Our app is having an issue in IE where users inadvertently hitting backspace on non-text controls is causing navigation and issues. I've been tasked to suppress the backspace. But we're an app that is required to be 508 compliant. Accessibility is important. Wouldn't suppressing the backspace hurt our accessibility? And if so, Chrome and Edge don't have this issue. Do they not use the same keyboard shortcuts?
Alt + left arrow is standard in most newer browsers for the back button.
As this works in IE as well there is still a way for users to navigate back with their keyboard.
Technically this could be considered a fail as you are interfering with expected behaviour, but I personally think that the inconvenience of having a whole form disappear trumps that so if you decided to disable the backspace key if the currently selected input is empty that would be OK.
Make sure that this only stops normal backspace behaviour if an <input> is currently selected though (or <textarea>) using something like document.activeElement.
This way users can still use backspace to go back if they do not have an input selected.
One way that you can solve this without disabling the backspace button is with window.onbeforeunload;
Create a flag set to false that changes to true if any input has a value / changes are made etc.
Then use window.onbeforeunload and check the value of that flag. If it is true then show a message, false and return null so no warning is shown.
The following example should work all the way back to IE9 and fire a warning before allowing navigation.
I would encourage you to implement this anyway - it is just as easy to accidentally close the page, hit the physical back button etc. by mistake so doing this protects against all accidental navigation.
var changed = false; // change it to true if an input has a value / has changed.
window.onbeforeunload = function() {
return changed ? "Are you sure you want to navigate away? Unsaved changes will be lost." : null;
}