Mapplet Input and Output
To use a mapplet in a mapping, you must configure it for input and output.
A mapplet has the following input and output components:
- •Mapplet input. You can pass data into a mapplet from data sources or Input transformations or both. If you validate the mapplet as a rule, you must pass data into the mapplet through an Input transformation. When you use an Input transformation, you connect it to a source or upstream transformation in the mapping.
- •Mapplet output. You can pass data out of a mapplet from data sources or Output transformations or both. If you validate the mapplet as a rule, you must pass data from the mapplet through an Output transformation. When you use an Output transformation, you connect it to a target or downstream transformation in the mapping.
- •Mapplet ports. You can see mapplet ports in the mapping editor. Mapplet input ports and output ports originate from Input transformations and Output transformations. They do not originate from data sources.
Mapplet Input
Mapplet input can originate from a data source or from an Input transformation.
You can create multiple pipelines in a mapplet. Use multiple data sources or Input transformations. You can also use a combination of data sources and Input transformations.
Use one or more data sources to provide source data in the mapplet. When you use the mapplet in a mapping, it is the first object in the mapping pipeline and contains no input ports.
Use an Input transformation to receive input from the mapping. The Input transformation provides input ports so you can pass data through the mapplet. Each port in the Input transformation connected to another transformation in the mapplet becomes a mapplet input port.
When you use an Input transformation to provide the input for a mapplet, you can set default values in the output ports of the Input transformation. The default values in the Input transformation output ports become default values for the mapplet input ports. If NULL data is passed from the mapping to the Input transformation, the Data Integration Service replaces the NULL value with the default value. The mapplet input uses the default value.
You can connect an Input transformation to multiple transformations in a mapplet. You can also connect one port in an Input transformation to multiple transformations in the mapplet.
Input transformations can receive data from a single active source. Unconnected ports do not appear in the mapping editor.
Mapplet Output
Use a data source as output when you want to create a target mapplet. Use an Output transformation in a mapplet to pass data through the mapplet into a mapping.
Use one or more data sources to provide target data in the mapplet. When you use the mapplet in a mapping, it is the last object in the mapping pipeline and contains no output ports.
Use an Output transformation to pass output to a downstream transformation or target in a mapping. Each connected port in an Output transformation appears as a mapplet output port in a mapping. Each Output transformation in a mapplet appears as an output group. An output group can pass data to multiple pipelines in a mapping.