I\'ve been watching and reproducing these railscasts on my app: 196-nested-model-form-part-1 and 197-nested-model-form-part-2. I do not yet have a pro account so i can\'t watch
I don't have a pro account on Railscasts either, but sometimes it is a good idea to have a look at Ryan's Github account. Oftentimes he develops gems to stuff he covered in his episodes. There you will find this awesome nested_form gem, which does exactly what you want.
Of course you can reinvent the wheel, but I think it is much easier and faster to use Ryan's gem. The documentation explains perfectly how to use it. Have fun!
Did you know about remote links and forms? You can use a remote link here to accomplish what you want.
In your view:
link_to 'Add question', add_question_path(@survey), remote: true
In your controller
def add_question
@survey = Survey.find(params[:id])
respond_to do |format|
format.js #add_question.js.erb
end
end
The last step is to create a file app/views/surveys/add_question.js.erb
$('#my_survey').append('<%=j render partial: 'my_question_partial' %>')
Don't forget to create a route for your ask_question_path
For more info about remote links and forms see: http://tech.thereq.com/post/17243732577/rails-3-using-link-to-remote-true-with-jquery-ujs