title: undefined method `model_name' for Project:Class
body: <p>I've looked through all the related questions but nothing's new for me here.</p>
  
  <p>I have a Project controller with "new" action</p>
  
  <pre><code>class ProjectsController &lt; ApplicationController
    def new
      @newproject = Project.new
    end
  end
  </code></pre>
  
  <p>Project is a simple class, not active record:</p>
  
  <pre><code>class Project
    attr_accessor :name, :description
    def initialize
      @name = ""
      @description = ""
    end
  end
  </code></pre>
  
  <p>I get the error "undefined method `model_name' for Project:Class"</p>
  
  <p>This is an erb file sample:</p>
  
  <pre><code>&lt;%= form_tag(@newproject)  do |f| %&gt;
    &lt;%= f.label :name %&gt;:
    &lt;%= f.text_field :description %&gt;&lt;br /&gt;
  &lt;% end %&gt;
  </code></pre>