First, the publisher creates an instance of the XML Template by populating the template with dataslot values. It identifies the XML elements or locations to be populated with data in the XML Template, by the message properties specified for this workstep. These message properties contain the XPath location of the XML element as defined in the message metadata file. The message properties specified in the workstep are mapped to dataslots or constants, so that the XPath for the message property is replaced by the corresponding dataslot. The XML instance thus created forms the payload of the JMS message. If an XPath element is not mapped and a default value is defined for the element in the template, then this default value is used.