title: How I lists polymorphic with different model together in rails?
body: <p>Here I have 3 different models 
     <br>1.Category
     <br>2.Branch
     <br>3.Product</p>
  
  <p>The Category model has many branches, And the Branches has many different products.</p>
  
  <p><p>And each of them has comments with polymorphic model commentable.</P></p>
  
  <p>Here is my question. 
  How can I make products' comments also can be seen in its branch view? And mixed with branches' comments sorting by updated date?</p> 
  
  <p>ex. 
  <br>procuct1 has comment1 updated in 5/1
  <br>branch1 has  comment2 in 5/2
  <br>and product2 has comment3 in 5/3</p>
  
  <p>And in my branch1 view. I can see all the above comments in sequence.
  <br>comment1
  <br>comment2
  <br>comment3</p>