As a field repair like you stated and you really want to continue to fly your fix is about as good as you could do. Like everybody says though, replace the spar ASAP. Damage to the spar may extend further then you can see or there may be damage in another area, in either case the spar has been weakened and the likelyhood of another failure increased.
Another possible "field repair": if it's a clean break, not a long split is an internal ferrule glued in, that wouldn't have worked in your case unless you could've knocked the ferrule out of the other spreader and glued it into the split side. Again though replace the spar ASAP.
We could help you list out a proper field repair kit with spare rods and all but as you get more kites you'll just leave it at home and fly something else anyway