Canvas Generated HTML Broken for External Tools

[sgilbert]

Starting yesterday, Canvas changed the HTML code that is generated for external tools. In my case, my Canvas class makes extensive use of Cay Horstmann's excellent CodeCheck tool. Prior to yesterday, the code generated by Canvas when inserting an external tool looked like this:

<iframe src="about:blank" name="tool_content" id="tool_content" 
       class="tool_launch" allowfullscreen="allowfullscreen" 
       webkitallowfullscreen="true" mozallowfullscreen="true" tabindex="0" 
       title="REX 9A" style="height:100%;width:100%;" 
       allow="geolocation *; microphone *; camera *; midi *; encrypted-media *; autoplay *; clipboard-write *; display-capture *" 
       data-lti-launch="true"><iframe>

If I save an assignment today, Canvas generates the same code, except, that the highlighted portion is changed to:

style="height:px;width:px;"

With no size or anything provided for the height or width. The effect is that all of our assignments now appear in a tiny window on the screen. (If I don't save or modify the assignments, they still work fine. If I click the Save button, they are overwritten with the new code.)

I'm hoping that someone who has the same problem, or someone who works for Canvas, or someone who has the ability to file a support ticket with Canvas) will raise this issue with support.

Thanks very much.

--Steve

[Zander254]

I have a set of assignments that use the external tool function to link to resources from the textbook website. These tools all worked a week ago. Today, I started getting an error message saying "couldn't find valid settings for this link" and the site returned me to my home page. When I entered the Edit function of an assignment to check the settings, nothing was out of the ordinary. I copied and pasted the URL for the external tool into a different tab to make sure it wasn't the textbook site - the site loaded properly.

[LucaHistan]

Hello, I also have the same problem and it bothers me a lot. I didn't notice this at the beginning of my work. I think maybe it's a platform maintenance issue. But if it was really the case, he would have warned us.

[sgilbert]

Hello.

Our Canvas Admins have filed a ticket but the response so far is not good. I've asked them to keep escalating the issue. In the event that your Canvas Admins want to intervein, it is case # 08702408.

--Steve

[ssadler · Accepted solution]

Thanks you for bringing this to our attention - it appears to have impacted several tool providers. The iframe height/width issue is on our team's radar. Our Engineering team has a potential fix which we're currently testing and hope to roll out soon.