Exemplo de uso de flash message em app Rails

flash_example.txt

# application.html.erb

<%= render_flash_messages %>

# application_helper.rb

def has_flash_messages?
  flashes = [:alert, :notice, :warning, :message, :failure]
  flash and flashes.find { |key| flash.has_key?(key) }
end

def render_flash_messages
  return unless has_flash_messages?
  buffer = "<div id=\"flash\">"
  #[:alert, :notice, :warning, :message, :failure].each do |name|
  flash.each do |name, text|
    html_class = (:notice == name or :message == name) ? "flash_notice" : "flash_alert"
    buffer << "<div id=\"messages\"><dl class=\"#{html_class}\"><dt>#{flash[name]}</dt></dl></div>"
  end
  buffer << "</div>"
  buffer.html_safe
end

# application.css

#flash {
	margin: 1em 0;
}

.flash_notice,
.flash_alert  {
	background-repeat: no-repeat;
	background-position: 2em 50%;
	margin: 1em 0;
	padding: 1em 0 1em 5em;
	border: solid 1px #338000
}

.flash_alert  {
	color: red;
	background-color: #ffc;
	background-image: url(/images/flash_alert.gif);
	border: solid 1px #f00
}


.flash_notice  {
	color: red;
	background-color: #e6ffd5;
	background-image: url(/images/flash_notice.png);
	border: solid 1px #338000
}


.flash_notice dt,
.flash_alert dt {
	color: black;
	font-weight: bold;
	margin: 0;
	padding: 0;
	width: 95%
}

.flash_notice dd,
.flash_alert dd {
	width: 95%
}