ActionController::Flash

A simple helper method for showing the flash message. Includes optional fade in seconds (view needs javascript_include_tag defaults if you desire fade effect):

def show_flash_message(options={})
html = content_tag(:div, flash.collect{ |key,msg| content_tag(:div, msg, :class => key) }, :id => 'flash-message')
if options.key?(:fade)
  html << content_tag(:script, "setTimeout(\\"new Effect.Fade('flash-message');\\",#{options[:fade]*1000})", :type => 'text/javascript')
end
html
end

simply call in your views then using:

<%= show_flash_message(:fade => 4) %>

If your controllers are redirecting more than once, the flash contents will be lost. To avoid it, execute flash.keep before each redirection.

Check ActionController::Flash::FlashHash for more handy methods (discard, now, ...)

Building on the below excellent example, you can create something with default options for how long it's displayed and how long the fade is, and highlight:

def show_flash(options={})
options = {:fade => 3, :display => 3, :highlight => true}.merge(options)
html = content_tag(:div, flash.collect{ |key,msg| content_tag(:div, msg, :class => key, :attributes => "style = display: none;") }, :id => 'flash-message')
html << content_tag(:script, "new Effect.Highlight('flash-message');") if options[:highlight]
html << content_tag(:script, "$('flash-message').appear();")
html << content_tag(:script, "setTimeout(\\"$('flash-message').fade({duration: #{options[:fade]}});\\", #{options[:display]*1000});")
end

This is helper method which can be easily used to handle flash for ajax calls ##call it in your js.erb def flash_display response = "" flash.each do |name, msg| msg=msg+"".html_safe response = response + content_tag(:div, msg, :id => "flash_# {name}",:class=>"alert alert-danger") do "#{msg}".html_safe
end end flash.discard response end

so in your controller,

def get_data_and_update_div

@user_details=User.get_details if @user_details.nil? flash.now[:error]="Add your details and then submit" format.js { render 'shared/error_messages'} end

in error_messages.js.erb

$('#flash_messages').html("<%= escape_javascript raw(flash_display) %>");

in view file

<div id="flash_messages">
<% if flash[:error] %>
 <%= content_tag :div, flash['value'], :id =>"flash_error" %>

<% end %>