How do you use multiple form fields to interact with a single method in rails?

Question

I have a model which has start_at and end_at attributes. In the form for the end-user, I am displaying start_at using the standard datetime_select, but I'd rather not have a second datetime select presented to the user. I'm hoping I can create two fields that represent a duration; one for hours, the other for minutes. My question is, how in my view do I use form helpers to automatically fill in the fields when editing an existing entry. Furthermore, how would I connect that to the model and subsequently save the recording using the real attribute, end_at?

Thanks in advance for any advice you can give!

Answer 1

I have to do this a bunch and i've been doing the following:

1. Use the FormTagHelper versions of the calls for the field to be handled specially.
2. In the controller, read the form_tag values out of the params object.
3. delete the extra values:

    
    params[:examplemodelname].delete :distance if params[:examplemodelname].has_key? :distance

1. put the 'real' values into the params object (in your example, ends_at)
2. call ExampleModelName.new(params[:examplemodelname]) or @examplemodelname.update_attributes(params[:examplemodelname]) as per usual.