Ever called tech support and been passed from one agent to another until someone finally fixes your problem? That’s exactly what the Chain of Responsibility Pattern is all about—it creates a hotline of handlers where each one gets a chance to deal with a request. If one can’t help, the call gets forwarded to the next in line until your issue is resolved.
Why Bother with It?
- Smooth Escalation: Just like tech support, your request is handled by the right expert without overwhelming a single person or component.
- Decoupled Request Handling: Each handler only cares about its own expertise. If it can’t solve your problem, it passes it on—no one gets bogged down.
- Flexibility and Reusability: Easily add or remove support levels without rewriting your entire help desk (or code). The chain remains intact even as your system grows.
How It Works (In Plain English)
- The Call Center Setup: Think of your system as a call center with multiple support levels (Level 1, Level 2, Level 3, etc.).
- Handling the Call: When a request comes in, it goes to the first support agent. If they can handle it, great! If not, they pass it to the next available agent.
- Escalation on Demand: The request keeps moving along the chain until it reaches an agent who can resolve the issue—or it goes unhandled if no one can help.
- No Overlap, Just Efficiency: Each agent deals with their specific type of problem, keeping the process neat and efficient.
C# Code Example
using System;
// Handler interface: Defines a method for setting the next handler and handling the request.
public interface ITechSupport
{
ITechSupport SetNext(ITechSupport handler);
void HandleRequest(string issue);
}
// Base class for common functionality
public abstract class TechSupportBase : ITechSupport
{
private ITechSupport _nextHandler;
public ITechSupport SetNext(ITechSupport handler)
{
_nextHandler = handler;
return handler;
}
public virtual void HandleRequest(string issue)
{
if (_nextHandler != null)
{
_nextHandler.HandleRequest(issue);
}
else
{
Console.WriteLine("Issue could not be resolved. Please try again later.");
}
}
}
// Level One Support: Handles basic issues.
public class LevelOneSupport : TechSupportBase
{
public override void HandleRequest(string issue)
{
if (issue.Contains("password") || issue.Contains("login"))
{
Console.WriteLine("Level One: Issue handled - " + issue);
}
else
{
base.HandleRequest(issue);
}
}
}
// Level Two Support: Handles intermediate issues.
public class LevelTwoSupport : TechSupportBase
{
public override void HandleRequest(string issue)
{
if (issue.Contains("crash") || issue.Contains("error"))
{
Console.WriteLine("Level Two: Issue handled - " + issue);
}
else
{
base.HandleRequest(issue);
}
}
}
// Level Three Support: Handles advanced issues.
public class LevelThreeSupport : TechSupportBase
{
public override void HandleRequest(string issue)
{
Console.WriteLine("Level Three: Issue handled - " + issue);
}
}
// Client Code
public class Program
{
public static void Main()
{
// Set up the chain of responsibility
ITechSupport levelOne = new LevelOneSupport();
ITechSupport levelTwo = new LevelTwoSupport();
ITechSupport levelThree = new LevelThreeSupport();
levelOne.SetNext(levelTwo).SetNext(levelThree);
// Different issues coming into the system
Console.WriteLine("Request 1: 'Forgot my password'");
levelOne.HandleRequest("Forgot my password");
Console.WriteLine("\nRequest 2: 'Application crash on startup'");
levelOne.HandleRequest("Application crash on startup");
Console.WriteLine("\nRequest 3: 'Unknown system failure'");
levelOne.HandleRequest("Unknown system failure");
}
}
The Takeaway
The Chain of Responsibility Pattern is like having a well-organized tech support hotline. Each level handles what it’s best at, passing on the call until someone can resolve the issue. This design keeps your code decoupled and flexible—just like a smooth escalation process in a customer support center. Next time you need to manage a series of handlers, think of your own tech support hotline and let the chain do its magic!
Happy coding—and may your issues always be handled efficiently!