biztalk - Calling Restful Services Dynamically -

i have existing orchestration calls services below configuration.

system.diagnostics.eventlog.writeentry("abc", message_datasheets(file.receivedfilename)); varnewsearchdataloadurl = system.configuration.configurationmanager.appsettings["newsearchdataloadurl"]; varnewxmlmsg = new system.xml.xmldocument();  varnewxmlmsg.loadxml(@"<path>" + message_datasheets(file.receivedfilename) + @"</path>"); message_newunzip = varnewxmlmsg; message_newunzip(http.requesttimeout) = 3600; port_newjaxmicesearch_api(microsoft.xlangs.basetypes.address) = varnewsearchdataloadurl + "?path=" + message_datasheets(file.receivedfilename); port_newjaxmicesearch_api(microsoft.xlangs.basetypes.transporttype) = "http" 

here newsearchdataloadurl holds address of webservice needs called in config file.and path holds received file name.so called uri "http://new.abc.org/abcsearchwebapi/api/search/loaddatafeed?path=\share01\biztalk\data\out\20150723"

now have change restful services uses webhttp adapter. trying follow here

but dont understand btsvariablepropertymapping because dont have schema has value promoted. how can approach this. appreciated.

so goal call rest webservice using dynamic port, in order need
1 - specifiy type of operation

 <btshttpurlmapping>   <operation name=’myrestget’ method=’get’ url=’/xxxx/{empid}’ /> </btshttpurlmapping> 

2 - create , map variables :
"btsvariablepropertymapping" powerful biztalk technique enables define a custom variable in url , map context property using name , namespace must have property schema unless it's biztalk context property hence schema present in biztalk

3 - init dynamic port webservice url
in step assign webservice url , transport type in dynamic solicit response port

microsoft.xlangs.basetypes.adress = /xxxx/{empid} microsoft.xlangs.basetypes.transporttype = "wcf-webhttp" 

and go this