Something interesting I discovered today while working on an email is the ljust & rjust methods (think left & right justified) for Ruby strings. What it does is it makes sure that your string has at least a certain number of characters and if it doesn’t it adds some characters. Here’s a small code snippet from the rdocs that is pretty self explaining:

"hello".ljust(4)            #=> "hello"
"hello".ljust(20)           #=> "hello               "
"hello".ljust(20, '1234')   #=> "hello123412341234123"

"hello".rjust(4)            #=> "hello"
"hello".rjust(20)           #=> "               hello"
"hello".rjust(20, '1234')   #=> "123412341234123hello"

This is useful when sending emails with Rails that are plain text emails. It can help you align things that look like columns, like this:

INVOICE
----------------------------------------------------------

Bill to:
<%= @account.user.name %>

Description                                          Price
----------------------------------------------------------
<%= (@product.name).ljust(36) %> <%= number_to_currency(@product.amount).rjust(21) %>

If you have any questions about this invoice, please contact
<%= AppConfig['from_email'] %>.

Thank you for your business!

This would produce an email that might look like this:

INVOICE
----------------------------------------------------------

Bill to:
Michael Jordan

Description                                          Price
----------------------------------------------------------
Nike Air shoes                                        $150

If you have any questions about this invoice, please contact
support@nike.com

Thank you for your business!