I am currently reading Harry Potter and the Deathly Hallows?

The way it happens in the movie is the same way it happens in the book.....Harry and co. are at Grimmauld place, Hermione has already mentioned that Snitches have flesh memories and that she was nervous that something would happen when the Prime Minister put it in Harry's hand. Harry also must know this since he should pretty much know everything to do with quidditch especially snitches. So while they are chillin in Grimmauld Place he is messing with the snitch and remembers that he didn't catch it with is hand, but almost swallowed it. That's when he puts his lips on it and the words written by Dumbledore are revealed to him. He never opens the snitch until the end.