https://hypo.org/modules/contrib/iframe/js/iframe.js?v=10.5.3

1/**
2 * @file
3 * See Issue "autoresize" https://www.drupal.org/node/360549.
4 */
5(function ($) {
6  Drupal.behaviors.iframeModule = {
7    attach(context, settings) {
8      $('iframe.autoresize').each(function () {
9        const offsetHeight = 20;
10        const thisIframe = $(this);
11        let iframeWaitInterval;
12        let elem;
13        let msg = '';
14
15        function resizeHeight(iframe) {
16          if ($(iframe).length) {
17            /* Iframe yet loaded ? */
18            const iframeDoc =
19              $(iframe)[0].contentDocument ||
20              $(iframe)[0].contentWindow.document;
21            let contentheight = 0;
22
23            try {
24              contentheight = $(iframeDoc).find('body').height();
25            } catch (e) {
26              elem = $(iframe)[0];
27              msg = $(
28                `<p><small>(${Drupal.t(
29                  'Iframe URL is not from the same domain - autoresize not working.',
30                )})</small></p>`,
31              );
32              $(elem).after(msg);
33              clearInterval(iframeWaitInterval);
34            }
35
36            if (contentheight > 0) {
37              clearInterval(iframeWaitInterval);
38              try {
39                const frameElement = $(iframe)[0].frameElement || $(iframe)[0];
40                frameElement.style.height = `${contentheight + offsetHeight}px`;
41                frameElement.scrolling = 'no';
42              } catch (e) {
43                /* here, ist not a correctable error */
44              }
45            }
46          }
47        }
48        const delayedResize = function () {
49          resizeHeight(thisIframe);
50        };
51
52        iframeWaitInterval = setInterval(delayedResize, 300);
53      });
54    },
55  };
56})(jQuery);