Value of ng-model becomes undefined on submit

[a-stankevich]

When input is inside a form and form is submitted, the value in the model becomes undefined.

On form submit code execution gets into parser at https://github.com/jstroem/ng-input-currency/blob/master/src/ng-input-currency.js#L75, and value is formatted currency string like '$10,000.00'. Next preformatValue doesn't expect this kind of string, neither does currency filter, so the function result is undefined.

Simply replacing preformatValue with toFloat seems to fixing the issue for me. But I don't get the idea behind preformatValue and it's not used anywhere else, so maybe there's a better fix for that.

I've put together a simple plunkr to reproduce this
https://next.plnkr.co/edit/8iRKPjGbhxiCrsPb