How to have a drop down <select> field in a rails form?

Question

I am creating a scaffold -

rails g scaffold Contact email:string email_provider:string 

but I want the email provider to be a drop down (wi

Answer 1

You create the collection in the Contact controller -

app/controllers/contacts_controller.erb 

Adding

@providers = Provider.all.by_name

to the new, create and edit methods, using a scope for the by_name in the Provider model - app/models/provider.rb - for the ordering by name

scope by_name  order(:name)

Then in the view - app/views/contacts/_form.html.erb - you use

<%= f.collection_select :provider_id, @providers, :id, :name, include_blank: true %>

For rails forms, I also strongly recommend you look at a form builder like simple_form - https://github.com/plataformatec/simple_form - which will do all the heavy lifting.