title: Rails: Custom Validation :on => :update Running During :create
body: <p>I have the following in my controller:</p>
  
  <pre><code>def create
    group = Group.create(params[:group])
  end
  </code></pre>
  
  <p>And this in my model:</p>
  
  <pre><code>validate :governance_style_change, :on =&gt; :update
  
  . . . .
  
  private
  
    def governance_style_change
      if self.governance_style_was != 3
        errors.add(:governance_style, I18n.t("group.errors.cannot_change_governance_style"))
      end
    end
  </code></pre>
  
  <p>For some reason, the validation is running during <code>create</code>. Have I done something wrong?</p>