Sorting in Rails views without displaying duplicates

How do I sort in Rails view but without displaying any duplicate values?

I have the following ERB code.

  <% @todos.each do |todo| %>
    <h1><%= todo.due %></h1>
    <br />
    <%= todo.description %><b><%= todo.list %></b>
    <br />
  <% end %>

And will output the following:

2011-03-09 10:39:00 -0600

My Todo For Today My List

2011-03-09 10:39:00 GMT

My Another Todo for Toda开发者_StackOverflow社区y My List 2

2011-03-09 10:39:00 GMT

And Another Todo for Today My List

However, how do I make it output with the following format in Rails?

2011-03-09 10:39:00 GMT

My Todo For Today My List

And Another Todo for Today My List

My Another Todo for Today My List 2

@todos is an Array and @todos.uniq! removes duplicates. There is a method sort! in the Array class which should do what you are looking for.

You should use group_by method

<% @todos.group_by(&:due).each do |due, todos| %>
  <h1><%= due %></h1>
  <% todos.each do |todo| %>
    <p><%= todo.description %> <b><%= todo.list %></b></p>
  <% end %>
<% end %>

I would add a method to todo model, that returns list of items by a due date:

#models/todo.rb    
def self.get_todo_by_due(due_date)
   return Todo.where(:due => due_date)
end

And then change view:

<%distinct_due_dates = Todo.select("DISTINCT(due)") %>

<%distinct_due_dates.each do |item|%>
  <% due_date = item.due %>
  <h1><%= due_date %></h1>
  <% get_todo_by_due(due_date).each do |todo|%>
    <br />
    <%= todo.description %><b><%= todo.list %></b>
    <br />
  <% end%>
<% end%>