Database API

The program uses the Database class as a factory to create, load and save semesters. It essentially handle the XML parsing and writing of the files describes above, and the generation of Semester object. The Database class provide the following functions:

• createSemester(): Create a new semester directory in the database, copy the list of courses of the last semester existing in the database, and return a Semester object containing the list of courses.
• loadSemester(): Load the content of a semester directory into a Semester object, and return it.
• saveSemester(): Write the data of a Semester object into the corresponding directory in the database.