Question

I have two model classes: Goal and Objective. A Goal has many Objectives, and an Objective belongs to one Goal.

I have created a page for creating a new Objective via a form. In the page’s controller, I am setting the value of a variable @default_goal like so:

@objective = Objective.new

if params.has_key?(:default_goal)
    @default_goal = Goal.find(params[:default_goal])
end

Then, in my form I want to make that variable the default Goal in an association dropdown list. I tried the following but it doesn’t seem to work:

<%= simple_form_for @objective do |f| %>
    <%= f.association :goal, :prompt => "Select a goal", :default => @default_goal %>
<% end %>

How can it be done?

Answer 1

Ah, the answer was really obvious. Instead of setting the default in the view form, it should be done on the record itself in the controller. Example:

@objective = Objective.new

if params.has_key?(:default_goal)
    @objective.goal = Goal.find(params[:default_goal])
end

That will automatically select it as the default option in the view form’s association list.