elm-messages-to-logging-data.elm

type Msg
    = PlayVideo VideoId
    | VideoPlayAdvanced { currentSecond : Int, totalLength : Int }
    | ReadTextAloud
    | Login AuthToken UserInformation


logMessage : Msg -> Maybe { message : String, data : Json.Encode.Value }
logMessage msg =
    case msg of
        PlayVideo (VideoId id) ->
            Just { message = "PlayVideo", data = Json.Encode.int id }

        VideoPlayAdvanced ->
            Nothing

        Login AuthToken UserInformation ->
            Just { message = "Login", data = Json.Encode.null }

        ReadTextAloud ->
            Just { message = "ReadTextAloud", data = Json.Encode.null }

        -- if you're not optimized, you _could_ replace the previous line entry and any others with this...but see below
        _ ->
            Just { message = Debug.toString msg, data = Json.Encode.null }