ConcatOperator

class ConcatOperator  {
  
  var disposeBag : DisposeBag = DisposeBag()
  
  func getEmployeeData(){
    getEmployeeFromCacheAndFallBackToOnline()
    .subscribe(onNext: { (goodReceiptPOList) in
      print(goodReceiptPOList.count)
    }, onError: {
      (error) in
      
    }, onCompleted: {
      
    }).disposed(by: disposeBag)
  }
  
  func getEmployeeFromCache() -> Observable<[Employee]> {
    return Observable.create({ (observer) -> Disposable in
      let employeeArray = // Getting Data from Local
      observer.onNext(employeeArray)
      observer.onCompleted()
      return Disposables.create()
    })
  }
  
  func getEmployeeFromOnline() -> Observable<[Employee]> {
    return Observable.create({ (observer) -> Disposable in
      let employeeArray = // Getting Data from Online
      observer.onNext(employeeArray)
      observer.onCompleted()
      return Disposables.create()
    })
  }
  
  func getEmployeeFromCacheAndFallBackToOnline() -> Observable<[Employee]> {
    return Observable.concat(getEmployeeFromCache(),
            getEmployeeFromOnline()).single({ (employeeList) -> Bool in
                              return employeeList.count > 0
                             }).take(1)
  }
  
  
}