Football Demonstration Application

This application uses similar styles to Restaurant in terms of tabbed pages, lookups etc, but it's worth looking at the way page pre-population is handled.

Input

Main class diagram

Create match diagram

View league table diagram

Model

football.mdl    Rational Rose file

Output

football.zip    99.8% generated.

See It Running

Application running

Description

The best example is for the Show Table event (in the View Table diagram). Let me draw your attention to the code behind the event, which calculates the league table dynamically, and stores it ready for the next page to display it. This could have been handled as a call to a session method (and in retrospect probably should have been). Nevertheless the techniques to manipulate the data are quite interesting, as the database is not as solidly connected as it might seem.

The first thing to notice when tackling code for an event like this is that the next page, the one we are preparing the data for has two connected dataviews. The primary dataview is LeagueTableDV and this is related to ClubResultsDV. Dataviews have value objects associated with them (called by the name of the dataview with a suffix of Info). It is these value objects that are picked up by a page, and the values displayed. The value objects of related dataviews, such as these, each have variables, and associated getters and setters of a type of the other. The variable in LeagueTableInfo is actually of type Collection as the relationship is to-many. This allows many instances of ClubResultsInfo to be associated with one LeagueTableInfo instance.

The first line ArrayList arrayList = (ArrayList) getCollectionSettings(); returns an ArrayList containing the value object associated with the selection of the previous page. This is the maintenance value object for the league table record, which points to the same entity as LeagueTableDV, and also has connectivity to the Game entity, which stores the match results.

The line lvo = (new LeagueDataViewSessionRD()).populateValues(lvo); adds associated data values, including those of the Games for that particular league.

After plenty of calculations for each club for which we have results, we have built of a collection of ClubResultsDVInfo objects, these are then inserted in descending points order into an ArrayList, which is in turn set as the Collection in the LeagueTableDVInfo object. This is stored using the call to store(ltvo), one of a series of methods that lets the application programmer manipulate data from and for pages.