Asset dependency adder for ELM

1. Install parcel-transformer-elm-assets with

   npm install -D parcel-transformer-elm-assets

2. Simply add parcel-transformer-elm-assets to the transformers like so,

   {
       "transformers": {
           "*.js": ["parcel-transformer-elm-assets", "..."]
       }
   }

3. In your elm files, you can prefix any asset with ASSET_URL:[relative_path_to_asset]

   view : Model -> Html Msg
   view model =
       div []
           [ img 
               [ src "ASSET_URL:../assets/red-bolt.png" ] 
               [] 
           , img 
               [ src "ASSET_URL:../assets/soldier.jpeg?width=250&quality=50" ] 
               [] 
           ]

Behind the hood, it will generate new URL('soldier.jpeg?width=250&quality=50', import.meta.url) for the asset. Refer parcel docs

Do not generate URLs dynamically like

photo : String
photo = "ASSET_URL:" ++ "../assets/jane-doe.jpeg"

photo2 : Bool -> String
photo2 canPickHuman = "ASSET_URL:" ++ 
    ( if canPickHuman then 
        "../assets/john-doe.jpeg"
      else 
        "../assets/dog.jpeg"
    )

photo3 : Bool -> String
photo3 canPickHuman = 
    ( if canPickHuman then 
        "ASSET_URL:../assets/john-doe.jpeg"
      else 
        "ASSET_URL:../assets/dog.jpeg"
    )

Recommended way

johnDoe : String
johnDoe = "ASSET_URL:../assets/jane-doe.jpeg"

dog : String
dog = "ASSET_URL:../assets/dog.jpeg"

smallDog : String
smallDog = "ASSET_URL:../assets/dog.jpeg?width=250&quality=50"

dynamicallyPickImageSrc : Bool -> String
dynamicallyPickImageSrc canPickHuman = 
    ( if canPickHuman then 
        johnDoe
      else 
        smallDog
    )

makeImage : Bool -> Html msg 
makeImage canPickHuman = 
    img [ src (dynamicallyPickImageSrc canPickHuman) ] []