This is broken for me on load. I think the problem is that it falsely assumes that the HTML element exists before the code in the cell gets executed: if I force it to re-execute after the page has loaded then it will work.

Yeah, it's looking broken on load for me too. Open to pull requests if you have a fix!

Thanks for your pull request! Looks like it worked a treat :)

I have a question: I tried to use canvas.strokeText() and canvas.fillText() but they don't seem to be available.