> Note: Dash.NET is currently considered experimental. If your organization is interested in sponsoring Dash.NET, please get in touch.

# Live Updating Components

## The `DCC.Interval.interval` Component

Components in Dash usually update through user interaction like selecting a dropdown, dragging a slider, or hovering over points.

If you're building an application for monitoring, you may want to update components in your application every few seconds or minutes.

The `DCC.Interval.interval` element allows you to update components on a predefined interval. The `n_intervals` property is an integer that is automatically incremented every time `interval` milliseconds pass. You can listen to this variable inside your app's `callback` to fire the callback on a predefined interval.

This example pulls data from live satellite feeds and updates the graph and the text every second.

    open Dash.NET
    open System

    let dslLayout =
        Html.div [
            Attr.children [
                Html.h1 [ Attr.id "time_display"; Attr.children "The time is:" ]
                Interval.interval "interval_component" [
                    Interval.Attr.interval 1000
                    Interval.Attr.nIntervals 0
                ]
            ]
        ]

    let changeTextCallback =
        Callback.singleOut (
            "interval_component" @. (CustomProperty "n_intervals"),
            "time_display" @. Children,
            fun (nIntervals: int) ->
                "time_display" @. Children => sprintf "The time is: %s" (DateTimeOffset.Now.ToString())
            , PreventInitialCall = false
        )

    [<EntryPoint>]
    let main args =
        DashApp.initDefault()
        |> DashApp.withLayout dslLayout
        |> DashApp.addCallback changeTextCallback
        |> DashApp.run args

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