Understanding nodes and mappings

The integration projects that you build using Studio are based on industry standards, including BPEL4WS (business process execution language for Web Services), WSDL (web services description language), and other XML based standards.

You do are not required to know the technical details of these standards to use the product. Nonetheless, as you work with Studio, you are exposed to the XML content of your inputs and outputs. Since orchestrations running on the Integration Appliance use, process, and deliver messages in an optimized XML format, all data and its definition is presented as a hierarchy of nodes, as in an XML document.

For example, columns in a database table are represented as nodes. As another example, Flat File Schemas are defined in Studio as a series of record, field, or group nodes in a tree structure that comprises a root node containing descendents (children, grandchildren, etc).

There are two basic distinctions between node types in Studio:
  • Structure nodes are nodes that convey information about structure only. An example of a structure node is a record definition (defined for a Flat File Schema). Structure nodes can contain other structure nodes, and nodes that contain data.
  • Data nodes are nodes that can contain data.

In a typical complete node representation, the top node is often referred to as the root node—root in the sense that it contains all other nodes. Subsequent nodes are descendent nodes comprised of both structure nodes and data nodes.

A key part of designing an orchestration is specifying the mapping between nodes, that is, defining how nodes and the data they contain should be used and transformed in the course of orchestration processing.

Several XML-specific characteristics can be associated with nodes; these characteristics are represented as an additional icon adjacent to a node in a tree. These properties include:
  • Recurring - denotes that a node can repeat (either a specified number of times or an unbounded number of times). Each time a recurring node repeats is an occurrence of the node.
  • Nillable - a boolean property that denotes whether the data node to which this property is associated can have an attribute set to “nil” by the application. The nillable mechanism is defined by the XML Schema recommendation as a way to identify non-required data elements that are empty vs. those that convey a null data value.
  • Optional - denotes whether an optional node exists or not.

Studio activities contain embedded maps that you must configure at design time, in the context of an orchestration, to define how actual parameters should map to variables, and how the variables should be processed in the orchestration.

The characteristics and node structure of the node tree in the right pane of the mapping editor determines whether a node from the left pane can be mapped to the right pane.




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Timestamp icon Last updated: Thursday, December 17, 2015


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