Tutorial on UIDocument and iCloud

Will the tutorial https://www.raywenderlich.com/12779/icloud-and-uidocument-beyond-the-basics-part-1 work with the current iOS, Xcode, and Swift versions?

Strictly speaking no, that tutorial is written in Objective C. But it does build and run with Xcode 8.2!

For a modern example to follow you might want to look at ShapeEdit, a sample project from Apple.