Uploading a file using Net::SFTP

Question

I have a method to upload a file using the Net::SFTP gem:

class Uploader
 def initialize(host,user,password)
 @host = host
 @user = user
 @password = password
 end
 def upload(local_file_path,remote_file_path)
 Net::SFTP.start(@host,@user,:password => @password) do |sftp|
 sftp.upload!(local_file_path,remote_file_path) do |event,uploader,*args|
 case event
 when :open
 Rails.logger("Starting upload...")
 when :finished
 Rails.logger("Finishing upload...")
 end
 end
 end
 end
end

The upload method seems rather large to me. Any suggestions on how I could split it up into smaller components?

Answer 1

I don't see much reason to worry about this method's length. At least not right now - if you add more event handling, yeah, it might become a little cumbersome. But for what it does now, there's no pressing need to do anything.

I would recommend more whitespace, though. There's no reason to compress,every,line,that,has,commas,in,it. Just makes it harder to read.

I'm also fairly sure that the :finished event is actually called :finish

Structurally, just for the sake of it, you could do something like:

class Uploader
 attr_reader :host, :user, :password
 def initialize(host, user, password)
 @host = host
 @user = user
 @password = password
 end
 def upload(local_file_path, remote_file_path)
 Net::SFTP.start(host, user, password: password) do |sftp|
 sftp.upload!(local_file_path, remote_file_path) do |event, uploader, *args|
 send(event, uploader, *args) if respond_to?(event, true)
 end
 end
 end
 private
 def open(uploader, *args)
 Rails.logger("Starting upload...")
 end
 def close(uploader, *args)
 Rails.logger("Upload complete")
 end
 def finish(uploader, *args)
 Rails.logger("All done")
 end
end

Basically, we're handling events with methods instead of a case block. I've added the close method/event handler as an example.

Answer 2

The docs suggest creating a custom handler:

... you can create custom handler objects that respond to certain methods, and then pass your handler to the uploader:

class CustomHandler
 def on_open(uploader, file)
 puts "starting upload: #{file.local} -> #{file.remote} (#{file.size} bytes)"
 end
 def on_put(uploader, file, offset, data)
 puts "writing #{data.length} bytes to #{file.remote} starting at #{offset}"
 end
 def on_close(uploader, file)
 puts "finished with #{file.remote}"
 end
 def on_mkdir(uploader, path)
 puts "creating directory #{path}"
 end
 def on_finish(uploader)
 puts "all done!"
 end
end
sftp.upload!("local", "remote", :progress => CustomHandler.new)