I'm using the user registration add-on to create a new user and a new blog. I'm trying to put together a nice UI for the registration. Visit https://en.wordpress.com/signup/?new=gravitytest and look at the text input for the subdomain.
How could I go about setting up a subdomain or subdirectory input field? There's a few issues at hand.
1) How can I achieve the style of {text box}.domain.com or domain.com/{subdirectory}?
2) It doesn't appear that Gravity checks whether the subdomain/directory already exists. In the case that it already does, the site just isn't created. Bug?
2b) If Gravity does (or eventually does) check for the site name, could that be an AJAX option?