Model for application with list records


I am working on a toy app to track job applications. I have this model:

type alias Application a =
    { company : String, date : String, applications : List a }

That is not working because List a should be List Applications but I cannot do recursive type alias.

I am trying to have a model that can 1) keep track of the updating application (onInput) 2) add the final updated application to a list of applications what would be the best data structure for that?

I was thinking something like {model, List model} should be the way to go, but I am not sure what is the elm way of doing that. Maybe I need 2 types? I tried but then I struggle having to pass 2 models to the update function (as the update function only can output 1 model).


I’m not sure whether I understood correctly, but here’s what I would do:

You want to handle applications. They contain the company and a date. So there’s this type that everything revolves around:

type alias Application =
    { company : String, date : String }

Then your app wants to curate a list of these, so:

type alias Model = List Application

Now, you also need to keep track of what the user has input so far for the company and for the date. This leaves you with:

type alias Model =
    { companyInput : String
    , dateInput : String
    , applications : List Application

I think you tried to reduce duplication of the strings, where there was none. They are two different things, actually! I know that sometimes this can be really hard to spot, so don’t worry. It happens to me all the time. :wink:


That was it! It worked. One thing that is happening now is that I have to click the “+” (add) button 2 times, does this have to do with the way coded the update function?

The code is here:

Also, for future reference I’ll be adding some comments to the code above for anybody who wants to play with a model that also includes a list of records.


I don’t know what you mean by pressing add two times. For me it works as expected.

One thing I noticed is that you add an empty application ([Application "" ""]) to your model. You could also simply use an empty list ([]).

closed #5

This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.