Rails4: How to permit a hash with dynamic keys in params?
Rails 5.1+ params.require(:post).permit(:files => {}) Rails 5 params.require(:post).tap do |whitelisted| whitelisted[:files] = params[:post][:files].permit! end Rails 4 and below params.require(:post).tap do |whitelisted| whitelisted[:files] = params[:post][:files] end