wiki.techinc.nl/includes/htmlform/fields/HTMLSelectLanguageField.php

<?php

use MediaWiki\MediaWikiServices;

/**
 * Language select field.
 *
 * @stable to extend
 */
class HTMLSelectLanguageField extends HTMLSelectField {

	/*
	 * @stable to call
	 */
	public function __construct( $params ) {
		parent::__construct( $params );

		if ( $this->mParent instanceof HTMLForm ) {
			$config = $this->mParent->getConfig();
			$languageCode = $config->get( 'LanguageCode' );
		} else {
			global $wgLanguageCode;
			$languageCode = $wgLanguageCode;
		}

		$languages = MediaWikiServices::getInstance()
			->getLanguageNameUtils()
			->getLanguageNames( null, 'mw' );

		// Make sure the site language is in the list;
		// a custom language code might not have a defined name…
		if ( !array_key_exists( $languageCode, $languages ) ) {
			$languages[$languageCode] = $languageCode;
		}

		ksort( $languages );

		foreach ( $languages as $code => $name ) {
			$this->mParams['options'][$code . ' - ' . $name] = $code;
		}

		if ( !array_key_exists( 'default', $params ) ) {
			$this->mParams['default'] = $languageCode;
		}
	}
}