Using Custom Transformers
Once a custom transformer has been created, it is connected into the workspace and - apart from a different color - looks just like a normal FME transformer would.
However, the resemblance to a normal transformer is not just in appearance. In the same way that multiple instances of a transformer can be used in a workspace, a custom transformer can be used any number of times too. This makes Custom Transformers not just a way to tidy a workspace, but also as a way of re-using content.
To place extra copies of a custom transformer - again like a regular transformer - you use the Transformer Gallery (look under a section labelled “Embedded Transformers):
...or you can use Quick Add:
As with FME transformers, each newly placed instance of a custom transformer will be renamed (or numbered) as necessary, in order to avoid a clash of names.
|The transformer name, category, and description all appear in the Quick Add tool - as well as appearing in the help window - so it is definitely worthwhile setting these parameters.|
Editing a Re-used Custom Transformer
Multiple instances of a custom transformer all use the same core definition; i.e. there may be multiple copies on the Main tab, but only a single tab for the custom transformer definition.
A key benefit of this approach is that every instance can be updated or edited simply by editing the custom transformer definition.
For example, if a parameter is changed for the Aggregator inside this custom transformer:
...then the parameter automatically changes for ALL instances of the transformer that have been placed.
This makes the editing of a sequence of transformers much easier, because the edit only needs to be made once, no matter how many times that sequence has been used.