Let's say I have a User model, with a facebook_uid field corresponding to the user's facebook id.

I want to allow the user to unlink his facebook account. Do do so, I need to set this attribute to nil.

I currently see 2 ways of doing this

First way : create a custom action and link to it

# app/controllers/users_controller.rb
def unlink_facebook_account
  @user = User.find params[:id]
  # Authorization checks go here
  @user.facebook_uid = nil
  @user.save
  # Redirection go here
end

# config/routes.rb
ressources :users do
  get 'unlink_fb', :on => :member, :as => unlink_fb
end 

# in a view
= link_to "Unlink your facebook account", unlink_fb_path(@user)

Second way : create a form to the existing update action

# app/views/user/_unlink_fb_form.html.haml
= form_for @user, :method => "post" do |f|
  = f.hidden_field :facebook_uid, :value => nil
  = f.submit "Unlink Facebook account"

I'm not a big fan of either way.

• In the first one, I have to add a new action for something that the update controller already can do.

• In the second one, I cannot set the facebook_uid to nil without customizing the update action, and I cannot have a link instead of a button without adding some javascript.

Still, what would you recommend as the best and most elegant solution for this context? Did I miss a third alternative?