A custom transformer is a sequence of standard transformers condensed into a single transformer. Any existing sequence of transformers can be turned into a custom transformer.
Among other functions, custom transformers help to:
These are excellent methods for Best Practice.
The example below shows how a custom transformer can replace multiple transformers. Three transformers have been placed on the main canvas: one to create polygons, one to turn them into donuts, and one to measure the created features.
A custom transformer combines the three transformers into one:
The original transformers are moved to a separate tab on the workspace canvas. The input and output ports on the custom transformer are represented by the blue and green arrows.
Custom transformers execute the same data flow as the original transformers, and can be edited just like any other transformer.
You can use Custom Transformers in two ways:
Custom transformers can be used:
You can also export a Custom Transformer to share with other users. After they are exported, custom transformers can be:
The easiest way to create a custom transformer is by opening an existing workspace and selecting existing transformers:
By default, custom transformers are stored in My Documents\FME\Transformers.