Idiomatic way to handle nested nullable objects in scala?

Question

I'm working with scala and recently inherited some Java code which needs to be grafted in and unfortunately rewriting it in Scala isn't in the cards. It has a deeply nested object structure, and any level can be null. Often I only care about the values deep within the nesting.

Ideally, I'd do something like this:

 Option(foo.blah.blarg.doh)

But if any of foo.blah.blarg is null, this will generate a NPE.

For now I've taken to wrapping it in a Try:

Try(Option(foo.blah.blarg.doh)).getOrElse(None)

Note that using .toOption doesn't work quite right as it can lead to a Some(null) if the final bit of the chain is null.

I'm not particularly fond of this construct, any other ideas out there?

Answer 1

flatMap it:

for {
  a <- Option(foo)
  b <- Option(a.blah)
  c <- Option(b.blarg)
  d <- Option(c.doh)
} yield d