func getAllDevices(userID: String, completionHandler:@escaping (([DeviceRoom])->Void)){

    var homeID: String = ""

    _ = Firestore.firestore().collection("users/4oKS4F0uejdyxEZZ340v/homes" ).limit(to: 1).getDocuments{ (homeSnap,error) in
      if error != nil {
        print(error?.localizedDescription as Any)
        return
      }else {
        for home in (homeSnap?.documents)! {
          homeID = home.documentID
          _ = Firestore.firestore().collection("users/4oKS4F0uejdyxEZZ340v/homes/\(homeID)/rooms").getDocuments(completion: { (roomsSnap, error) in
            if error != nil{
              print(error?.localizedDescription)
              return
            }else{
              for room in (roomsSnap?.documents)! {
                _ = Firestore.firestore().collection("users/4oKS4F0uejdyxEZZ340v/homes/\(homeID)/rooms/\(room.documentID)/devices").getDocuments(completion: { (devicesSnap, error) in
                  if error != nil{
                    print(error.debugDescription)
                    return
                  }else{
                    for device in (devicesSnap?.documents)! {
                      do{
                        let device = try DeviceRoom(fromDictionary: device.data())
                        self.devices.append(device)
                        print(self.devices)
                      }catch {
                        print("errore")
                      }
                    }
                  }
                })
              }
            }
            completionHandler(self.devices)
          })
        }
      }
    }
  }