【コピペで完了】Rinkerを貼りすぎて重くなったページを「爆速」に変える裏技

/*
Rinker遅延読み込み
(ユーザー操作で開始 + 最大同時読込数 + 待機時間)
*/

//--------------------------------------
// 0. 環境設定（変数調整）
//--------------------------------------
define('RINKER_MAX_CONCURRENT', 20); //同時読み込み数
define('RINKER_INTERVAL_MS', 3000); //読み込み間隔[ms]
define('RINKER_EVENTS', ['scroll', 'mousedown', 'touchstart', 'keydown']); //読み込み開始の操作フラグ
define('RINKER_AUTO_START_MS', 5000); //無操作時の読み込み待機時間[ms]

//--------------------------------------
// 1. ショートコードをプレースホルダーに置き換え
//--------------------------------------
add_action('wp_loaded', function () {
    if (shortcode_exists('itemlink')) {
        remove_shortcode('itemlink');
        add_shortcode('itemlink', 'my_rinker_lazy_placeholder');
    }
}, 100);

function my_rinker_lazy_placeholder($atts)
{
    if (empty($atts['post_id'])) {
        return '';
    }

    $json_atts = esc_attr(json_encode($atts));

    return sprintf(
        '<div class="rinker-placeholder" data-atts="%s">読み込み中...</div>',
        $json_atts
    );
}

//--------------------------------------
// 2. Ajax リクエスト処理
//--------------------------------------
add_action('wp_ajax_rinker_load_action', 'my_rinker_ajax_handler');
add_action('wp_ajax_nopriv_rinker_load_action', 'my_rinker_ajax_handler');

function my_rinker_ajax_handler()
{
    $atts = json_decode(stripslashes($_POST['atts'] ?? ''), true);

    if (!empty($atts) && class_exists('Yyi_Rinker_Plugin')) {
        echo Yyi_Rinker_Plugin::get_object()->shotcode($atts);
    }

    wp_die();
}

//--------------------------------------
// 3. JavaScript：ユーザー操作で遅延読み込み開始
//--------------------------------------
add_action('wp_footer', function () {
?>
    <style>
        .rinker-placeholder {
            min-height: 150px;
            margin: 20px 0;
            display: flex;
            align-items: center;
            justify-content: center;
            background: #f9f9f9;
            border: 1px solid #eee;
            border-radius: 4px;
            color: #999;
            font-size: 14px;
        }
    </style>

    <script>
        (function () {
            const MAX_CONCURRENT = <?php echo RINKER_MAX_CONCURRENT; ?>;
            const INTERVAL_MS = <?php echo RINKER_INTERVAL_MS; ?>;
			const EVENTS = <?php echo json_encode(RINKER_EVENTS); ?>;
            const AUTO_START_MS = <?php echo RINKER_AUTO_START_MS; ?>;

            const queue = [];
            let activeCount = 0;
            let started = false;

            async function processQueue() {
                if (queue.length === 0 || activeCount >= MAX_CONCURRENT) return;

                activeCount++;
                const el = queue.shift();

                const body = new URLSearchParams({
                    action: 'rinker_load_action',
                    atts: el.dataset.atts
                });

                try {
                    const res = await fetch('<?php echo admin_url("admin-ajax.php"); ?>', {
                        method: 'POST',
                        headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
                        body: body.toString()
                    });

                    if (res.ok) {
                        const html = (await res.text()).replace(/0$/, '').trim();
                        if (html) el.outerHTML = html;
                    }
                } catch (e) {
                    console.error('Rinker Load Error:', e);
                } finally {
                    activeCount--;
                    setTimeout(processQueue, INTERVAL_MS);
                }
            }

            function startLoading(event) {
                if (started) return;
                if (event && event.type === 'scroll' && window.scrollY < 50) return;

                started = true;
                cleanup();

                const placeholders = document.querySelectorAll('.rinker-placeholder');
                placeholders.forEach(el => queue.push(el));

                for (let i = 0; i < MAX_CONCURRENT; i++) {
                    processQueue();
                }
            }

            function cleanup() {
                if (Array.isArray(EVENTS)) {
                    EVENTS.forEach(ev => window.removeEventListener(ev, startLoading));
                }
            }

            setTimeout(() => {
                if (Array.isArray(EVENTS)) {
                    EVENTS.forEach(ev =>
                        window.addEventListener(ev, startLoading, { passive: true })
                    );
                }
            }, 1000);

            setTimeout(() => {
                startLoading(); 
            }, AUTO_START_MS);
        })();
    </script>
<?php
}, 100);