How do I save an association in a controller?

Question

Trying to accomplish creating an association from the controller and I can't quite get it. Why wouldn't this work?

@document.components = @components.first if @document.automatic_component_selection?

Answer 1

Based in your comment then you have two options:

• @document.components << @components.first if @document.automatic_component_selection?
• @document.components.create!(@components.first) if @document.automatic_component_selection?

What you are doing with @document.components = @components.first makes the collection contain only the supplied objects, by adding and deleting as appropriate.

Reference: Rails Guides Active Record Association s

Answer 2

I believe you're trying to add @components.first to that Document object's associated components. In that case, you can write

@document.components << @components.first if @document.automatic_component_selection?