.. _auto_string_is_empty:

*CHECK IF STRING UNDEFINED*
===========================

Checks whether a given string is empty, null, or matches a user-defined set of null-equivalent values (e.g. "null", "none"). Use this worker in workflow branching logic to guard against undefined or missing string values before downstream processing.

When to use
-----------

Classification: **process**.

Tagged: ``"``, ``_``, ``a``, ``b``, ``c``, ``d``, ``e``, ``g``.

Inputs
------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - String
     - string
     - scalar
     - —
     - 
     - The scalar string value to evaluate; leave empty or unset to test for a missing/undefined input.
   * - Possible Null Values
     - null_values
     - scalar
     - null,none
     - 
     - Comma-separated list of values that should be treated as null/empty (e.g. 'null,none'); defaults to 'null,none' and is case-insensitive.

Outputs
-------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - string_is_empty_output_1
     - string_is_empty_output_1
     - scalar
     - Boolean-like scalar result (true/false) indicating whether the input string is empty or matches one of the defined null values.

Disciplines
-----------

- data.dataset.transform
- platform.workflow

Runnable example
----------------

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=string_is_empty <https://www.d3view.com/api/workflow/example?id=string_is_empty>`_

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>string_is_empty</code>. Schema hash: <code>8914e472662f</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>