Pre-reqs: This document requires the readers to develop application id, query id, powl type, powl typerr and other mandatory settings before practicing this demo on powl vendor list.
I thought of exlporing powl in greator detail. I reviewed flight model webdynpro demo which is shipped with sap. I developed by feeder class using CL_MM_POWL_VENDOR_LIST. This powl displays vendor information. The first step was easy in setting up my powerlist by using IF_POWL_INTERFACE and developing the required view along with plugs.The next step is to develop another web dynpro component for displaying detail. When ever the user clicked on any row on powl list, this row would be displayed in the detail view. After implementing the interface POWL_DETAIL_COMP_IF in the detail view. The next step is to develop context for the detail component controller. For this task, if looked at into the get_objects of the feeder, and review the sql query 
Here, two views v_lfa1m1 and lfa1b1 are source of the the context development for the detail component for the master powl component. I developed a database table as shown below and developed context for the component controller and the view.
and the view in the detail component was developed as shown below.
The next step is to write code for the update_Detail_data for detail view. As shown next
Everything was going in the right direction untill i saw the following error
I realized that the imorting parameter I_powl_line_data, when assigned to the field symbol of the context node returns type conflict error. I analyse the dump which was created and found out the exact type of the type of i_powl_line_data,
here as the description said, I_powl_line_data belong s to my feeder class, that is z_mm_powl_vendor_list and its type is TY_LS"_VENDOR.
TY_LS_VENDOR declared privately in the class , i simply declared this type in update_detail_method of the detail component as shown below
after testing this code, the result comes perfect and the detail component works as shown below.
