From 6bdb14f3a6b306039afcb7b9a75298b02aedfe10 Mon Sep 17 00:00:00 2001
From: James J Balamuta <james.balamuta@gmail.com>
Date: Fri, 26 Jan 2024 20:05:28 -0800
Subject: [PATCH] Guard against the custom package not being available by first
 checking if the package is present and, then, loading it.

---
 _extensions/webr/qwebr-document-engine-initialization.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/_extensions/webr/qwebr-document-engine-initialization.js b/_extensions/webr/qwebr-document-engine-initialization.js
index 9ff0fbd3..835367f8 100644
--- a/_extensions/webr/qwebr-document-engine-initialization.js
+++ b/_extensions/webr/qwebr-document-engine-initialization.js
@@ -5,7 +5,7 @@ async function qwebrInstallRPackage(packageName) {
 
 // Function to load a single package
 async function qwebrLoadRPackage(packageName) {
-  await mainWebR.evalRVoid(`library(${packageName});`);
+  await mainWebR.evalRVoid(`if(requireNamespace('${packageName}', quietly = TRUE)) { library(${packageName}); }`);
 }
 
 // Generic function to process R packages