chrome.storage.sync vs chrome.storage.local

google-chrome, google-chrome-extension

Solution

Whoops!

The problem was I was trying to sync data that exceeded in size. (4096 Bytes per item)

I wasn't getting `chrome.runtime.lastError` because I was mistakenly putting it inside the `get` function scope, instead of the `set` function which was producing the error. Hence, I'm posting this answer so it might help others who share the same confusion.

You should check `chrome.runtime.lastError` inside each api call, like so:

chrome.storage.local.set(objectToStore, function(data)
{
   if(chrome.runtime.lastError)
   {
       /* error */
       console.log(chrome.runtime.lastError.message);
       return;
   }
  //all good. do your thing..
}

This ran OK with `chrome.storage.local` because according to the docs you only have this limitation with `sync`.

printing `chrome.runtime.lastError` gave me: `Object {message: "QUOTA_BYTES_PER_ITEM quota exceeded"}`

Problem

I was trying to understand how to use the chrome.storage.api. I have included the following in my `manifest.json`: ``` "permissions": [ "activeTab","storage" ], ``` Than, I opened a new tab with the devtools and switched the `<page context>` to the one of my chrome-extension. Than I typed: ``` chrome.storage.sync.set({"foo":"bar"},function(){ console.log("saved ok"); } ); ``` and got: ``` undefined saved ok ``` Than I tried getting this stored value: ``` chrome.storage.sync.get("foo",function(data){ console.log(data); } ); ``` but this got me: ``` undefined Object {} ``` Than I did the same, but instead of `sync` I used `local` and this worked as expected: ``` chrome.storage.local.set({"foo":"bar"},function(){ console.log("saved ok"); } ); ``` ..and the retrieval: ``` chrome.storage.local.get("foo",function(data){ console.log(data); } ); ``` Which got me: `Object {foo: "bar"}` as it should. Is this because I am not signed in to my account on chrome? But in that case, isn't `chrome.storage.sync` designed to fallback into storing the data locally? EDIT Strangely, when i type this straight on console it seems to be working, but this code doesn't run from background.js code inside a click listener: ``` var dataCache = {}; function addStarredPost(post) { var id = getPostId(post); var timeStamp = new Date().getTime(); var user = getUserName(); dataCache[id] = {"id":id,"post":post,"time":timeStamp,"user":user}; chrome.storage.sync.set(dataCache,function(){ console.log("Starred!");}); } ``` After this is ran, `chrome.storage.sync.get(null,function(data){ console.log(data); });` returns an empty object as if the data wasn't stored. :/ This code seems to be working perfect with `chrome.storage.local` instead. `chrome.runtime.lastErros` returns `undefined`

Original source