title: How to Inflection a string to a model name in Rails?
body: <p>There is one <code>http://localhost:3000/me/posts/new?type=note</code></p>
  
  <p>I want to create a model by the params <code>type</code>in my controller and I have a model named Post::Note.</p>
  
  <p>so how to create it by params[:type] string ?</p>