title: Components, Extension or Module in Yii 2?
body: <p>I am new to yii and using version 2. I developed a project which uses a library (I coded) for parsing a CAD model file, extract vertexes, edges, faces etc, finally combine those entities to display the model and then extract features. It displays the model using the three.js library. A user has to be signed-in in order to upload the model file and do all this stuff. I would like to refactor the app into version 2 using the yii 2 framework. So I would like to know how I can merge the feature recognition library into the yii app, should I create a Components, Extension or Module or use other means?</p>
  
  <p>The library is coded in plain OOP. I access it by requiring an <code>init.php</code> file which requires about 20 library class files. If I create a module for the library the view will draw the model but where do the parser and feature extractor go in the model or controller files?</p>
  
  <p>Thanks in advance.</p>