How can a default value be set for a form.combobox tag?

[csalmeida]

Hi 👋

I am currently trying to use form.combobox outsite of the context of a specific model and pass a default value to it.
What I mean by default is that for example on a text_input we can pass :value to it:

<%= form.text_field :company, value: params[:company], class: "input" %>

Is it possible to do the same with the combobox like so?

<%= form.combobox :location, Country.all, value: params[:location] %>

I noticed in the "A prefilled combobox" section in the documentation there's a way of assigning a pre-selected value by using a method? I didn't really understand that way but what I would like is to decide what the value would be myself if possible.

Usually the combobox was able to work this out because I was using the following pattern:

<%= form_with model: model do |form| %>

However, now I am using a form with no model attached to it, it's purpose is to render inputs to filter a collection:

<%= form_with url: search_employers_path, method: :get do |form| %>

I also think that the component might accept :value but it's not working in my case:
https://github.com/josefarias/hotwire_combobox/blob/main/app/presenters/hotwire_combobox/component.rb#L28

My goal is to pull the :location from the parameters, which is an ID for a row in a database that points to a Country and use that value from params[:location] to have that option selected on render.

I have attached a video below where we can see that when the form is submitted the selected value is cleared.

Is there a way to set the value or is there a better way of achieving this?
Any tips or feedback would be deeply appreciated. 🙏

CleanShot.2024-05-16.at.19.50.25.mp4

[csalmeida]

Okay, I think I was missing something on my side, after reading a bit more of the source code it did seem like combobox could take a :value parameter.

Then I found this in the documentation which made me think that maybe the :value needs to be an integer by default:

ActiveRecord::Relation: the display is obtained by calling #to_combobox_display on each object and the value is obtained by calling #id.

This change fixed it (params[:location].to_i):

<%= form.combobox :location, Country.all, id: "location", label: nil, value: params[:location].to_i %>

Here's a demo where the value is being picked from params[:location] and it loads correctly:

CleanShot.2024-05-17.at.11.17.14.mp4

[josefarias]

Great digging! I'll reopen this so I remember to consider casting the value so you don't have to do that yourself.