From a4709f5b91aaafd13b69102c8826f1d8721411d8 Mon Sep 17 00:00:00 2001
From: Mateusz Uzdowski <mateusz@silverstripe.com>
Date: Fri, 9 Aug 2019 11:16:41 +1200
Subject: [PATCH] Update for jQuery 3.

---
 javascript/iframe_page.js | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/javascript/iframe_page.js b/javascript/iframe_page.js
index e0ab968..c3629ef 100644
--- a/javascript/iframe_page.js
+++ b/javascript/iframe_page.js
@@ -9,26 +9,27 @@ if (typeof jQuery!=='undefined') {
 		iframe.hide();
 		loading.show();
 
-		$(function() {
-			$( window ).load(function() {
-				// Iframe content has been loaded
-				loading.hide();
-				iframe.show();
+		$( iframe ).on('load', function() {
+			// Iframe content has been loaded
+			loading.hide();
+			iframe.show();
 
-				if (iframe.hasClass('iframepage-height-auto')===true) {
-					// Try to set the height to the height of the iframe content (only possible if it is the same domain)
-					try {
-						var iframeInsideSize = $(iframe[0].contentWindow.document.body).height();
-						iframe.css('height', (parseInt(iframeInsideSize)+100)+'px');
-					}
-					catch(e) {
-						// Failed to set the height, we fall back to default css height.
-					}
+			if (iframe.hasClass('iframepage-height-auto')===true) {
+				// Try to set the height to the height of the iframe content (only possible if it is the same domain)
+				try {
+					// Use plain JS to get iframe size. There is some timing issue with jQuery
+					// which causes the iframe size to be 0 even after iframe.show().
+					const domframe = document.querySelector('#Iframepage-iframe');
+					var iframeInsideSize = domframe.contentWindow.document.body.offsetHeight;
+					iframe.css('height', (parseInt(iframeInsideSize)+100)+'px');
 				}
+				catch(e) {
+					// Failed to set the height, we fall back to default css height.
+				}
+			}
 
-				// Finally, remove the marker
-				iframe.removeClass('iframepage-not-ready');
-			});
+			// Finally, remove the marker
+			iframe.removeClass('iframepage-not-ready');
 		});
 	})(jQuery);
 }