[ndnSIM] NFD modification - Linker error

[Ιωάννα Αγγελική Καπετανίδου]

Hello all,

I am trying to modify NFD forwarder.cpp in order for it to be able to  
get a value from an application called NewConsumer. In the  
NewConsumer.hpp file I have two public functions: void  
setRating(uint32_t pr); and double getRating() const {return rating;}.  
setRating is defined in the NewConsumer.cpp file. In NewConsumer.hpp,  
I also have a public Constructor and a virtual Destructor,which are  
defined in the NewConsumer.cpp file,too.

My program is located in ndnSIM/examples/[myfoldername] (I have  
configured waf so that examples are enabled). When I create a  
NewConsumer object in another .cpp file in myfolder it works fine.  
However, my purpose is to incorporate setRating and getRating in  
forwarder.cpp, as I want to control data caching and forwarding  
operations.
I tried including NewConsumer.hpp and adding in  
Forwarder::onIncomingData the following code lines:

   ns3::Ptr<ns3::NewConsumer> newc = ns3::CreateObject<ns3::NewConsumer>();

   newc->setRating(stoi(dt.toUri()));
   std::cout << newc->getRating() << '\n';


  When I do this I get a linker error:

./libns3-dev-ndnSIM-debug.so: undefined reference to  
`ns3::NewConsumer::NewConsumer()'
./libns3-dev-ndnSIM-debug.so: undefined reference to  
`ns3::NewConsumer::setRating(unsigned int)'
./libns3-dev-ndnSIM-debug.so: undefined reference to  
`ns3::NewConsumer::GetTypeId()'
collect2: error: ld returned 1 exit status


Is there something else I have to do? Maybe include anything or  
modifications at some wscript file?
Looking forward to hearing your advice.

Thank you in advance,
Ioanna