An interpolated symbol is converted to an string.
An interpolated symbol is converted to an string.

    # irb
    >> field = :attachment
    => :attachment
    >> "#{field}_file_name"
    => "attachment_file_name"

thirdthing/typus,typus/typus,baban/typus,wollzelle/typus,baban/typus,chiragshah/typus,brainsome-de/typus,baban/typus,typus/typus,thirdthing/typus,oruen/typus,chiragshah/typus,burn-notice/typus,gkleiman/typus_3dglabs,wollzelle/typus,chiragshah/typus,burn-notice/typus,brainsome-de/typus,readyfor/typus,wollzelle/typus,wollzelle/typus,thirdthing/typus,gkleiman/typus_3dglabs,oruen/typus,typus/typus,chiragshah/typus,readyfor/typus,readyfor/typus,burn-notice/typus,thirdthing/typus,readyfor/typus,baban/typus,typus/typus,burn-notice/typus,brainsome-de/typus,brainsome-de/typus