FME Form: 2024.1

Custom Transformer Parameters

When you open a custom transformer, a Transformer Parameters node appears in the FME Workbench Navigator. This node contains parameters that are common to all custom transformers.

Name of the custom transformer

If a custom transformer is exported, it can be password-protected. For more information, see Workspace Parameters.

Determines how the transformer is referenced in workspaces. May depend on whether the transformer is exported or not.

If Yes, the transformer is no longer available for use in newly-created workspaces. It remains usable only in existing workspaces.

Specifies the number of threads the custom transformer can process in parallel.

Level Number of Processes
No Parallelism 1
Minimal Cores / 2
Moderate Exact number of cores
Aggressive Cores * 1.5
Extreme Cores * 2

For more information, see Custom Transformers and Parallel Processing.

Specifies an attribute or parameter by which to group parallel processing threads. For example, if the attribute 'STATE' is specified, the transformer processes each state in parallel.

If When All Features Received, the FME engine can assume that data is inputted to the custom transformer in order for each Group By parameter value. This setting provides a performance and memory boost, because the engine does not need to wait for all features to arrive before beginning a process. Set this value to When Group Changes (Advanced) only if the structure of your dataset allows for data throughput in order by the Group By setting.

For information about Description parameters, see Workspace Parameters.

Enable  Blocked Looping

If Yes, the transformer can bypass its blocking behavior when used in a loop, and the following additional parameters apply:

  • Maximum number of iterations
  • Atttribute to hold iteration count

For more information, see Looping with a Blocking Transformer.

Incoming Attribute Preservation

Use this parameter to optimize performance by controlling how FME Workbench determines the output of attributes that enter the custom transformer. If you already know all incoming attributes either pass through or are dropped by the custom transformer, the All Attributes or Drop Attributes settings, respectively, allow FME Workbench to avoid the calculations that are otherwise necessary to achieve the same results.

  • Automatic: FME Workbench determines which incoming attributes are output by each port.
  • All Attributes: Instructs FME Workbench to pass through all incoming attributes to all output ports. Use this setting if you already know the custom transformer performs in this manner.
  • Drop Attributes: Instructs FME Workbench to eliminate all incoming attributes (that is, no incoming attributes are output). Use this setting if you already know the custom transformer performs in this manner, or you do not need FME Workbench to provide a final display of output attributes.

Python Compatibility

See Python Compatibility.