Handling link validation errors

[daamsie]

I'm trying to provide some better feedback to the user when they have entered an incorrectly formatted URL. Currently if they enter a wrong url (eg. a url without http or https for example), it just doesn't do anything. There is no user feedback whatsoever, which can leave them wondering what they did wrong.

I'd like to catch this and show a message saying the url is invalidly formatted and that's why it's not inserting.

Any good way of doing this?