The way phonegap apps typically do this is via plugins.
You can find more info on how to write your plugin here Plugin Development Guide - Apache Cordova
Once you take that approach, you can let cordova.exec do the heavy lifting for you.
You can also dig into the way cordova works in the apache/cordova-ios repo.
also kindly clarify me...Is it possible that I can have part of the application in cordovan web view and its plugin and remaining parts in native sdk.