// child.js
if (window.parent !== window) {
  const sendHeight = () => {
    window.parent.postMessage({
      type: 'resize',
      height: document.documentElement.scrollHeight
    }, '*');
  };
  new ResizeObserver(sendHeight).observe(document.body);
  sendHeight(); // 首帧立即发送
}

// functions.php
add_action('wp_footer', function () {
  if (!is_singular()) return;
  ?>
  [/span>script
  (function(){
    const iframe = document.querySelector('iframe【data-resize】');
    if (!iframe) return;
    window.addEventListener('message', e => {
      if (e.data?.type === 'resize') {
        iframe.style.height = e.data.height + 'px';
      }
    });
  })();
  script
  
});

[/span>iframe src="https://example.com/form" data-resizeiframe

(function () {
  if (window.parent === window) return; // 防止独立打开时报错
  const send = () => {
    window.parent.postMessage({
      type: 'resize',
      height: Math.max(
        document.body.scrollHeight,
        document.documentElement.scrollHeight
      )
    }, '*');
  };
  const observer = new ResizeObserver(send);
  observer.observe(document.body);
  window.addEventListener('load', send); // 图片懒加载后重新计算
})();

[/span>script src="/child.js" deferscript

add_action('wp_footer', function () {
  ?>
  [/span>script
  (function () {
    const iframes = document.querySelectorAll('iframe【data-auto-resize】');
    if (!iframes.length) return;

    const resizeMap = new WeakMap(); // 防止重复绑定

    const onMessage = (event) => {
      if (event.data?.type !== 'resize') return;
      for (const iframe of iframes) {
        if (iframe.contentWindow === event.source) {
          iframe.style.height = event.data.height + 'px';
          break;
        }
      }
    };

    window.addEventListener('message', onMessage);
  })();
  script
  
});

[/span>iframe src="https://example.com/form" data-auto-resizeiframe