Item Service in AX 2012- This document does not support the AxEcoResProductIdentifier class or AxEcoResProductCategory class

In AX 2012's Item service as part of creating an Item/Product through AIF Service if you try to populate entities EcoResProductIdentifier, EcoResProductCategory you may receive these errors:

This document does not support the AxEcoResProductIdentifier class
or
This document does not support the AxEcoResProductCategory class

You may very well receive these errors after going through the AIF wizard and regenerating the Item Service (InventTable and EcoResProduct), the reason being wizard doesn't generate some code related to all the Tables involved in the AxdQuery.

To fix this, I had to add following code in class -> AxdEcoResProduct-> prepareForSave()

       case classNum(AXEcoResProductIdentifier):
            axecoResProductIdentifier   = _axdStack.top() as AxEcoResProductIdentifier;
            axEcoResProduct             = axecoResProductIdentifier.parentAxBC() as AxEcoResProduct;
            axecoResProductIdentifier.parmProduct(axEcoResProduct.parmRecId());
            return true;       
        
        case classNum(AxEcoResProductCategory):
            axEcoResProductCategory     = _axdStack.top() as AxEcoResProductCategory;
            axEcoResProduct             = axEcoResProductCategory.parentAxBC() as AxEcoResProduct;
            axEcoResProductCategory.parmProduct(axEcoResProduct.parmRecId());
            return true;       

Ofcourse I had declare the corresponding variables.
Happy Daxing.....