I would like to use a single file-field for multiple formats. It was my understanding that Paperclip was smart enough to only scale images and leave other formats alone, but this doesn't seem to work for flv's (which returns imagemagick/identify-errors). Is there any way to help Paperclip a bit and explicitly setup specific formats to scale?
UPDATE: Apparently, these errors are prevented with :whiny=>false (thanks fl00r), which works fine for regular uploads. However, what I'm trying to do here is uploading the file by FTP, and later on create a new record by code with a File.new([:path]) in the attachment-parameter. This works like a charm for images, but the :whiny=>false-trick won't do it anymore. Does anyone has any tips on this?
set :whiny option to false:
has_attached_file :my_attach, :whiny => false ...
it won't help peparclip to process images only, but it won't throw errors if processing failed
UPD
Processing for images only:
has_attached_file :file,
:styles => lambda{ |a| ["image/jpeg", "image/png"].include?( a.content_type ) ? { :small => "90x90#" } : {} }
where you can add as more as you like content types into ["image/jpeg", "image/png"] array
You can also use paperclip's callback for post-processing of images, and instruct paperclip to only process images. If the before_post_process callback returns false, the processing stops.
before_post_process :process_only_images
def process_only_images
%w(image/jpeg, image/png,image/gif,image/pjpeg, image/x-png).include?(attachment_content_type)
end
Check paperclip's documentation for more details at https://github.com/thoughtbot/paperclip#events
来源：https://stackoverflow.com/questions/5289674/paperclip-process-images-only