title: How to skip a session create?
body: <p>When a <code>nil</code> user clicks "sign up" he is encouraged to submit a goal, habit, and value before being logged in.</p>
  
  <p>But he may skip one of those forms by clicking:</p>
  
  <p><a href="https://i.stack.imgur.com/SV94V.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SV94V.png" alt="enter image description here"></a></p>
  
  <p>The problem is if he skips a form right now then an error message pops up:</p>
  
  <pre><code>TypeError in UsersController#create
  no implicit conversion of nil into String
  </code></pre>
  
  <p>In this example I skipped the habit form so it is being raised on <code>@user.habits.create(</code></p>
  
  <p><strong>users_controller</strong></p>
  
  <pre><code>  def create
      @user = User.new(user_params)
      if @user.save
        # Goals
        name = session.delete(:goal_name)
        deadline = session.delete(:goal_deadline)
        # Values
        vname = session.delete(:valuation_name)
        vimage = session.delete(:valuation_image)
        # Habits
        date_started = session.delete(:habit_date_started)
        committed = session.delete(:habit_committed)
        trigger = session.delete(:habit_trigger)
        action = session.delete(:habit_action)
        target = session.delete(:habit_target)
        reward = session.delete(:habit_reward)
        missed_days = session.delete(:habit_missed_days)
        # Create
        @user.habits.create(date_started: Date.parse(date_started), committed: committed, trigger: trigger, action: action, target: target, reward: reward, missed_days: missed_days).create_with_current_level
        @user.goals.create(name: name, deadline: deadline)
        @user.valuations.create(name: vname, image: vimage)
        @user.send_activation_email
        redirect_to root_url
      else
        render 'new'
      end
    end
  </code></pre>
  
  <p>How can we allow the user to skip? I've been trying to include various <code>if/else</code> statements, but I'm having a hard time setting the right method to trigger the conditional.</p>