[ndnSIM] Conversion from ns3::Application to specific application type.

[Anil Jangam]

This the correct way to get the reference to the installed application
instance.

Ptr<ndn::NlsrApp> nlsrApp =
(*i)->GetApplication(0)->GetObject<ndn::NlsrApp> ();

Also thanks to this "ns3-users" post, where I get the answer from.
https://groups.google.com/forum/#!topic/ns-3-users/nvCaq98lRBY

/anil.


On Sat, Dec 19, 2015 at 6:12 PM, Anil Jangam <anilj.mailing at gmail.com>
wrote:

> Thanks Junxiao,
>
> I did not understand how Application object is installed using
> AddApplication() in the Install() method of AppHelper and yet it can be
> retrieved by node->GetObject<ConsumerCbr>(). This API is not symmetric but
> it working!
>
> ->GetObject<ConsumerCbr>(), I think is typically used when the object is
> added to the node by aggregate() function, isn't it?
>
> Since the install uses AddApplication() I think we can use
> GetApplication() to get reference to installed application. My type casting
> is failing at compile time.
>
> error: invalid conversion from ‘ns3::Application*’ to ‘ns3::ndn::NlsrApp*’
> [-fpermissive]
>
> The corresponding line is. So what kind of type casting required here?
>  Ptr<ndn::NlsrApp> nlsrApp = (Ptr<ndn::NlsrApp>) (*i)->GetApplication(0);
>
> AFA setting attributes is concerned, I do not know how it works. I want to
> set the config object into the application used inside the application's
> logic. To give an analogy, I am trying to set the configuration object
> inside the app::RealApp.
> I have exact same implementation as given here:
> http://ndnsim.net/2.1/guide-to-simulate-real-apps.html (Read from : How
> to simulate real applications...)
>
> /anil.
>
>
>
> On Sat, Dec 19, 2015 at 3:00 PM, Junxiao Shi <shijunxiao at email.arizona.edu
> > wrote:
>
>> Hi Anil
>>
>> To get Ptr<ConsumerCbr> from Ptr<Application>, you may use type-casting
>> or ->GetObject<ConsumerCbr>().
>>
>> The proper way to set a parameter onto an application object is through
>> ns-3 attributes.
>>
>> See ns-3 Manual <
>> https://www.nsnam.org/docs/release/3.24/manual/html/index.html> "Object
>> Model" and "Configuration and Attributes" section for more information.
>>
>> Yours, Junxiao
>> On Dec 19, 2015 3:45 PM, "Anil Jangam" <anilj.mailing at gmail.com> wrote:
>>
>>> Hi,
>>>
>>> In a scenario where an application instance is installed on the nodes,
>>> what is the way to retrieve that application instance from the node?
>>>
>>> In my requirement, I want to set some parameters into my application
>>> object, which is not possible at the time it is installed on the node.
>>> Perhaps they all do not use the parametrized constructor (I am talking
>>> about the classes in ns-3/src/ndnSIM/apps path).
>>>
>>> In an example below:
>>>  80   ndn::AppHelper consumerHelper("ns3::ndn::ConsumerCbr");
>>>  83   consumerHelper.Install(consumerNodes);
>>>
>>> I want to retrieve back the instance of "ns3::ndn::ConsumerCbr" from the
>>> consumerNodes object.
>>>
>>> I checked the API in bit details, the ndn-app-helper has this code:
>>> 119   Ptr<Application> app = m_factory.Create<Application>();
>>> 120   node->AddApplication(app);
>>>
>>> The node interface also provides an API GetApplication, but it returns
>>> Application instance:
>>> 160 Ptr<Application>
>>> 161 Node::GetApplication (uint32_t index) const
>>>
>>> How to convert it from ns3::Application to ns3::ndn::ConsumerCbr?
>>> Perhaps this is simple type casting operation, but just want to confirm it.
>>>
>>> Any other suggestion to achieve the same (i.e. updating the application
>>> instance installed on the node) is also fine with me.
>>>
>>> /anil.
>>>
>>>
>>>
>>> _______________________________________________
>>> ndnSIM mailing list
>>> ndnSIM at lists.cs.ucla.edu
>>> http://www.lists.cs.ucla.edu/mailman/listinfo/ndnsim
>>>
>>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.lists.cs.ucla.edu/pipermail/ndnsim/attachments/20151226/618e2a8a/attachment.html>