checkboxs in a table created via form_for

Question

I'm new to RoR so apologies if the answer is super simple. I'm trying to create a table that allows users to select other users that can collaborate on a wiki. The issue I'm having is that no matter which checkbox you select on the table. It only toggles the topmost option.

here is the code in question:

<%= form_for [@wiki, @wiki.collaborators.build] do |f| %>
  <table class="bordered hoverable">
    <tbody>
      <% @users.each do |user| %>
        <tr>
          <td><%= user.name %></td>
          <td class="right-align"><%= f.check_box :user_id %><%= f.label :user_id, "Give Access" %></td>
        </tr>
      <% end %>  
    </tbody>
  </table><br /><br />

the controller values in new

def new
  @wiki = Wiki.find(params[:wiki_id])
  @collaborator = Collaborator.new
  @users = (User.all - [current_user])
end

Answer 1

The problem here is that through check_box 's you can't get more than one user selected. In order to select multiple data, you need to use f.collection_select .

Here's how:

<%= f.collection_select :user_id, @users, :id, :name, {prompt: "Please select collaborators"}, {multiple: true} %>

Answer 2

To select multiple the the name of the checkbox should not be :user but contain the user id. Try something like that:

<%= form_for [@wiki, @wiki.collaborators.build] do |f| %>
  <%= f.fields_for :collaborators do |c| %>
    <table class="bordered hoverable">
      <tbody>
        <% @users.each do |user| %>
          <tr>
            <td><%= user.name %></td>
            <td class="right-align"><%= c.check_box user.id %><%= f.label user.id, "Give Access" %></td>
          </tr>
        <% end %>  
      </tbody>
    </table><br /><br />
  <% end %>  
<% end %>  

The controller would then recieve params like that:

{:collaborators => {1 => '0', 2 => '1'}

showing that user with id 1 was not checked, user with id 2 was checked