form_for instance model help; move logic from form to controller

rubyonrails-talk
1 
I have this form, everything works fine, but I would like to move the current_user.relationships.build logic to the controller.

<%= form_for(current_user.relationships.build(followed_id: @user.id)) do |f| %>
  <div><%= f.hidden_field :followed_id %></div>
  <%= f.submit "Follow", class: "btn btn-large btn-primary" %>
<% end %>



Controller Relationships create method

def create
    @user = User.find(params[:relationship][:followed_id])
    current_user.follow!(@user)
    redirect_to @user

end
2

so if in your action you do

@relationship = current_user.relationships.build(followed_id: @user.id)

you should have a variable called relationship on your view:

<%= form_for(relationship) do |f| %>
  <div><%= f.hidden_field :followed_id %></div>
  <%= f.submit "Follow", class: "btn btn-large btn-primary" %>
<% end %>