From c506311787410c53ac9b9c87952fd43ba22c737a Mon Sep 17 00:00:00 2001
From: Mike Eling <mike.eling97@gmail.com>
Date: Tue, 4 May 2021 02:16:29 +0200
Subject: [PATCH] :bug: Fix crashes on SSR when detecting locale

---
 CHANGELOG.md         |  2 ++
 src/utils/methods.ts | 14 ++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1234aa1..0b8586d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@
 All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
+### Fixed
+- Crashes on SSR when detecting locale.
 
 ## [2.2.1] - 2021-05-03
 ### Changed
diff --git a/src/utils/methods.ts b/src/utils/methods.ts
index 47c2704..340cb9b 100644
--- a/src/utils/methods.ts
+++ b/src/utils/methods.ts
@@ -8,10 +8,20 @@ export const validateLocale = (l: string, p: RegExp) => {
   return Boolean(new RegExp(_p).test(l));
 }
 
+/**
+ * Detects the preferred locale and parses it.
+ * @returns Detected browser locale or null.
+ */
 export const detectDeviceLocale = () => {
-  const browserLocale = tryParseLocale(window.navigator.language);
+  let browserLocale = null;
+
+  if(window?.navigator?.language)
+    browserLocale = tryParseLocale(window.navigator.language)
+
+  if(window?.navigator?.languages?.length > 0)
+    browserLocale = tryParseLocale(window.navigator.languages[0]);
 
-  if(!browserLocale) console.warn("Locale not detected.");
+  if(!browserLocale) console.warn("Littera could not determine the preferred locale.");
 
   return browserLocale || null;
 }