programWithFlags with Dict or alternative

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1

Hello,
I’d like to use Html.programWithFlags to pass a JS object to Elm. I figured that a Dict type best represents what I’m passing to Elm, but I got across this message when trying to make it work:

Your `main` is demanding an unsupported type as a flag.

The specific unsupported type is:

    Dict String String

The types of values that can flow through in and out of Elm include:

    Ints, Floats, Bools, Strings, Maybes, Lists, Arrays, Tuples, Json.Values,
    and concrete records.

Here is the code: https://ellie-app.com/32gqyWf5V5Va1

The flags I’m passing is an object with lots of keys, holding translations (strings). Using a Dict would be convenient since I don’t want to list every single field as String in Elm (is this bad practice?).

What’s the best way to solve this? Thanks!

2

You can get whatever type you want by using a manual JSON Decoder. See this ellie:

https://ellie-app.com/32gKHPMsYVra1

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3

You can pass in a List (String, String) and pass that to Dict.fromList before saving to your model.

https://ellie-app.com/32gMD8rqknMa1

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4

Awesome, thank you @gampleman @lydell for the solutions!

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