sortable column headers 使用

Controller
def list_all_tasks
　add_to_sortable_columns('listing', Task, 'task_name')
　add_to_sortable_columns('listing', Task, 'finish_time')
　add_to_sortable_columns('listing', Goal, 'name')

　@tasks = Task.find(:all, :include => :goal, :order => sortable_order('listing', Task, 'task_name'))
end

View
<%= link_to '任務名稱', sort_param('listing', Task, 'task_name') %>
<%= link_to '任務完成時間', sort_param('listing', Task, 'finish_time') %>
<%= link_to '任務所屬目標', sort_param('listing', Goal, 'name') %>

add_to_sortable_columns 是加在需要的controller's action