RxJava - Iterating a Single<Collection>

Question

I have a method which returns a Single<Collection<SomeObj>>. What is the correct way to iterate through it so I can apply a filter and only return the SomeObj I'm looking for?

Answer 1

You could use flattenAsObservable. It converts a single of an iterable to an observable that emits each item:

getItems()
    .flattenAsObservable { it }
    .filter { <some condition> }
    .first()

Here the getItems returns Single<Collection<SomeObj>>.

This code will return an observable. You might need to convert it back to a single. Be careful, if there are no elements, then it cannot be covered to single unless you specify a default value.