wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Lib;

use MediaWiki\Html\Html;
use Wikibase\DataModel\Term\TermFallback;

/**
 * Generates HTML (usually a 'sup' element) to make the actual and source languages of terms
 * (typically labels and descriptions) that are the result of a language fallback chain and/or
 * transliteration visible to the user.
 *
 * Implementation note: languageFallbackIndicator.js contains similar functionality in JS.
 *
 * @license GPL-2.0-or-later
 * @author Adrian Heine <adrian.heine@wikimedia.de>
 * @author Thiemo Kreuz
 */
class LanguageFallbackIndicator {

    /**
     * @var LanguageNameLookup
     */
    private $languageNameLookup;

    public function __construct( LanguageNameLookup $languageNameLookup ) {
        $this->languageNameLookup = $languageNameLookup;
    }

    public function getHtml( TermFallback $term ) {
        $requestedLanguage = $term->getLanguageCode();
        $actualLanguage = $term->getActualLanguageCode();
        $sourceLanguage = $term->getSourceLanguageCode();

        $isFallback = $actualLanguage !== $requestedLanguage;
        $isTransliteration = $sourceLanguage !== null && $sourceLanguage !== $actualLanguage;

        if ( !$isFallback && !$isTransliteration ) {
            return '';
        }

        if ( $isFallback && !$isTransliteration ) {
            if (
                $this->getBaseLanguage( $actualLanguage ) === $this->getBaseLanguage( $requestedLanguage )
                    || $actualLanguage === 'mul'
            ) {
                return '';
            }
        }

        $text = $this->languageNameLookup->getNameForTerms( $actualLanguage );

        if ( $isTransliteration ) {
            $text = wfMessage(
                'wikibase-language-fallback-transliteration-hint',
                $this->languageNameLookup->getNameForTerms( $sourceLanguage ),
                $text
            )->text();
        }

        $classes = 'wb-language-fallback-indicator';
        if ( $isTransliteration ) {
            $classes .= ' wb-language-fallback-transliteration';
        }
        $attributes = [ 'class' => $classes ];

        $html = Html::element( 'sup', $attributes, $text );
        return "\u{00A0}" . $html;
    }

    /**
     * @param string $languageCode
     *
     * @return string
     */
    private function getBaseLanguage( $languageCode ) {
        return preg_replace( '/-.*/', '', $languageCode );
    }

}