When the compiler starts giving weird error messages, delete the temporary .aso files, which are some kind of class cache.

C:\Documents and Settings\[user]\Local Settings\Application Data\Macromedia\Flash MX 2004\en\Configuration\Classes\aso

Takes a string, such as a post title ("Rat Brains Fly Planes") and convets it into a ruby style variable name that can be used as an id or permalink url ("rat_brains_fly_planes")

Posted by Duane Johnson on rails list:
Here's the modified String class. This one
squeezes non-alphanumeric character sequences down to one underscore
and also makes sure it doesn't start or end with an underscore:

class String
  def rubify
    downcase.gsub(/\W/, ' ').squeeze.strip.gsub(' ', '_')
  end

  def rubify!
    replace rubify
  end
end

"!Hell93 o3#$@ the___re , dude".rubify
=> "hel93_o3_the_re_dude"

Luke Redpath suggested the following naming convention:
ID is short for identification the related verb of which is identify.

The appropriate verify_ macro would be verify_identity_of

A more conventional Ruby idiom would be to_id() (like to_s, to_i etc.).

"My, what a beautiful day!".to_id

=> "my_what_a_beautiful_day"

If thats not clear enough or possibly confusing with the normal use of id in a Rails app, perhaps to_identifier() instead.

posted by Scott Raymond on rails list

I generally like to add something like this to my application_helper.rb:

def flash_div *keys
  keys.collect { |key| content_tag(:div, flash[key],
                                   :class => "flash #{key}") if flash[key] }.join
end

...and then this in my layouts/application.rhtml:

<%= flash_div :warning, :notice %>

Now, if my controller puts anything into flash[:warning] or flash[:notice],
they'll render like:

<div class="flash warning">Warning here</div>
<div class="flash notice">Notice here</div>

Nice and DRY, and easy to style. If I ever need some other flash key besides :warning or :notice, I can just add an argument to the flash_div call and I'm set.

a proposal from Luke Randall on the rails mailing list

:notice for positive feedback (action successful, etc)
:message for neutral feedback (reminders, etc)
:warning for negative feedback (action unsuccessful, error encountered, etc)

Then, in your controller or view you could place code such as the following:

FLASH_NAMES = [:notice, :warning, :message]

<% for name in FLASH_NAMES %>
  <% if flash[name] %>
    <%= "<div id=\"#{name}\">#{flash[name]}</div>" %>
  <% end %>
<% end %>