.. _maskfield:

.. meta::
   :description: This document provides usage information for the Apache Kafka SMT org.apache.kafka.connect.transforms.MaskField.

=========
MaskField
=========

The following provides usage information for the |ak-tm| SMT ``org.apache.kafka.connect.transforms.MaskField``.

Description
-----------
Mask specified fields with a valid null value for the field type (i.e. 0, false, empty string, and so on).

Use the concrete transformation type designed for the record key (``org.apache.kafka.connect.transforms.MaskField$Key``) or value (``org.apache.kafka.connect.transforms.MaskField$Value``).

Example
-------

This configuration snippet shows how to use ``MaskField`` to mask the value of a
field.

.. sourcecode:: properties

   "transforms": "MaskField",
   "transforms.MaskField.type": "org.apache.kafka.connect.transforms.MaskField$Value",
   "transforms.MaskField.fields": "string_field"
   
This masks ``string_field``, transforming the original message as seen
here:

``{"integer_field":22, "string_field":"foo"}``

into the result here:

``{"integer_field":22, "string_field":""}``

Properties
----------

.. list-table::
   :header-rows: 1
   :widths: 15 30 10 10 10 10

   *  - Name
      - Description
      - Type
      - Default
      - Valid Values
      - Importance
   *  - ``fields``
      - Names of fields to mask.
      - list
      -
      - non-empty list
      - high