Preferred way to deliver a document

Targets iOS
1

An iOS application that creates a document (txt file, pdf, html whatever).
What is the prefered method to deliver that document in a manner that it can be printed?

Email it to the user?

Airprint could be an option, but no way to know if the user has a compatible printer (I know for example that I don’t)

2

Email is the most used.

3

Use UIActivity and let the user choose how they want to take it. That way they can save it to dropbox to print later, print directly, email it to themselves, etc.