Custom AWS Params

Sample to add and read extra attribute from AWS for each file:

def my_hook_for_on_uploader(args)
  args[:aws_settings][:aws_file_upload_settings] = lambda{|settings|
   settings[:cache_control] = 'max-age=36001, public'
   settings
 }
 args[:aws_settings][:aws_file_read_settings] = lambda{|data, s3_file|  unless s3_file.is_a?(String)
    data[:cache_control] = (s3_file.is_a?(Aws::S3::ObjectSummary) ? s3_file.object : s3_file).cache_control
  end
 data
 }
end

The result of reading file is like:

{
    "name" : "one.jpg", 
    "key" : "/one.jpg", 
    "url" : "https://abcd.cloudfront.net/one.jpg", 
    "is_folder" : false, 
    "size" : 100476.0, 
    "format" : "image", 
    "deleteUrl" : "", 
    "thumb" : "https://abcd.cloudfront.net/thumb/one-jpg.jpg", 
    "type" : "", 
    "created_at" : "2016-10-26T10:37:59.000-04:00", 
    "dimension" : "", 
    "cache_control" : "max-age=36001, public"
}

More AWS attributes here:
https://docs.aws.amazon.com/sdkforruby/api/Aws/S3/Object.html#upload_file-instance_method