On 08.01.2014 00:30, Jared Zimmerman wrote:

I think their might be some misunderstanding as to what I'm proposing, my suggestion is that is is literally impossible to type a user name that is incompatible with our system, there would be no before and after, there would be no submit and then show a different user name, as the user types in the input field only acceptable characters and formats are accepted, characters that aren't allowed either don't show up and all or are automatically replaced as the user types, if they type i as the first character I is shown instead. there is not "error" step in the process.

I understand your proposal, but I disagree with the concept of an input field that literally doesn't allow the user to type in an invalid username.

I don't think replacing seemingly random characters as the user types them would make for a very good user experience. The same goes for not showing invalid characters at all. An input field that for no apparent reason doesn't behave the way people are used to would in my opinion frustrate people, rather than helping them out.

Imho, we should instead show a little tooltip or something next to the input field that tells the user if certain characters are invalid. (This is a quite common pattern that most users should be familiar with). As you rightly pointed out though, an 'error' step should be avoided. Therefore, i suggest making the submit button unclickable until any invalid characters in the input field are replaced by the user.

I've made a little demo to make my concept a little clearer: http://cdpn.io/urwJf (Try entering an underscore in the 'username field')

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best, max. @awesomephant