I\'m building an app, where users can give comments by just leaving their email to the comment.
I want them to be able to register directly from there, by a link wit
Yup, you got the right answer all by yourself! Formtastic's rdoc is a mess, but we're working on it. Another option if you want this purely at a view level is to use the :input_html
option, which gives you direct access to HTML attributes of the input tag:
f.input :email, :input_html => { :value => params[:email] }