it sends a cross frame message and gets response indicating what type of page the user is currently on. Similar to how the existing Canvas postMessage calls are handles.

This wouldn't be cross platform (eg wouldn't work in Moodle) and is a bit of a hack, but it would probably work (assuming the existing Canvas postMessage handlers don't get in the way of the theme based ones).