collection check box

checkbox

<div class="staff-page form-staff-new-page">
  <%= render 'layouts/staff_top_bar' %>

  <div class="content">
    <a href="<%= staff_forms_path %>" class="back-button">&lt; Back</a>
    <div class="top-group">
      <div class="page-title my-7">New Session</div>
    </div>


    <% if @staff.role == "staff" %>
      <div class="form">
      <%= form_with url: staff_forms_path, method: :post  do |f| %>
        <div>
          <%= f.label :clazz, 'Select a class' %>
          <%= f.select :clazz, @staff.clazzes.map {|c| [c.name, c.id]}, required: true %>
        </div>
        <%= f.submit 'Start new session' %>
      <% end %>
    </div>
    <% else %>
    <div class="form mx-auto">
      <%= form_with url: staff_forms_path, method: :post  do |f| %>
        <div>
          <div class='flex items-center mb-10'>
           <div class="text-md mr-4">
            <div>Select Classes:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</div>
          </div>
            <div class="mr-6 text-xs">
              <%= f.collection_check_boxes(:clazz, @staff.clazzes.map { |c| 
                  [ ' ' + c.name + ' ', c.id]
              }, :last, :first) %>
            </div>
          </div>
          <% flash.each do |type, msg| %>
            <div class='text-xs text-red-400 -mt-5'>
              <%= msg %>
            </div>
          <% end %>
          <div class="flex mt-5">
            <div class="text-md">Session Type:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</div>
            <div class="text-xs"><%= f.select :form_type, ['FTGP', 'CCE lesson', 'School-based Activity', 'Others']%></div>
          </div>
          <div class="flex my-10 items-center">
            <div class="text-md whitespace-nowrap">Session Title:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</div>
            <div class="text-md">
                <%= f.text_field  :session_title, placeholder: "Session Title", :maxlength=>"160", :size=>"30", :height=>"0", :required=>true %> 
            </div>
          </div>

            <div class="flex">
            <div class="text-md mr-3">End Date:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</div> 
            <div class="text-sm mb-12">
              <%= f.date_field :expire_date, value: Date.tomorrow + 7 %>
            </div>
          </div>
        </div>
        <%= f.submit 'Start new session' %>
      <% end %>
    </div>
    <% end %>
  </div>
</div>