Question

I’ve got a Rails project which has a car model and it has multiple pictures. I’ve created a nested form so I can input the cars details and pictures all at the same time. I would like a radio button to select the picture to display in the gallery.

 %table
    = simple_form_for [@car] :html => {:multipart => true} do |f|
        = f.error_messages 
        = f.input :make
        = f.input :model
        = f.input :engine
        = f.input :price

        = f.simple_fields_for :car_pictures do |builder|
            .picture
                = builder.input :caption
                = builder.input :picture
                .thumb= image_tag builder.object.picture(:thumb)

        = f.button :submit

Is it possible to use a radio button in the ‘fields_for’ section to select the default/main picture? Or is there a better way?

Update

By putting the following under the fields_for all the radio buttons work independently, which is not what I want.

= builder.radio_button(:favourite, "test")

Each radio button is getting a unique name.

Update

What if I used the object_id as the value, how would I go about linking this in the create method?

= f.radio_button(:favourite_pic, builder.object_id)

Answer 1

Yes, your last guess was correct. I made a test application in which the customer can select a favorite photo: https://github.com/eicca/attrs_test (see commit changes marked by “added favorite example”).

There are two main points (according to your situation):

= f.radio_button(:favorite_pic_id, builder.object.id)

and

#models/car
has_one :favorite_pic, :class_name => "CarPicture"

And you need to add favorite_pic_id field to your cars table.