Elm Batched Logging Example

elm-event-logging-batch.elm

type Msg
    = SendBatchLogEvents
    | BatchEventLogSuccessful Int


type alias EventData =
    { message : String
    , data : Json.Encode.Value
    }


type alias Model =
    { events : List EventData
    }


subscriptions : Model -> Sub Msg
subscriptions model =
    Sub.batch
        [ Time.every (30 * Time.second) SendBatchLogEvents
        ]


update : Msg -> Model -> Cmd Msg
update msg model =
    -- Note: if a batch call took more than 30 seconds, events could be sent more than once --
    -- you'd want to account for that.
    case msg of
        SendBatchLogEvents ->
            -- this would generate BatchEventLogSuccessful message with the number of events logged
            ( model, LoggingApi.logBatch model.events )

        BatchEventLogSuccessful numberOfEventsLogged ->
            -- now that they're it's successfully logged, drop the events
            ( { model | events = List.drop numberOfEventsLogged model.events }, Cmd.none )