Deploy with capistrano through sftp (no ssh available)

I was wondering if it is possible to deploy a rail application to an host for which I only have sftp access. (No ssh access, unfortunately).

I found this page开发者_JAVA技巧,

http://codesnippets.joyent.com/posts/show/1271

which it makes me think it could be done, although it really is not clear with me what I should do with such file, nor whether this also enables also cap deploy:setup through sftp... Any suggestions please? Thanks!