Check whether a locale is configured

POM Translate does not expose a separate pom_translate_language_exists() helper. Check membership in the configured locale list:

$locale = 'es_ES';
$exists = function_exists( 'pom_translate_get_available_languages' )
    && in_array( $locale, pom_translate_get_available_languages(), true );

Use strict comparison and a full normalized WordPress locale. If an input may be a short code, resolve it with pom_translate_code_to_locale() before checking; an empty result is not configured.

Do not accept an arbitrary request locale merely because WordPress recognizes it globally. POM Translate routes, translations, and selectors are limited to languages configured for the current site.

For user input, sanitize the string first and independently validate permissions, nonces, and the requested operation. Locale existence is not an access-control check.