How can the context node point to an XPath object?

It is not clear to me, how to make the context node point to an XPath object, like Boolean for example.

XPath 1.0 only accept a single node as the "context node", and it does not support XML Schema types, thus, any node value is an XPath string object.

Section 8.2.6:
"When XPath 1.0 is used as Query Language [...] If the type is a simple type, the context node MUST point to the XPath object specified in section 8.2.2"

Section 8.2.2:
"WS-BPEL simple type variables MUST be manifested directly as either an XPath string, Boolean or float object."


For example, the ActiveBPEL implementation uses jaxen for XPath execution. The jaxen API allows you to pass a java.lang.Object as the context node. This must be a DOM node, Boolean, Number, or String. If query is running against a simple type variable then this variable has its value converted to the appropriate xpath type and passed in as the context.

Yes, I agree that the WS-BPEL specification is clear, and I do fully understand the intentions. But acording to the XPath 1.0 specification, the context node is a node, not an object.

Thus, the XPath 1.0 specification does not allow an object to be the context node, as I understand it.

Does WS-BPEL tweak the XPath specification, but setting up these requirements? It this deliberate? ...or is my understanding of the XPath 1.0 specification simply too square? Focus Areas: BPEL | DITA | ebXML | IDtrust | OpenDocument | SAML | UBL | UDDI
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