Simple Implementation of Abstract Factory Pattern using C++

Introduction

This post describes the simple implementation of Abstract Factory Pattern using C++.

Intent

• Provide an interface for creating families of related or dependent objects without specifying their concrete classes.
• A hierarchy that encapsulates: many possible "platforms", and the construction of a suite of "products".

Problem

We all know about PCI (Peripheral Component Interconnect) and USB ( Universal Serial Bus) communication protocol mechanisms for data transfer. Using this as an example, I have created an abstract interface for both protocols and access their respective methods.

UML Diagram

Background

1. Design Patterns using GOF
2. C++ Programming
3. Mentor - Mr.K.Babu Senior Software Engineer, Qmax Test Equipments Pvt. Ltd.

Code

#include <iostream> 
using namespace std; 
// Abstract product 
class HWProduct
{
public:
    virtual void readData()=0;
    virtual void writeData()=0;
};
//Concrete USB Product
class USBProduct:public HWProduct
{
public:
    USBProduct() {}
    void readData()
    {
        cout << "USB Read"<<endl;
    }
    void writeData()
    {
        cout << "USB
        Write"<<endl;
    }
};

//Concrete PCI Product
class PCIProduct:public HWProduct
{
public:
    PCIProduct() {}
    void readData()
    {
        cout << "PCI Read"<<endl;
    }
    void writeData()
    {
        cout << "PCI
        Write"<<endl;
    }
};

// Abstract Factory
class HardwareFactory
{
public:
    virtual HWProduct* getProduct()=0;
};
// Concrete USB Factory
class USBFactory:public HardwareFactory
{
public:
    HWProduct* getProduct()
    {
        return new USBProduct();
    }
    ~USBFactory(){}
};
// Concrete PCI Factory
class PCIFactory:public HardwareFactory
{
public:
    HWProduct* getProduct()
    {
        return new PCIProduct();
    }
    ~PCIFactory(){}
};

class Application
{
public:
    Application(HardwareFactory* factory) 
    { 
        HWProduct* product = factory->getProduct(); 
        product->readData();
        product->writeData();
        delete product;
        delete factory;
    }
};

HardwareFactory* getHWFActory(short int FactoryID)
{
    if(FactoryID == 1)
        return new USBFactory();
    else
        return new PCIFactory();
} 

int main()
{
    Application
    application(getHWFActory(2));
    return 0;
}