Pass Qml object in signal

[MajidKamali]

Hi.
I created a c++ QObject based class and I use that in qml just fine.
I want to use object of that type in signal parameter.
I've done the following:

// Sender.qml
signal sigName(var obj) // signal definition
...
CppBasedClass { id: cls } // create object of that type
...
function func() {
   cls.property1 = ... // fill object
...
   sigName(cls) // emit signal
}

// Receiver.qml
CppBasedClass { id: recv }

Connections {
...
   onSigName: {
      recv = obj
      console.log(obj.property1) // works, prints property1 value
      console.log(recv.property1) // <-- does not work, prints nothing
   }
}

CppBasedClass have many properties and I need autocomplete feature. obj does not have any autocomplete, but recv does.
How can I achive this?

[MajidKamali]

Temporarily solved the prblem with this function:

// equivalent to: obj1 = obj2
    function assign(obj1, obj2) {
        for(var prop in obj2)
            if(obj2.hasOwnProperty(prop) && typeof obj2[prop] !== 'function')
                obj1[prop] = obj2[prop]
    }

because obj1 is of type obj2, there is no problem with this approach.

BUT main question remains unanswered. Why assignment does not work?