1. Pass the allowed content_types

has_attachment  :storage => :s3,
:content_type => ['audio/mpeg', 'audio/mp3', 'audio/MP3']

2. Place this validate method in your upload model.

def validate
errors.add_to_base("You must upload an mp3 for this song") unless self.filename

unless self.filename == nil

# Songs should only be MP3
[:content_type].each do |attr_name|
enum = attachment_options[attr_name]
unless enum.nil? || enum.include?(send(attr_name))
errors.add_to_base("The file must be an MP3")
end
end

end
end

Hope this helps!

Create a new file: initializers/custom_error_proc.rb

ActionView::Base.field_error_proc = Proc.new do |html_tag, instance|
#%(<span>*</span>) + html_tag
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

Unless you work at McDonalds (no offense), work needs to be an inspiring environment in every aspect.   After all, it’s not just a job; it’s a career and what you love (if you don’t love your job, do something different).  A passion.  Take a second and think of what’s behind the curtains of mediocrity and how it applies to you.  Is it a lack of self-motivation?  What about a lack of resources?  Inexperience?  Just not interested in what you’re doing?  I believe that if you can relate to any of these you’re steering your career down the path of mediocrity.  Don’t let it happen to you.  Fundamental problem solving (that’s a bit redundant) — discover the problem, address it, lesson learned.

Software isn’t designed in an IDE or other tool. It’s imagined and created in our heads. - Andy Hunt, from Refactor Your WetWare : Pragmatic Thinking and Learning

I’m currently reading yet another wonderful book from the boys over at Pragmatic Programmers called “Refactor Your WetWare : Pragmatic Thinking and Learning“.  So far, it’s a great read.  I wouldn’t expect anything less from author, Andy Hunt. He addresses a common issue programmers are continuously confronted with — learning more. Not just new technologies or programming languages, but learning in the general sense & the mechanics of continued education.

I highly recommend checking it out. I’m sure many of my upcoming posts will be about concepts discussed in this book.

“Refactor Your WetWare : Pragmatic Thinking and Learning” will be the catalyst of your future as a software engineer.