mirror of
https://github.com/JakubVojvoda/design-patterns-cpp.git
synced 2025-12-17 12:54:36 +03:00
fix directory name
This commit is contained in:
87
chain-of-responsibility/ChainOfResponsibility.cpp
Normal file
87
chain-of-responsibility/ChainOfResponsibility.cpp
Normal file
@@ -0,0 +1,87 @@
|
||||
/*
|
||||
* C++ Design Patterns: Chain of Responsibility
|
||||
* Author: Jakub Vojvoda [github.com/JakubVojvoda]
|
||||
* 2016
|
||||
*
|
||||
* Source code is licensed under MIT License
|
||||
* (for more details see LICENSE)
|
||||
*
|
||||
*/
|
||||
#include <iostream>
|
||||
|
||||
/*
|
||||
* Handler
|
||||
* defines an interface for handling requests and
|
||||
* optionally implements the successor link
|
||||
*/
|
||||
class Handler {
|
||||
public:
|
||||
virtual void setHandler(Handler *s) {
|
||||
successor = s;
|
||||
}
|
||||
|
||||
virtual void handleRequest() {
|
||||
if (successor != 0) {
|
||||
successor->handleRequest();
|
||||
}
|
||||
}
|
||||
// ...
|
||||
|
||||
private:
|
||||
Handler *successor;
|
||||
};
|
||||
|
||||
/*
|
||||
* Concrete Handlers
|
||||
* handle requests they are responsible for
|
||||
*/
|
||||
class ConcreteHandler1 : public Handler {
|
||||
public:
|
||||
bool canHandle() {
|
||||
// ...
|
||||
return false;
|
||||
}
|
||||
|
||||
virtual void handleRequest() {
|
||||
if (canHandle()) {
|
||||
std::cout << "Handled by Concrete Handler 1" << std::endl;
|
||||
} else {
|
||||
std::cout << "Cannot handle by Handler 1" << std::endl;
|
||||
Handler::handleRequest();
|
||||
}
|
||||
// ...
|
||||
}
|
||||
// ...
|
||||
};
|
||||
|
||||
class ConcreteHandler2 : public Handler {
|
||||
public:
|
||||
bool canHandle() {
|
||||
// ...
|
||||
return true;
|
||||
}
|
||||
|
||||
virtual void handleRequest() {
|
||||
if (canHandle()) {
|
||||
std::cout << "Handled by Handler 2" << std::endl;
|
||||
} else {
|
||||
std::cout << "Cannot handle by Handler 2" << std::endl;
|
||||
Handler::handleRequest();
|
||||
}
|
||||
// ...
|
||||
}
|
||||
|
||||
// ...
|
||||
};
|
||||
|
||||
|
||||
int main()
|
||||
{
|
||||
ConcreteHandler1 handler1;
|
||||
ConcreteHandler2 handler2;
|
||||
|
||||
handler1.setHandler(&handler2);
|
||||
handler1.handleRequest();
|
||||
|
||||
return 0;
|
||||
}
|
||||
12
chain-of-responsibility/README.md
Normal file
12
chain-of-responsibility/README.md
Normal file
@@ -0,0 +1,12 @@
|
||||
## Chain of Responsibility
|
||||
|
||||
Chain of Responsibility pattern avoids coupling the sender of a request to its receiver
|
||||
by giving more than one object a chance to handle the request. The pattern chains
|
||||
the receiving objects and passes the request along the chain until an object handles it.
|
||||
It has a behavioral purpose and deals with relationships between objects.
|
||||
|
||||
### When to use
|
||||
|
||||
* more than one object may handle a request, and the handler should be ascertained automatically
|
||||
* you want to issue a request to one of several objects without specifying the receiver explicitly
|
||||
* the set of objects that can handle a request should be specified dynamically
|
||||
Reference in New Issue
Block a user