plataformatec/simple_form — pull request #657 by ootoovak (2012-09-05 10:18:26+00:00)
Title: Adds an override to simple_form default classes.

There was a use case where I was using Twitter Bootstrap and wanted it to default to using `.form-horizontal` most of the time so I put set `config.form_class = 'simple_form form-horizontal'`. There were odd occasions where I didn't wan't this class set though, so I have added a mechanism where by you can use `:only_class` instead of `:class` in `simple_form_for` and it will completely replace any default classes.