Which method involves using an AttributeExposer before the custom transformer input and output port(s) to expose attributes?

• A. Double-click on the Transformer Input or Transformer Output port and check/uncheck the attributes
• B. Navigator > Transformer Parameters > Group By
• C. Tools > FME Options
• D. Use an AttributeExposer before the custom transformer input and output port(s)

Answer: (D)

Exposing attributes across a custom transformer boundary is done by placing an AttributeExposer just before the transformer’s input and output ports. This transformer explicitly lifts attributes so they become part of the external feature type, making them visible to downstream transformers. It’s the direct way to publish attributes that were created or hidden inside the custom transformer, so they can be used later in the workflow.

The other options don’t achieve this. Simply clicking a port to check or uncheck attributes only controls which existing attributes pass through a port from input to output, not attributes created inside the transformer. Paths like navigating to transformer parameters, adjusting groups, or changing global FME options don’t address exposing internal attributes at the transformer boundary.