How to turn a Msg into a Cmd Msg?

Only Use Sparsely: Better split the update function into multiple smaller functions.
Problem
Solution
Alternative Solution
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type Msg =
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  LoginSucceeded User
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  | InfoMessage String
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update : Msg -> Model -> (Model, Cmd Msg)
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update msg model =
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  case msg of
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    LoginSucceeded newUser ->
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      ( { model | currentUser = newUser }
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      , Cmd.none
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      )
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    InfoMessage message ->
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      ( { model | message = Just message }
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      , Cmd.none
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      )
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1
type Msg =
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  LoginSucceeded User
3
  | InfoMessage String
4
  
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update : Msg -> Model -> (Model, Cmd Msg)
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update msg model =
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  case msg of
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    LoginSucceeded newUser ->
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      ( { model | currentUser = newUser }
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      , sendMsg <| InfoMessage "Login Successful"
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      )
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    InfoMessage message ->
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      ( { model | message = Just message }
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      , Cmd.none
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      )
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​
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sendMsg : msg -> Cmd msg
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sendMsg msg =
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  Task.succeed msg
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  |> Task.perform identity
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1
type Msg =
2
  LoginSucceeded User
3
  | InfoMessage String
4
  
5
update : Msg -> Model -> (Model, Cmd Msg)
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update msg model =
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  case msg of
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    LoginSucceeded newUser ->
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      ( model
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        |> updateUser newUser
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        |> updateMessage "Login Successful"
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      , Cmd.none
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      )
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    InfoMessage message ->
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      ( model |> updateMessage message
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      , Cmd.none
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      )
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​
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updateUser : User -> Model -> Model
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updateUser user model =
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  { model | currentUser = user }
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​
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updateMessage : String -> Model -> Model
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updateMessage message model =
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  { model | message = Just message }
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This is the a better solution
Question
How can I display a Message after a user logged in?
Answer
Use the following function:
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sendMsg : msg -> Cmd msg
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sendMsg msg =
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  Task.succeed msg
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  |> Task.perform identity
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Further reading
📄Article: How to turn a Msg into a Cmd Msg in Elm? by Wouter In t Velt

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