Validate Attachment Content Type Paperclip

Question

Is it possible to enforce a \'content type\' validation in paperclip without enforcing a \'presence\' validation (i.e. allow blanks)? I currently have:

class         


        

Answer 1

Working example

In the following model only image/png, image/gif and image/jpeg are valid content types for the image attachment.

class Photo
  has_attached_file :image
  validates_attachment_content_type :image, 
                                    :content_type => /^image\/(png|gif|jpeg)/
end

Specs

describe Photo do
  it { should validate_attachment_content_type(:image).  
              allowing('image/png', 'image/gif', 'image/jpeg').      
              rejecting('text/plain', 'text/xml', 'image/abc', 'some_image/png') }
end

More info

You could also take a look at the AttachmentContentTypeValidator class with is responsible for doing the validation.

Or take a look at its tests which contain more examples.