app/views/tasks/completed_tasks.html.erb
<% title "Completed Tasks" %>
<div id="left_stuff">
<fieldset class="index" id="date_selector">
<%= form_tag({controller: 'tasks', action: 'completed_tasks'}, method: :get) do %>
<%= label_tag :start_date %><br />
<%= date_select(:dates, :start, default: @start) %>
<br />
<%= label_tag :end_date %><br />
<%= date_select(:dates, :end, default: @end) %>
<br />
<%= submit_tag 'Update dates' %>
<% end %>
</fieldset>
</div>
<h2>Recent completions of: <%= @task.name %></h2>
<%= render partial: "task_items" %>
<br />
<%= link_to "Back to List", tasks_path %>