From 26391efa26f6727ce10706e87897d33a753043d4 Mon Sep 17 00:00:00 2001
From: Wes Cossick <wes@nextstepwebs.com>
Date: Mon, 14 Mar 2016 20:59:16 -0500
Subject: [PATCH] Better localStorage detection

---
 src/js/simplemde.js | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/js/simplemde.js b/src/js/simplemde.js
index e277dbf..73e2089 100644
--- a/src/js/simplemde.js
+++ b/src/js/simplemde.js
@@ -1510,8 +1510,24 @@ SimpleMDE.prototype.render = function(el) {
 	this._rendered = this.element;
 };
 
+// Safari, in Private Browsing Mode, looks like it supports localStorage but all calls to setItem throw QuotaExceededError. We're going to detect this and set a variable accordingly.
+function isLocalStorageAvailable() {
+	if(typeof localStorage === "object") {
+		try {
+			localStorage.setItem("smde_localStorage", 1);
+			localStorage.removeItem("smde_localStorage");
+		} catch (e) {
+			return false;
+		}
+	} else {
+		return false;
+	}
+	
+	return true;
+}
+
 SimpleMDE.prototype.autosave = function() {
-	if(localStorage) {
+	if(isLocalStorageAvailable()) {
 		var simplemde = this;
 
 		if(this.options.autosave.uniqueId == undefined || this.options.autosave.uniqueId == "") {
@@ -1564,7 +1580,7 @@ SimpleMDE.prototype.autosave = function() {
 };
 
 SimpleMDE.prototype.clearAutosavedValue = function() {
-	if(localStorage) {
+	if(isLocalStorageAvailable()) {
 		if(this.options.autosave == undefined || this.options.autosave.uniqueId == undefined || this.options.autosave.uniqueId == "") {
 			console.log("SimpleMDE: You must set a uniqueId to clear the autosave value");
 			return;