RxSwift - block/stop/ignore event if condition met-CodePudding

After filtering an Observable list, I might have an empty list. I'm only interested in events that contain a populated list. Is there any way to stop empty events propagating to onNext?


        let source: BehaviorRelay<[Int]> = .init(value: [])

        source
            .map { nums -> [Int] in
                return nums.filter { $0 < 10 }
            }
            /// What can go here to stop/block/ignore an empty list
            .subscribe(onNext: { nums in
               print("OKPDX \(nums)")
            })

        source.accept([1, 9, 13])
        // prints "[1, 9]" (all good)

        source.accept([20, 22, 101])
        // prints "[]" (not desirable, I'd rather not know)

CodePudding user response：

What about using .filter? You could do this:

.map { nums -> [Int] in
        return nums.filter { $0 < 10 }
     }
.filter { !$0.isEmpty }

Or you could also validate that whenever you get an event like this:

.subscribe(onNext: { nums in
      guard !nums.isEmpty else { return }
      print("OKPDX \(nums)")
})