Language Detection Functions

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These functions determine which language is currently active, what the default language is, and which languages are configured on the site. They are defined in langforge.php and available globally once the plugin is active.

lf_get_current_language()

Returns the currently active language code.

/**
 * Get the current language code.
 *
 * Detection order:
 *   1. URL prefix / parameter / subdomain / domain mapping
 *   2. Site default language
 *
 * Note: when `lf_auto_detect_language` is enabled, the Accept-Language
 * header is consulted ONCE per browser at front-controller time. If a
 * non-default language is preferred, the request is redirected to the
 * `/{lang}/` URL before `template_redirect` runs — so by the time any
 * template code calls `lf_get_current_language()`, the language has
 * been "chosen" by the URL. The function itself never returns a
 * browser-detected language in place of a URL-derived one.
 *
 * @return string Language code (e.g., 'en', 'ru', 'de')
 */
$lang = lf_get_current_language();
// Returns: 'en'

Parameter	Type	Description
(none)	—	This function takes no parameters

Return Type	Description
`string`	Two-letter language code. Never returns empty; falls back to default language.

The current language is detected from the URL (directory prefix, query parameter, subdomain, or domain mapping), then falls back to the site default language. Cookie-based detection is intentionally avoided for clean default-language URLs. If browser auto-detection is enabled (lf_auto_detect_language), it is applied via a 302 redirect to /{lang}/ on the visitor’s first page load rather than by silently switching language at runtime — this keeps hreflang, canonical URLs, and crawler indexing clean. The redirect sets a long-lived lf_autodetect_done cookie so it runs at most once per browser.

Example 1: Language-conditional logic

// Load language-specific stylesheets
$lang = lf_get_current_language();

if ($lang === 'ar' || $lang === 'he') {
    // Load RTL stylesheet for Arabic and Hebrew
    wp_enqueue_style('theme-rtl', get_template_directory_uri() . '/css/rtl.css');
}

if ($lang === 'ru') {
    // Load Russian-specific typography adjustments
    wp_enqueue_style('theme-ru', get_template_directory_uri() . '/css/ru.css');
}

Example 2: Conditional body class

// functions.php - Add language as a body class
add_filter('body_class', function ($classes) {
    $classes[] = 'lang-' . lf_get_current_language();
    return $classes;
});
// Output: <body class="... lang-en">

Example 3: Language-specific widget area

// sidebar.php
$lang = lf_get_current_language();

if (is_active_sidebar('sidebar-' . $lang)) {
    dynamic_sidebar('sidebar-' . $lang);
} else {
    dynamic_sidebar('sidebar-default');
}

lf_get_default_language()

Returns the site’s default language code as configured in Lang Forge > Settings.

/**
 * Get the site's default language code.
 *
 * @return string Default language code (e.g., 'ru')
 */
$default = lf_get_default_language();
// Returns: 'ru'

Parameter	Type	Description
(none)	—	This function takes no parameters

Return Type	Description
`string`	The default language code configured in settings

Example 1: Check if viewing a non-default language

$current = lf_get_current_language();
$default = lf_get_default_language();

if ($current !== $default) {
    // Show a "View original" link
    $default_langs = lf_get_languages();
    $default_name = $default_langs[$default]['native_name'] ?? $default;
    echo '<a href="' . esc_url(home_url('/')) . '">';
    echo esc_html(sprintf('View in %s', $default_name));
    echo '</a>';
}

Example 2: Apply default language as the HTML lang attribute fallback

// functions.php
add_filter('language_attributes', function ($output) {
    $lang = lf_get_current_language();
    $languages = lf_get_languages();
    $locale = $languages[$lang]['locale'] ?? $lang;
    return 'lang="' . esc_attr(str_replace('_', '-', $locale)) . '"';
});

Example 3: Redirect to default language on 404

add_action('template_redirect', function () {
    if (is_404()) {
        $default = lf_get_default_language();
        $current = lf_get_current_language();
        if ($current !== $default) {
            wp_safe_redirect(home_url('/'));
            exit;
        }
    }
}, 99);

lf_get_languages()

Returns an associative array of all active languages configured in the site.

/**
 * Get all active languages.
 *
 * @return array Associative array keyed by language code.
 *               Each entry contains: name, native_name, flag, locale
 */
$languages = lf_get_languages();

Parameter	Type	Description
(none)	—	This function takes no parameters

Return Type	Description
`array`	Associative array keyed by language code

Return format:

[
    'ru' => [
        'name'        => 'Russian',
        'native_name' => 'Русский',
        'flag'        => 'ru',
        'locale'      => 'ru_RU',
    ],
    'en' => [
        'name'        => 'English',
        'native_name' => 'English',
        'flag'        => 'gb',
        'locale'      => 'en_US',
    ],
]

Example 1: Build a custom language list with flags

$languages = lf_get_languages();
$current   = lf_get_current_language();
$core      = LF_Core::instance();

echo '<ul class="custom-lang-list">';
foreach ($languages as $code => $lang) {
    $active_class = ($code === $current) ? ' class="active"' : '';
    $url = esc_url($core->get_language_url($code));
    $flag_url = plugins_url('langforge/assets/flags/' . $lang['flag'] . '.svg');

    echo '<li' . $active_class . '>';
    echo '<a href="' . $url . '">';
    echo '<img src="' . esc_url($flag_url) . '" alt="" width="20" height="14"> ';
    echo esc_html($lang['native_name']);
    echo '</a>';
    echo '</li>';
}
echo '</ul>';

Example 2: Generate JSON for a JavaScript language picker

// Enqueue language data for a frontend JS component
add_action('wp_enqueue_scripts', function () {
    $languages = lf_get_languages();
    $current = lf_get_current_language();
    $core = LF_Core::instance();

    $lang_data = [];
    foreach ($languages as $code => $lang) {
        $lang_data[] = [
            'code'       => $code,
            'name'       => $lang['name'],
            'nativeName' => $lang['native_name'],
            'flag'       => $lang['flag'],
            'url'        => $core->get_language_url($code),
            'isCurrent'  => ($code === $current),
        ];
    }

    wp_localize_script('theme-main', 'lfLanguages', $lang_data);
});

Example 3: Language count for conditional logic

$languages = lf_get_languages();

// Only show language switcher if more than one language is active
if (count($languages) > 1) {
    echo lf_language_switcher(['style' => 'dropdown']);
}

—

2. Language Detection Functions

lf_get_current_language()

lf_get_default_language()

lf_get_languages()