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Discussion on: Smart Event Listeners

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Dwayne Crooks • • Edited

Update: I've found the following function to be useful when implementing smart event listeners.

fromMaybe : Maybe a -> JD.Decoder a
fromMaybe ma =
    case ma of
        Just a ->
            JD.succeed a

        Nothing ->
            JD.fail "ignored"
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Then, onVolumeInput becomes

onVolumeInput : (Volume -> msg) -> H.Attribute msg
onVolumeInput onVolume =
    HE.targetValue
        |> JD.andThen (Volume.fromString >> Maybe.map onVolume >> JD.fromMaybe)
        |> HE.on "input"
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See this commit for a full example.