HTTP request without request in Elm 0.18

Question

I want to do something very un-functional and make an HTTP request in elm without processing any kind of response. Basically something like this:

testView : Html Msg
testView =
  div [] [
    button [onClick TestAction] [text "Test Action"]
  ]

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
      ...
        TestAction ->
          ( model, testActionCmd )
      ...

import Http
import HttpBuilder exposing (..)
...
testActionCmd : Cmd Msg
testActionCmd =
  ( "http://localhost:4000/fakeurl" )
    |> get  -- this is a side effect; unrelated to the Msg below
  Cmd.none  -- this is what I want to return

Is there a way to do something like this in Elm?

Emmanuel Rosa Emmanuel Rosa · Accepted Answer · 2017-09-28T22:02:01

In short, no, you won't be able to do that (not without writing your own effect manager or using ports).

The "problem" is that the Http module allows you to create a Task which you then need to convert into a Cmd to perform the task. But to go from a Task to a Cmd you need to provide a Msg. See http://package.elm-lang.org/packages/elm-lang/core/5.1.1/Task

So what you'll need to do is create one of those Noop messages.

HTTP request without request in Elm 0.18

1 Answers