BeforeExecute implements the IWebNode method of the same name. The remote interface object (TRio) calls this method after its OnBeforeExecute event, but before calling the Execute method to send a request to the server. BeforeExecute looks up the information needed to call the server from the invocation registry, based on either the URL that was supplied to the remote interfaced object or on the WSDLLocation, Service, and Port that were supplied to the remote interfaced object. If the method call requires an attachment, BeforeExecute looks up the MIME boundary for the attachment and adds headers to indicate the MIME boundary and content type of the attachment. 

IntfMD is the runtime type information (RTTI) of the invokable interface that includes the method to execute. 

MethMD is describes the method that is about to be executed. 

MethodIndex indicates which overload to use when methMD describes an overloaded method. 0 indicates the first overload, 1 indicates the second overload, and so on.  

AttachHandler is an interface to use for handling any attachments that are used as parameters of the method. If AttachHandler is nil (Delphi) or NULL (C++), the method call does not require passing any attachments. 

Execute 

OnBeforeExecute 

BeforeExecute 

URL 

WSDLLocation 

Service 

Port