title: unknown attribute: uploaded_file - Rails 4
body: <p>Rails 4
  Ruby 2.0
  Windows 8.1</p>
  
  <p>In my view, I have the following:</p>
  
  <pre><code>&lt;%= f.file_field :uploaded_file, label: "Image" %&gt;
  </code></pre>
  
  <p>And in my controller, I have the following:</p>
  
  <pre><code>  def create
      @agent = Agent.new(agent_params)
      ........
    end
  
      def agent_params
        params.require(:agent).permit(:uploaded_file, :first, :last, :email)
      end  
  </code></pre>
  
  <p>When I try to create an agent, I get the following error message:</p>
  
  <pre><code>    unknown attribute: uploaded_file
  </code></pre>
  
  <p>and it points to this line of code:</p>
  
  <pre><code>@agent = Agent.new(agent_params)
  </code></pre>
  
  <p>uploaded_file is in the list of permitted params and I can see it in params (looking through the log file). Any ideas?</p>