All functions to which the file path of the project was previously passed are now assigned the repository ID instead:
// Without repository mode:
LL.Design(LlProject.List, "C:\Reports\Invoice.lst")
// With repository mode — also applies to Export() and/or Print():
LL.FileRepository = new MyCustomRepository(…);
LL.Design(LlProject.List, "repository://{53F875F0-6177-8AD5-01B44E3A9867}")
In repository mode, "files" become "repository items", and filenames become "repository IDs". In addition to its ID, each repository item possesses a type, a time stamp, and a descriptor (string with variable length which contains internal information). Hence, in addition to the file content, your repository implementation will also need to be able to save and retrieve at least these four pieces of information for each repository item.
You will find a simple repository implementation in the ASP.NET sample projects (class SQLiteFileRepository) which provides a repository with an SQLite database for data storage.
For detailed descriptions of the methods to be implemented in the IRepository interface, please refer to the .NET online help (combit.ListLabel29.chm).