Can anybody explain the concept of pluggable adapter to me with good example? - language-agnostic

Question

Can anybody explain the concept of pluggable adapter to me with good example?

Answer 1

From what I understood from a quick reading of Google results, a pluggable adapter is an adapter that isn't hard-coded against a specific adaptee. On the surface (the adapter's own interface), it's all the same but it can adapt to different adaptees with different interfaces. I found this thread pretty explanatory:
Basically, it allows you to put in an
adapter when the adaptee (receiver)
protocol is not known at compile time
by using reflection. When you create
the adapter instance, you pass it the
name of the adaptee's method to call,
and also any metadata that's necessary
to translate input types. When the
adapter receives a method call of the
target interface, it uses reflection
to call the corresponding method
specified on the adaptee.
And this:
The main responsibility of the Viewer
is to populate a widget from a domain
model without making any assumptions
about domain itself. JFace viewer uses
the Delegating Objects mechanism in
Pluggable Adapter Pattern to implement
the above requirement.
Think of it as a facehugger from Alien; when it hugs a face, all you see is the slimy back of the facehugger. You can poke it with a stick and try to pry off its arms (the adapter interface). But it basically can hug the face of any human (the adaptee), regardless of the face features. Maybe I'm pushing it a bit, but, hey, I love Alien.

Answer 2

You can read this article about adapter/pluggable pattern:
Table of content in this article:
* 1 Design Patterns
* 2 Intent of Adapter
* 3 Motivation
* 4 Structure
* 5 Applicability
* 6 Consequences
* 7 Implementation
o 7.1 Known Uses and Sample Code
o 7.2 Related Patterns
* 8 Conclusions
* 9 Appendix
o 9.1 References
o 9.2 Glossary
Quote:
Smalltalk introduced the concept of a
"pluggable adapter" to describe
classes with built-in interface
adaptation. This interesting concept
allows for classes to be introduced
into existing systems that might
expect different interfaces to the
class. This technique can help promote
class reuse across modules and even
projects.
Here is a small example:
We have two classes - Foo & Boo that outputs some string to console. Adapter class can adapt methods from both classes to provide interface (SaySomething) required by client. Note that there is no dependency on interface name - we can easily adapt both SayHey and Bark methods.
class Foo
{
public static void SayHey() { Console.WriteLine("Hey!"); }
}
class Boo
{
public static void Bark() { Console.WriteLine("Woof!"); }
}
class Adapter
{
public Action SaySomething { get; private set;} // "pluggable" adapter
public Adapter(Action saySomethingAction)
{
SaySomething = saySomethingAction;
}
}
class Program
{
static void Main(string[] args)
{
(new Adapter(Foo.SayHey)).SaySomething();
(new Adapter(Boo.Bark)).SaySomething();
}
}

Answer 3

A distinguish Feature of the Pluggable Adapter is that the method called by the client and the method existing in the interface can be different.
interface Ilegacy
{
float calculate(int a, int b);
}
class Legacy : Ilegacy
{
public float calculate(int a, int b)
{
return a * b;
}
}
class Adapter
{
public Func<int, int, float> legacyCalculator;
public Adapter()
{
this.legacyCalculator = new Legacy().calculate;
}
}
class Client
{
static void Main()
{
float result = new Adapter().legacyCalculator(5, 6);
}
}
This can normally acheived with the use of delegate,Func or Action in C#