Data layer

In this section you are required to decide and describe how the data will be stored for persistence in your application. Recommended options are to use a database or XML. Other structured data storage can be used if accompany with convincing justification.

Throughout this section, always describe:

• Queries and updates (for a database).
• Relevant tags and tag's attributes (for XML).
• Exact way of parsing (for any other solution).

Give in this section:

1. A short description of your chosen solution for storage.
2. Which tools you are intended to use - database engine, XML parser, etc.
3. The Format used for storage according to the selected solution:
   • Database scheme for a database.
   • Tags and attributes definition for XML (can be DTD or schema).
   • Format description for any other solution.
4. A class diagram describing the classes in the data layer and their relations with other classes.
5. A sequence or collaboration diagrams describing the following:
   1. Adding a new item to a library or storing an entire library, according to you solution.
   2. displaying and editing an item's attributes.
   3. Loading a library.
6. Describe how reports about the data will be generated and displayed.