Defining the Comment, Reply, Photo, and Page Models

You should always look at the object model needs as the first step in implementing an application. In this example, the goal is to allow users to add comments to webpages. To do so, you first need to identify objects that users can add comments to. This example provides a webpage that contains several photos. You will take advantage of reusability as you enable users to attach comments to both the webpage and individual photos. You need a model for the pages and a model for the photos to provide objects to attach the comments to. The following sections discuss the designs of the model schemas.