Best practice method of displaying flash messages

Question

I'm wondering what's the best practice for displaying flash messages. The two main ways I've seen are using something like this scaffold generated code

<p id="notice"><%= notice %></p>

or placing code like this in your application header.

<% if !flash.empty? %>
    <div id="flash"> 
        <% flash.keys.each do |k| %> 
            <div class="<%= k %>">
                <%= flash[k] %>
            </div>  
        <% end %>   
    </div>
<% end %>

It appears to me that the first method adds more flexibility while the latter improves code readability and eliminates redundancy. Is there a method most rails developers prefer? As a side question how does scaffolding implement notice? Is it just a helper that accesses the flash hash? Why go through the trouble of using the helper when you can directly use the flash hash? Thanks

Answer 1

I'm doing it this way:

<% flash.each do |key, value| %>
  <%= content_tag :div, value, class: "flash #{key}" %>
<% end %>

Answer 2

Calling a partial keeps your application.html.erb even cleaner..

<%= render 'shared/flash_messages' if !flash.empty? %>

.. and in the partial do something like what @zolter mentioned:

<div id="flash_messages">
  <% flash.each do |key, value| %>
    <%= content_tag(:div, value, :class => "flash #{key}") %>
  <% end %>
</div>

Answer 3

Why not put the second method on a helper function so it doesn't affect code readability on layouts?

Answer 4

<% if flash[:notice] %>
  <div class="notification is-primary global-notification">
    <p class="notice"><%= notice %></p>
  </div>
<% end %>

<% if flash[:alert] %>
  <div class="notification is-danger global-notification">
    <p class="alert"><%= alert %></p>
  </div>
<% end %>