The Adapter pattern allows classes to work together that normally could not because of incompatible interfaces. It converts the interface of a class into another interface that a client expects. Adapters are used to make existing classes work with others without modifying their code by acting as a bridge between incompatible interfaces. Some examples include data adapters that allow different data sources to work with datasets and .NET using runtime callable wrappers as adapters between .NET code and COM objects.

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