User Guide

106 Cross-Product Extensions

RPC server XML replies

After the RPC server processes an XML request, it packages the result as an XML fragment

and sends it back to the client. If an error occurred during processing, the server returns an

error code in the result XML. Otherwise, the reply node contains a single data node with the

result of the operation. If the request doesn’t require a return value, the reply node contains

either a single void data node or no children nodes.

For example, here is a successful reply:

Here is a successful reply with a server object:

Error codes

If the server encounters an error when processing a request, the reply node (with the node

name

return) contains at most one error attribute, as in this example:

The error attribute can contain one of the values listed in the following table.

NOTE

When the server returns a server object, it automatically retains the object on the client's

behalf. That is, the object returned to the client is not destroyed until the client releases it

with a release request, or until the client disconnects from the server. Therefore, the

client should release a server object as soon as the client has finished sending requests

related to that object (when the client is done “using” the object).

Error

code

Description

0 No error occurred, and the request completed successfully. The client should

never receive an error attribute with this value. If no error occurred, then no error

attribute will be present.

1 An unknown, generic error occurred. The RPC server could not make enough

sense of the request to give a specific error. Check the name of the XML nodes

and attributes.

2 No such object, invalid object ID. The object specified by the client does not

exist or the object ID is invalid.

3 No such method. The method that the client requested does not exist on the

specified object.

4 No such property. The property that the client requested does not exist on the

specified object.