Rails: An elegant way to display a message when there are no elements in database

Question

I realized that I\'m writing a lot of code similar to this one:

<% unless @messages.blank? %>
  <% @messages.each do |message|  %>
    <%# cod         


        

Answer 1

As a note, you may as well just iterate over an empty array if you're looking for efficiency of expression:

<% @messages.each do |message|  %>
  <%# code or partial to dispaly the message %>
<% end %>
<% if (@messages.blank?) %>
  You have no messages.
<% end %>

While this does not handle @messages being nil, it should work for most situations. Introducing irregular extensions to what should be a routine view is probably complicating an otherwise simple thing.

What might be a better approach is to define a partial and a helper to render "empty" sections if these are reasonably complex:

<% render_each(:message) do |message|  %>
  <%# code or partial to dispaly the message %>
<% end %>

# common/empty/_messages.erb
You have no messages.

Where you might define this as:

def render_each(item, &block)
  plural = "#{item.to_s.pluralize}"
  items = instance_variable_get("@#{plural}")
  if (items.blank?)
    render(:partial => "common/empty/#{plural}")
  else
    items.each(&block)
  end
end