ruby - Unique radio buttons when iterating in rails -

i'm creating application in have list of symptoms (@all_symptoms) on iterating , want have radio buttons each 1 indicating whether presence true or false. the problem keep running against no matter try radio buttons named same, can select true/false once on entire form.

i tried changing label to:

<%= ff.radio_button "presence_#{s.id}", true %> 

but there error because there (obviously) no method called "presence_x" symptoms. (for clarity: "presence" is attribute symptom, , accepts boolean value.)

the nested attribute part of form because part of appointment accepts attributes symptoms.

<%= f.fields_for :symptoms |ff| %>   <table>     <tr>       <th>name</th>       <th>presence</th>     </tr>      <% @all_symptoms.each |s| %>     <tr>       <td>         <%= s.name %>       </td>       <td>         <%= ff.label :presence, "true", :value => true %>         <%= ff.radio_button :presence, true, :value => true %>         <%= ff.label :presence, "false", :value => false %>         <%= ff.radio_button :presence, false, :value => false %>       </td>   </table> <% end %> 

have tried this?

<%= ff.radio_button :presence, true, :value => true, name: "presence_#{s.id}" %>