Developing the PowerBuilder extension – PB Docs 2019

A PowerBuilder marshaler extension usually provides a native class
that acts as a creator. This class defines a function that creates an
instance of the foreign component that is specified in the parameters
passed into the function (1). If it succeeds in creating an instance of
the foreign component (2), it creates a proxy for it using the PBVM (3,
4), creates a marshaler object (5), and associates the marshaler with the
proxy (6).

Figure: Creating a foreign component, proxy, and marshaler

When a function of the proxy object is called in PowerScript, the
PBVM calls the InvokeRemoteMethod function on the marshaler object through
the proxy (1, 2). The marshaler object translates PowerBuilder function
calls into requests that the foreign component understands, sends the
requests (3), waits for a response, and send the results back to
PowerBuilder (4).

Figure: Invoking a remote method

To develop the extension, you need to:

Step 1: Describe the
extension

Step 2: Implement the
creator class

Step 3: Implement the
marshaler class