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Updating deprecated Unicode::strtolower() calls in Drupal 8


This covers only the most common use cases.





Note that in this case, we are removing a helper service now that we can rely on a standard PHP function.

More examples

We have a set of examples as part of the Drupal Rector rector_examples module. See

Automating updates with Drupal Rector

Drupal Rector is an open source tool built using Rector which can help automate this deprecation as well as other common deprecations.

For more information, see

What is covered by the rector

Drupal Rector currently replaces static calls to \Drupal\Component\Utility\Unicode::strtolower() as shown above. This also works if the Unicode class is defined with a use statement.

Deprecation background

Drupal provided a way to provide unicode support for processing strings for versions of PHP that did not have this functionality. Symfony now includes a polyfill to handle these unicode functions when they are not provided by your PHP version.


The Drupal change record for this deprecation is available at

Credits and thank yous

Thank you to Dan Montgomery for leading Drupal Rector development to support this deprecation.

Thank you to for sponsoring this development.

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