From e7f73e1fe52facfabf8eda990b80ea5b0076aef4 Mon Sep 17 00:00:00 2001
From: Glenn Rice <grice1@missouriwestern.edu>
Date: Wed, 13 Jul 2022 07:37:17 -0500
Subject: [PATCH] Make knowls wait until the page css has loaded before
 initializing.

This fixes issue https://github.com/openwebwork/webwork2/issues/1739.

In the PG problem editor, the page in the iframe is not displayed until
after the page loads.  As such the javascript getComputedStyle method
fails.  The same things happens with the graphtool.  The same solution
is now implemented for knowls.
---
 htdocs/js/apps/Knowls/knowl.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/htdocs/js/apps/Knowls/knowl.js b/htdocs/js/apps/Knowls/knowl.js
index bdfcbac8c4..57b8388a40 100644
--- a/htdocs/js/apps/Knowls/knowl.js
+++ b/htdocs/js/apps/Knowls/knowl.js
@@ -15,6 +15,11 @@
 	};
 
 	const initializeKnowl = (knowl) => {
+		if (getComputedStyle(knowl)?.display === '') {
+			setTimeout(() => initializeKnowl(knowl), 100);
+			return;
+		}
+
 		knowl.dataset.bsToggle = 'collapse';
 		if (!knowl.knowlContainer) {
 			knowl.knowlContainer = document.createElement('div');