Check for document.getElementById in main.js

[BrookeDot]

I use a slightly modified index.html page which includes my custom CSS styles and text changes. With the most recent update I ran into an issue with the index template where #url was undefined causing a fatal JavaScript error.

I tracked this down to document.getElementById("url").textContent = url; in main.js
https://github.com/bilde2910/Hauk/blob/master/frontend/main.js#L215

To keep things simple and to not make changes to main.js I just set the color of the URL div to match the background color which works. I think I could also use visibility:hidden instead

Overall, I do like the new changes providing more information but wondering if we should wrap some of the getElementById statements in a if type !== undefined) checks. If so, which ones?

The main one the effects the layout I've found is #URL so that's why I'm specifically mentioning that one.

[BrookeDot]

Default view:

Showing the URL is still there but hidden:

[bilde2910]

I can certainly implement this, as it's a pretty quick fix. Maybe it could be an idea to allow some kind of custom HTML setup, but right now I have no idea whatsoever on how to practically implement that.

[bilde2910]

Fixed in latest commit. Modifying the HTML isn't really officially supported, but at least you shouldn't get errors anymore when doing it