22. Language Detection Filters

Filters that control how Lang Forge detects and resolves the current language.

pre_get_posts — Language Filtering

Lang Forge filters the main query to show only posts in the current language. Priority 10 is used for general filtering, priority 5 for front page resolution.

// Add your own pre_get_posts AFTER Lang Forge (priority > 10)
add_action('pre_get_posts', function ($query) {
    if (!$query->is_main_query() || is_admin()) return;

    $lang = lf_get_current_language();

    // Example: exclude a category for English visitors
    if ($lang === 'en') {
        $query->set('category__not_in', [42]);
    }

    // Example: change posts per page for German
    if ($lang === 'de') {
        $query->set('posts_per_page', 5);
    }
}, 20);

locale — Locale Switching

Lang Forge filters the WordPress locale to match the current language. This affects date formatting, number formatting, and WordPress admin translations:

// The locale is automatically switched. For example, when viewing /en/:
echo get_locale(); // 'en_US'

// When viewing /de/:
echo get_locale(); // 'de_DE'

template_redirect — Language Cookie and Content Switching

At template_redirect priority 1, Lang Forge switches to the translated content version if available. At priority 2, 404 pages are redirected to the homepage in the current language.

// Run code after Lang Forge has set up the language
add_action('template_redirect', function () {
    $lang = lf_get_current_language();
    // Your logic here - language is guaranteed to be resolved
}, 10);

option_page_on_front — Translated Front Page

Lang Forge maps the page_on_front option to the translated page ID for the current language. This ensures is_front_page(), breadcrumbs, and menu active states all work correctly.

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