Re: Abstract Factory Design Patterns Advice

From:
DeMarcus <use_my_alias_here@hotmail.com>
Newsgroups:
comp.lang.c++.moderated
Date:
Tue, 23 Jun 2009 19:36:52 CST
Message-ID:
<4a4145f9$0$48239$14726298@news.sunsite.dk>

OK, I get your point. Why you say container is good for
polymorphism ?
In what situation container is more suitable than polymorphism ?


I mean that polymorphism and containers work very well together. You can
load a lot of different objects in for instance a std::vector and then
loop over the vector and run a common virtual method. Say you want to
initialize all your factories, then you don't have to write:

adminFactory.init();
hrFactory.init();
staffFactory.init();

but instead you just loop:

for( std::map<std::string, ObjectFactory*>::iterator i =
    factoryMap.begin(); i != factoryMap.end(); ++i )
{
    (*i).second->init();
}

I have a question here. After i create the appropriate user, how to
forward call to the user using this approach ?


It depends if the call is a common call receivable by all the users then
use polymorphism again:

class User // Interface
{
public:
    virtual ~User() {}
    virtual void receiveCall( const std::string& call ) = 0;
};

class AdminUser : public User
{
public:
    virtual void receiveCall( const std::string& call ) { /* ... */ }
};

// Following may not be an optimal design, but rather a hint to your work.

User* user = factoryMap[userString]->createUser();
user->receiveCall( callString );

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