Optymalizacja struktury nagłówków WordPress dla lepszego SEO

Kod

<?php

// Hook into 'wp_head' to add custom heading structure optimization
add_action('wp_head', 'wp_dudecom_optimize_heading_structure');

/**
 * Optimize the structure of headings H1, H2, H3 for SEO in WordPress.
 *
 * This function ensures that the heading tags are used correctly and optimally
 * for SEO purposes. It checks the current page type and adjusts the heading
 * structure accordingly.
 */
function wp_dudecom_optimize_heading_structure() {
    if (is_single() || is_page()) {
        // Ensure only one H1 tag is used per page
        add_filter('the_content', 'wp_dudecom_single_h1_tag');
    }
}

/**
 * Ensure only one H1 tag is used per page and optimize heading tags.
 *
 * @param string $content The content of the post or page.
 * @return string Modified content with optimized heading tags.
 */
function wp_dudecom_single_h1_tag($content) {
    // Use DOMDocument to manipulate HTML content
    libxml_use_internal_errors(true);
    $dom = new DOMDocument();
    $dom->loadHTML('<?xml encoding="utf-8" ?>' . $content);

    // Get all heading tags
    $headings = $dom->getElementsByTagName('*');
    $h1_count = 0;

    foreach ($headings as $heading) {
        if (in_array($heading->nodeName, ['h1', 'h2', 'h3'])) {
            // Count H1 tags
            if ($heading->nodeName === 'h1') {
                $h1_count++;
                if ($h1_count > 1) {
                    // Convert additional H1 tags to H2
                    $dom->createElement('h2', $heading->nodeValue);
                    $heading->parentNode->replaceChild($dom->createElement('h2', $heading->nodeValue), $heading);
                }
            }
        }
    }

    // Save the modified HTML
    $content = $dom->saveHTML();
    libxml_clear_errors();

    return $content;
}

?>