From 6f5f9ca2fba2b3da51fe2c79f770a36f8df9ce73 Mon Sep 17 00:00:00 2001
From: Jermolene <jeremy@jermolene.com>
Date: Sun, 3 Feb 2019 17:29:32 +0000
Subject: [PATCH] Browser-storage: Handle quota exceeded error

---
 .../tiddlywiki/browser-storage/rawmarkup.js   |  2 --
 plugins/tiddlywiki/browser-storage/readme.tid |  4 +++-
 plugins/tiddlywiki/browser-storage/startup.js | 22 +++++++++++++++++--
 3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/plugins/tiddlywiki/browser-storage/rawmarkup.js b/plugins/tiddlywiki/browser-storage/rawmarkup.js
index 7aa273211..b4dafbc99 100644
--- a/plugins/tiddlywiki/browser-storage/rawmarkup.js
+++ b/plugins/tiddlywiki/browser-storage/rawmarkup.js
@@ -28,7 +28,6 @@ function hookBootTiddlersLoaded() {
 	for(var index=0; index<window.localStorage.length; index++) {
 		var key = window.localStorage.key(index),
 			parts = key.split("#");
-console.log("key",key)
 		// If it's ours
 		if(parts[0] === "tw5" && parts[1] === url) {
 			// Read it as JSON
@@ -45,7 +44,6 @@ console.log("key",key)
 						// Get any existing tiddler
 						var title = incomingTiddler.fields.title,
 							existingTiddler = $tw.wiki.getTiddler(title);
-console.log("Existing",title,existingTiddler,existingTiddler && existingTiddler.isEqual(incomingTiddler))
 						if(existingTiddler && existingTiddler.isEqual(incomingTiddler)) {
 							// If the incoming tiddler is the same as the existing then we can delete the local storage version
 							window.localStorage.removeItem(key);
diff --git a/plugins/tiddlywiki/browser-storage/readme.tid b/plugins/tiddlywiki/browser-storage/readme.tid
index 1e0fc1521..9b2fd664b 100644
--- a/plugins/tiddlywiki/browser-storage/readme.tid
+++ b/plugins/tiddlywiki/browser-storage/readme.tid
@@ -13,6 +13,8 @@ Browser local storage is not a panacea for TiddlyWiki:
 
 Please use this plugin with caution. There are a number of unresolved issues and open questions:
 
-* An "red screen of embarrassment" error is raised when local storage is full
+* A somewhat user hostile error is raised when local storage is full
 * Innerwikis read the local storage of their parent wikis
 * This plugin does not interfere with the existing saver mechanism, so you'll still get warnings when refreshing the page, even if your changes are safely committed to local storage
+* Deleted tiddlers will be restored when the wiki is refreshed
+
diff --git a/plugins/tiddlywiki/browser-storage/startup.js b/plugins/tiddlywiki/browser-storage/startup.js
index dd8ceab49..ba77a284b 100644
--- a/plugins/tiddlywiki/browser-storage/startup.js
+++ b/plugins/tiddlywiki/browser-storage/startup.js
@@ -21,14 +21,32 @@ exports.synchronous = true;
 exports.startup = function() {
 	// Compute our prefix for local storage keys
 	var url = window.location.protocol === "file:" ? window.location.pathname : "",
-		prefix = "tw5#" + url + "#"
+		prefix = "tw5#" + url + "#";
+	// Make a logger
+	var logger = new $tw.utils.Logger("browser-storage",{
+			colour: "cyan"
+		});
 	// Track tiddler changes
 	$tw.wiki.addEventListener("change",function(changes) {
 		$tw.utils.each(changes,function(change,title) {
+			// Get the tiddler
 			var tiddler = $tw.wiki.getTiddler(title);
 			if(tiddler) {
+				// Get the JSON of the tiddler				
 				var json = JSON.stringify(tiddler.getFieldStrings());
-				window.localStorage.setItem(prefix + title,json);
+				// Try to save it to local storage
+				try {
+					window.localStorage.setItem(prefix + title,json);
+				} catch(e) {
+					if(e.name === "QuotaExceededError") {
+						// Complain if we failed
+						logger.alert("Quota exceeded trying to store '" + title + "' in browser local storage");
+						// No point in keeping old values around for this tiddler
+						window.localStorage.removeItem(prefix + title);
+					} else {
+						throw e;
+					}
+				}
 				console.log("browser-storage: Saving",title);
 			} else {
 				window.localStorage.removeItem(prefix + title);