title: Connection between model, view and controller
body: <p>I've searched a lot and read a lot about the concept of MVC. But I still don't know how to connect them together. Suppose I have a controller class, view class and model class. If user did something in that view, view should notify controller the action and controller may need to communicate with model to get some data. </p>
  
  <ol>
  <li>Now, does view hold a reference to the controller? Does the controller has a property of that model? Or they just using like "include"?</li>
  <li>The data is saved in memory, or database? Memory means stored in variables. </li>
  <li>More complicated case, one action from user may need many controllers and models involved. How to co-ordinate them together?</li>
  </ol>
  
  <p>What I've done before is I create a "view controller", which has view and some actions of that view. 
  And sometimes there is no model. All data is passed by parameter. If there are some models, some of them are singleton so I can get it everywhere. </p>