10.4.3 Usage of Data in XPath Expressions

BPMN extensibility mechanism enables the usage of various languages for Expressions and queries. This sub clause describes how XPath is used in BPMN. It introduces a mechanism to access BPMN Data Objects, BPMN Properties, and various instance attributes from XPath Expressions. The accessibility by the Expression language is defined based on the entities accessibility by the Activity that contains the Expression. All elements accessible from the enclosing element of an XPath Expression MUST be made available to the XPath processor.

BPMN Data Objects and BPMN Properties are defined using ItemDefinition. The XPath binding assumes that the ItemDefinition is either an XSD complex type or an XSD element. If XSD element is used, it MUST be manifested as a node-set XPath variable with a single member node. If XSD complex type is used, it MUST be manifested as a nodeset XPath variable with one member node containing the anonymous document element that contains the actual value of the BPMN Data Object or Property.