The document explains the adapter pattern, which connects incompatible interfaces, allowing classes to work together. It describes how adapters change the interface of existing objects and supports system extensibility through new concrete adapters. Real-world examples include using adapters in .NET for legacy COM objects and various data adapter classes for integrating different data sources.

1. Adapter Pattern
Shahriar Iqbal Chowdhury & Monjurul Habib
Code Name: Remington
http://www.facebook.com/groups/netter/

2. What is Adapter
• A device for connecting pieces of equipment that
cannot be connected directly
• An adapter allows classes to work together that
normally could not because of incompatible
interfaces

3. Missing something??

4. How does it work?

5. When we need?
• Convert the interface of a class into another
interface that client expects.
• Allow classes to work together that couldn’t
because of incompatible interfaces.
• Future clients can be satisfied through the creation
of additional concrete Adapter.
• Adapter is meant to change the interface of an
existing object.
• A way to achieve OCP(Open/Closed Principle)

6. Client Component

7. Client
Adapter
Component/
Adaptee

8. Adapters in the real world

9. UML Structure

10. Way to use (ref. DoFactory)

11. Client

12. Adapter

13. Adaptee

14. Another shocking example

15. Adapter @.NET Framework
• From .NET-based code you can easily call legacy COM
objects and vice versa.
• Behind the scenes, Visual Studio® .NET create a Runtime
Callable Wrapper (RCW) class. Inside the RCW, .NET specific
format is converted into a format that the COM component
expects and vise versa.
• Data Adapters adapts data from different source (SQL
Server, Oracle, ODBC, OLE DB) to dataset.
• Different Data Adapter classes are used
SqlDataAdapter
OdbcDataAdapter
OleDbDataAdapter

16. Real World Scenario’s
• Most of the applications using third party libraries
use adapters as a middle layer between the
application and the 3rd party library.
• Memory card reader software