#39* Use background color to show error fields ins

Using the default rails field_error_proc may lead to some layout headaches--your form looks perfect until, uh-oh, someone entered an invalid email address and Rails adds a fieldWithError-styled div that wraps around the problem field.

While this works in many cases, some pixel-perfect layouts may not be able to tolerate the 2-pixel padding around the text_field caused by the red border. An alternative is to change the background color of the offending field.

Include the following code in environment.rb (or use a "require" like I do):

ActionView::Base.field_error_proc = Proc.new do |html_tag, instance|
       error_style = "background-color: #ffff80"
       if html_tag =~ /<(input|textarea|select)[^>]+style=/
         style_attribute = html_tag =~ /style=['"]/
         html_tag.insert(style_attribute + 7, "#{error_style}; ")
       elsif html_tag =~ /<(input|textarea|select)/
         first_whitespace = html_tag =~ /\s/
         html_tag[first_whitespace] = " style='#{error_style}' "
      end
      html_tag
    end