Araldite Super Strength Epoxy Adhesive will be the best glue to use for this repair. Ensure the surfaces are clean and dry and if possible lightly rough the surfaces to provide a good 'key' for the adhesive. For best result clamp the repair firmly and allow at least 24 hours for full cure. If possible try not to put excessive stress on the repair for a couple of days. If possible installing a couple of screws through the handle into the outside of the door would be advisable as glue only is not really the ideal fix.