ASP.NET 3.5 Enterprise Application Development with Visual Studio® 2008: Problem - Design - Solution

3.4. Summary

This chapter focused on the business logic layer and created the base classes used throughout the rest of the book. There are two types of business objects in the BLL: static business objects, which cannot have their data changed by the user, and edit objects, which include functionality for adding, updating, deleting, and selecting records from the DAL. Transactions are started and committed in the BLL and objects can either enlist in an existing transaction or start a new one.

Keep in mind two key points regarding communication between the BLL and the DAL:

• Data retrieved from the DAL is passed back to the BLL as a single entity object, a list of entity objects, or scalar values.

• Data passed to the DAL is passed as scalar values.

The key points to remember for communicating between the BLL and the user interface are as follows:

• The user interface creates instances of business objects and calls the Load method to retrieve the data.

• The user interface creates instances of business objects, sets their properties, and calls either Save to add or update a record, or Delete to delete a record.

• Broken validation rules are passed back to the user interface in the ENTValidationErrors list.

The key points to remember when creating a class that inherits from the ENTBaseBO class are as follows:

• Declare the class as Serializable.

• Create the custom properties for the business object.

• Implement the GetDisplayText method to return the text that should be displayed to the user when viewing ...