Referring to File Columns in Stream Attribute Expressions

When using the File Columns in an output Stream of the File Collector, use the format:
<pipe name>.<attribute name>
You do not need to include the name of the target Record Node, or any child Records Nodes between the target and the Attribute Node. Using the example grammar and File Columns definition from section 4, if the File Collector was linked to an output Stream with a pipe named in, you could use the first name from a customer record with the expression
in.firstName
If you defined a Stream Attribute FirstName, and wanted it to be populated for both customers and agents, you could use the expression
ifNull(in.firstName, in.givenName)
Note that if you drag and drop File Columns from the File Collector into an output Stream (to create Stream Attributes), the Attribute Expressions will be correctly configured automatically.