hard to use AMI,help me,please

[nyingchi]

The blow is a simple example only to explain what problem i encountered.

Chat.ice
-----------------------------------------
#ifndef CHAT_ICE
#define CHAT_ICE

module Demo
{
interface Chat
{
["ami"]bool login(string name);
};

};

#endif // define CHAT_ICE
-----------------------------------------
class ChatI : public Demo::Chat
{
//............
};

class A defined in C++
{
public
void login();
//............
private:
std::string _name;
bool _IsLogin;
Demo::ChatPrx _chati; // * a member of class A
}

// implementation of functon login() using login_async
void A::login()
{

AMI_Chat_loginPtr amiptr = new AMI_Chat_loginI;
_chati->login_async(amiptr,"kin");
}

-----------------------------------------
the question is :
if i use synchronous programming model. it is very easy to get the value _IsLogin:
_IsLogin = _chati->login("kin");

but now, how to change the data member A::_IsLogin when the AMI invloved????

class AMI_Chat_loginI : public Demo::AMI_Chat_login
{
void ice_response(bool res)
{
//
//how to change the data member
// A::_IsLogin when the AMI invloved????
// seems it is impossible to modefiy here
//
}

void ice_exception(const ::Ice::Exception&){}
};

[benoit]

Hi,

You need to add a setIsLogin method to your class A to modify the _IsLogin attribute and call it from the AMI callback, for example:

class AMI_Chat_loginI : public Demo::AMI_Chat_login
{

AMI_Chat_loginI(A& a) : _a(a) 
{ 
}

void ice_response(bool res)
{
    _a.setIsLogin(res)
}

void ice_exception(const ::Ice::Exception&)
{
}

private:

// Using a reference might not be appropriate here 
// if A might have been destroyed by the time the 
// response is sent (you should reference count the A
// class if that's the case).
//
A& _a; 

};

Note also that you'll probably have to add some synchronization to the setIsLogin method since the _IsLogin attribute will be accessed from different threads.

Cheers,
Benoit.

[nyingchi]

i got it .
thanks for your prompt reply which gives me lots of hints.
because my english is poor ,
i dont know how to deliver my deep thanks for your kindly help.
thanks.

[nyingchi]

now my solution is below. i use the following code to show my solution,not in details.

will you tell me the advantage and disadvantafe of this solution? thanks.

Chat.ice

as before
-----------------------------------------
AA.ice

module Demo
{
interface AA
{
bool loginResult(bool ret);
};
};
-----------------------------------------

class AAI : public Demo::AA
{
public:
bool loginResult(bool ret, Ice::Current &);

inline void IsLogin()
{
return _IsLogin;
}

// and so on .........

private:
bool _IsLogin;
}

typedef IceUtil::Handle<AAI> AAPtr;

-------------------------------------------
class A
{
public:

A(const Ice::ObjectAdapter &adapter,const AAPtr aa):
_adapter(adapter),_aai(aa);
{
Ice::Identity id;
id.name = // some unique name;
_adapter->add(_aai,id)
};

void login();

void IsLogin()
{
return _aai.IsLogin();
};

private:

AAPtr _aai // * a member of class A
std::string _name;
Demo::ChatPrx _chati; // * a member of class A
Ice::ObjectAdapter _adapter;
std::string _name;

}
// implementation of functon login() using login_async
void A::login()
{
Ice::Identity id;

id.name = // some unique name;

AMI_Chat_loginPtr amiptr = new AMI_Chat_loginI(_adapter->createProxy(id));

_chati->login_async(amiptr,"kin");

}

void A::loginResult(bool ret, const ::Ice::Current&)
{
_IsLogin= ret;
// more codes here
// the new value _IsLogin can be used anywhere in class A
}

-----------------------------------------
class AMI_Chat_loginI : public Demo::AMI_Chat_login
{
AMI_Chat_loginI(const Ice::ObjectPrx& proxy):_proxy(proxy)
{};

void ice_response(bool res)
{
APrx proxy = APrx::uncheckedCast(_proxy);
proxy ->loginResult(res);
}

void ice_exception(const ::Ice::Exception&){}

private:
Ice::ObjectPrx _proxy;
}

[benoit]

Hi,

Why do you define another Slice interface, AA, just to pass the result of the login operation? It would be much simpler to just pass the reference of your `A' class as I've mentioned above.

Cheers,
Benoit.

[nyingchi]

In my application, it is necessary to define another slice because it has more responsibilities.

the reference idea is more simple. and now i use it .