Simple fading flash[:notice] in Rails with jQuery

fading_flash_notice_rails

# I struggled with getting a fading flash[:notice] that would work both with standard served pages as well
# as ajax requests. I saw a number of posts online but did not have luck with or they seemed too 
# complicated. This is what I ended up with from experimentation.

# Place the following code in application_helper.rb. Note that you need to either change or name your
# containers as I have in this code:

# application_helper.rb
module ApplicationHelper
  
  def fading_flash_notice
    # note: you must have a div with id='notices' or rename the div appended to below with your element which
    # is the container for the flash messages
    return '' if !flash[:notice]
    notice_id = rand.to_s.gsub(/\./, '')
    notice = <<-EOF
      $('#notices').append("<div id='#{notice_id}' class='flash_notice'>#{flash[:notice]}</div>");
      $("##{notice_id}").fadeOut(5000);
    EOF
    notice.html_safe
  end
  
end

# Then in the application template (application.html.erb) place this code in the head:
# application.html.erb

	<% if flash[:notice] %>
	<script language='javascript'>
		$(document).ready(function() {
			<%= fading_flash_notice %>
		});
	</script>
	<% end %>

# If you are sending ajax responses and they contain a flash[:notice], then just put this in your .js.erb file:
# any .js.erb ajax response

<%= fading_flash_notice %>

# If you want to add a spec to test your helper method use this:
# application_helper_spec.rb

describe ApplicationHelper do
  
  it "should return a good fading flash notice" do
    flash[:notice] = 'hello world'
    fading_flash_notice.should =~ /<div id='.*?' class='flash_notice'>hello world<\/div>/
    fading_flash_notice.should =~ /\$\(".*"\).fadeOut\(.*\);/
  end
  
end

notice_id = rand.to_s.gsub(/\./, '')
such slippery ^_^'