After creating transformation logic for a mapplet, you can create mapplet ports. Use an Input transformation to define mapplet input ports if the mapplet contains no source definitions. Use an Output transformation to create a group of output ports. Only connected ports in an Input or Output transformation become mapplet input or output ports in a mapping. Unconnected ports do not display when you use the mapplet in a mapping.
You can create a mapplet port in the following ways:
Manually create ports in the Input/Output transformation.
You can create port names in Input and Output transformations. You can also enter a description for each port name. The port has no defined datatype, precision, or scale until you connect it to a transformation in the mapplet.
Drag a port from another transformation.
You can create an input or output port by dragging a port from another transformation into the Input or Output transformation. The new port inherits the port name, description, datatype, and scale of the original port. You can edit the new port name and description in the transformation. If you change a port connection, the Designer updates the Input or Output transformation port to match the attributes of the new connection.
You can view the datatype, precision, and scale of available mapplet ports when you use the mapplet in a mapping.