The program we just wrote is structured according to TEA (The Elm Architecture), which should make it easy to extend. To begin, we might alter the representation of our model so that it can store more than just a single string.
Instead, let’s use a record. Much like a JSON object, Elm records store values for a number of keys. Let’s move our model’s string into a record key, so that we can later add more keys with other values as needed.
Change the Model to a record, like this:
type alias Model = {
message: String
}
Create a function called initialModel that returns a record that conforms to the type above, to be used as the program’s initial state. Add a function signature to initialModel.
A concrete record of this type could look like this:
{ message = "Hello" }
In init, call initialModel to obtain the initial model, rather than using a hard-coded value.
Change the view so it uses model.message to get the text to be displayed in the user interface.