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Rails: Radio Buttons In Nested Forms

Yechiel Kalmenson on September 12, 2017

The story behind my first Stack Overflow answer. I was recently asked to add a feature to a Rails app. The app is a Contact Management S...

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Bert Bruynooghe • Sep 13 '17

FYI: you can write <%= radio_button_tag "contact[default_telephone]" %> as <%= radio_button_tag :contact, index: :default_telephone %>, which leads to same name, but it feels a bit more 'railsy'.

Yechiel Kalmenson • Sep 14 '17 • Edited

I'm not seeing that.

According to the documentation the second argument passed to radio_button_tag is the value of the input. Writing the tag the way you did gives me a radio button that looks like this:

<input type="radio" name="contact" id="contact__:index__:default_telephone_" value="{:index=>:default_telephone}">

I tried a few other variations and none gave e a properly formatted radio button.

Bert Bruynooghe • Sep 14 '17

Sorry, I was a bit quick to reply:

<%= f.radio_button :default_telephone_index, phone_form.index %>

should give you what you want, considering you have to have accessors for default_telephone_index on you model/form_object. (Which would be a good approach anyway, since you want as little code as possible in your view.) Also note that the radio_button is on the overall form, not the phoneNumber formbuilder.

Also, the original intent of my comment was to point you to the use of the :index option not to have to compose names yourself, but it only works on methods like radio_button on the formbuilder, not on _tag methods.