[ARCHIVED] Webwork LTI Issue

[steven_marshall]

Hi Everyone,

We have been working on setting up the Canvas LTI but are running into some issues. Canvas seems to pass information back to webwork when someone logs in but webwork does not do anything with it. I have checked the authen_LTI.conf over and over again, but can't find anything missing. I have had our Canvas admin double-check our password and the URL that is set in Canvas to ensure they match. I have ensured that the site.conf file has the correct "https" URL.

The error we receive is:

• The following path was reconstructed by WeBWorK. It should match the path in the LMS: at /opt/webwork/webwork2/lib/WeBWorK/Authen/LTIAdvanced.pm line 379.
• https://testdrive.cas.ou.edu/webwork2/casit_test5/ at /opt/webwork/webwork2/lib/WeBWorK/Authen/LTIAdvanced.pm line 380.
• OAuth verification failed. Check the Consumer Secret and that the URL in the LMS exactly matches the WeBWorK URL as defined in site.conf. E.G. Check that if you have https in the LMS url then you have https in $server_root_url in site.conf at /opt/webwork/webwork2/lib/WeBWorK/Authen/LTIAdvanced.pm line 417.

The site.conf URL info:

$webwork_url       = '/webwork2';
$server_root_url   = 'https://testdrive.cas.ou.edu'; 

So the URL that we have in Canvas is:

https://testdrive.cas.ou.edu/webwork2 

Anyone have a thought?

[James]

 @steven_marshall  

The error says there is a mismatch in the settings. I don't use WebWork (I'm going to use it this fall with a third party provider so that I don't have to set up the server), so I cannot comment directly about that. OAuth is not my area of expertise, so if this doesn't help, someone else may have an idea.

Here's what it looks like (all of these pathnames have your testdrive.cas.ou.edu) in front of them.

In Canvas, you're calling /webwork2 but webwork is expecting /webwork2/casit_test5.

For the redirect URI in Canvas, I would try /webwork2/casit_test5

There is probably more to that, though. People have been posting about the redirect URI needs to match exactly although the legacy redirect URI is more lenient. A comment in a GitHub issue talks about the need to match exactly. If your redirect URI is /webwork2 and it's getting called from /webwork2/casit_test5 then it won't match (unless you're using the legacy version). And if you're using /webwork2/casit_test5/login or /webwork2/casit_test5/refresh then you would need to include those in the redirect URI field as well.

Side note: Glad to see someone else is using CAS. I'm trying to upgrade ours from the version we installed in 2012 and the 6.1 documentation is some of the most difficult I've found to understand -- way harder than the Canvas documentation. Maybe if I had been living and breathing the CAS documentation for 7 years, I would understand it better like I do the Canvas stuff. I use CAS to get around our school not having an OAuth server. We use CAS to log into Canvas and I put my Wordpress site behind CAS in Apache and so I'm able to get my user information through CAS when the WordPress plugins didn't work.

[Adrienne_J_Gaut]

hi James - what is the 3rd party you are using for hosted WebWork and Canvas? thanks

[James]

@Adrienne_J_Gaut 

Sorry, I just saw this message. I went with Edfinity since it was recommended on the MAA website.

I'm glad I don't have to host WeBWorK myself, but my experience was rocky at the start. They said that their integration with Canvas works for hundreds of institutions with no problems, but I had to be the exception and they couldn't figure out why. The interface is simplistic and the site loads and responds fairly quickly. Some items are buried and you have to look up the help to figure out how to do stuff. They don't have a forward facing API that I can find -- I guess I've been spoiled by Canvas. There's a lot of clicking going on that I would write a program to automate if I had the API. Their tech support is really quick to respond to my questions, although it's normally not with an answer that I wanted.

I had never used WeBWorK before, so I don't know how much of this is WW and how much is Edfinity.

The grades do get passed back into Canvas as the students answer the questions, you don't have to wait until the assignment is over or make any requests to send the results, so that's nice. Given the trouble people were having here about getting WW to work as an LTI for Canvas and do grade passback, the limited time I had to set things up, and no available server to set things up on, I'm glad I went with them, but I have no one else to compare to.