In this final entry in the 5 part ABAP OO series, we examine examples of how SAP puts the techniques that we learned in the previous 4 sessions to work within the standard code that they deliver to customers. We start by looking at the CL_BCS classes for sending email. CL_BCS* serves as a perfect example of the use of Persistent Objects and Polymorphism. We also look at the functionality behind the new ABAP Code Completion feature in the ABAP Editor. This block of code uses Persistent Objects, Inheritance/Polymorphism, Exception Classes, and MVC structured Classic Dynpro.
This is part 4 of the 5 part series on ABAP OO. In this part, we look at the special use case of Object Oriented technology and design techniques as they are applied to User Interface creation. Throughout all the ABAP UI technologies we study how MVC (Model View Controller) design can be applied. We look briefly at BSP and Web Dynpro ABAP and OO effects the overall design as well as specific features like UI element rendering and eventing. We close with an example of how you can adapt even Classic Dynpro and its PBO/PAI processing looks to a more Object Oriented MVC flow.
This is part 3 of the 5 part series on ABAP OO. In this part we will expand the lessons of the previous tutorial and look at a special type of class in ABAP – the Persistent Object. Persistent Objects are an OO-based approach to the types of data access that you would normally perform with SQL statements. With Persistent Objects you don’t code any SQL statements. Instead a class is generated for you that contains SET and GET methods for reading and updating data. ABAP Persistent Objects also contain the functional for more complex update scenarios – like V2 Asynchronous updates.
This is part 2 of the 5 part series on ABAP OO. In this part we will expand the lesson by looking at static vs. instance, visibility, exception classes, inheritance, polymorphism and abstract classes. We start with a very basic class with only static methods that works very much like a Function Group/Function Modules. Next we change the methods into instance methods and see how a class instance allows us to model complex data structures and relationships in code. Then we see how exception classes can make our exceptions more meaningful and simplify the surrounding code for dealing with exceptions. Finally we see the real power of object oriented design come to life as we use inheritance and polymorphism to hide the inner complexity of our business logic from calling applications all while ensuring uniform execution of our code. These techniques may feel foreign at first, but in the long run they lead to code that is easier and safer to maintain.
This week we begin a 5 part series based upon a frequent request – to look at basic ABAP Object Oriented concepts. Throughout this series we will look at OO terminology, development tools, and design patterns that span a variety of ABAP release levels. We will try to keep the discussion away from all the new cutting edge syntax so that it is still quite usable for those of you on older releases like 4.6C or 6.20.
For the 5 part series we will start with Part 1 looking at tooling (the ABAP Class Builder) and some basic terminology. In Part 2 we will expand the lesson by looking at static vs. instance, visibility, exception classes, inheritance, polymorphism and abstract classes. In part 3 we will see how a special type of class, called a persistent object, can be used for Object Oriented access to the database. In part 4 we will explore Object Oriented concepts in User Interface technologies. Keeping with the theme of older release levels, we will focus this part on using Model View Controller and OO eventing within Classic Dynpro applications. Finally in part 5 we will look at real world, complex example that uses all the techniques and technologies from the previous parts.
