Working with the Expression Node

Overview of the Expression Node

You can add an Expression node to a Flow tab in an orchestration job to embed DataFlux Expression Engine Language expressions. These expressions enable you to write complex job control flow logic. You can also use an expression to define slots that can change the flow of a job.

Inputs and Outputs to the Expression Node

The Expression node enables you to create a DataFlux Expression Engine Language expression in the context of an orchestration job. The expression takes data from a source such as a table or a node that precedes it a job as its inputs. Then, it processes these inputs in some way and sends the processed results out as outputs that are used later in the job.

Using the Expression Node

You can create an orchestration job that uses Expression nodes in the Flow tab to embed Expression Engine Language expressions in the context of the job. For example, a job that is intended to demonstrate the interactions of Event Listener nodes with other types of nodes includes Expression nodes. Each Expression node embeds unique output from the Event Listener node that precedes it in the job flow into an expression that is used in the job.
This sample orchestration job is shown in the following display:
Event Node Job with Specific Events
Event Node Job with Specific Events
The Outputs tab for the Event Listener 1 node is shown in the following display:
Event Listener 1 Output
Event Listener 1 Output
For more information about Event Listener nodes, see Working with the Event Listener Node.
The following display shows the expression entered in the Expression 1 node.
Expression 1
Expression 1