Extreme Programming Installed

Model First

When you're creating a GUI, you should develop and test the model first. We'll assume this has been done and that it has the following interface:

               public class SearcherFactory {
                   public static Searcher get(String s)
                           throws IOException {...}
               }

               public interface Searcher {
                   public Result find(Query q);
               }

               public class Query {
                   public Query(String s) {...}
                   public String getValue() {...}
               }
               public interface Result {
                   public int getCount();
                   public Document getItem(int i);
               }

               public interface Document {
                   public String getAuthor();
                   public String getTitle();
                   public String getYear();
               }

In testing and developing the GUI, I don't mind depending on the interfaces of the model; I'm less happy when I have to depend on its concrete classes.