Curing onions

The onions that I grew from heat treated sets are now flopping over and beginning to look as though they are ready to harvest. Books seem to differ as to what is next. Some say, lift the roots just a bit to expose the underneath of the onion and leave like this for the roots to dry then pull the onions up and dry on a rack. Others say, lift completely and then dry on a rack.
What have been others experiences please?

Thanks DD.
One other thing please. I dry them on greenhouse staging which is under a veranda so that the sun doesn't burn them but the air can circulate. Should they be out in full sun? I can move the staging easily enough from the shade of the veranda to the full sun in the garden.

You could just leave them laying where they've been grown, it's certainly dry and sunny enough atm