Ruby on Rails: Nested form with Existing Objects

Question

I want to create a nested form in Ruby on Rails. Let's say I have a Model Player and a Model Achievement.

In a form for the User I want to assign n Achievements to the User. The Achievements have been created before, so they exist when the Achievements get assigned. How do I do that? How should the View, the Controller and the Models look like? I searched for hours but I didn't find anything.

I'd like to realize it with a select field, with which the Achievements get selected.

Answer 1

there is quite a few examples out there and depending which form are you using you can choose:

• https://stevepolito.design/blog/create-a-nested-form-in-rails-from-scratch/
• https://levelup.gitconnected.com/the-many-things-about-nested-form-in-ruby-on-rails-15f32ed66446
• https://tudip.com/blog-post/the-implementation-of-nested-forms-in-ruby-on-rails-fields-for/#:~:text=Rails%20provide%20a%20powerful%20mechanism,the%20parent%20on%20associated%20records.

you can also use simple_forms https://github.com/heartcombo/simple_form which will automatically create a select field for the achievements (you can check their documentation) and this might help How should I use rails and simple_form for nested resources?