Fallback if localStorage is not available.

[gyurielf]

Hello there!

I met a quite edge case issue while using the package.

In chrome, if you have an embed iframe on a site (which uses this package), and you open it in incognito mode it will be throws an error.
Failed to read the 'localStorage' property from 'Window': Access is denied for this document.
I walked around the issue, so it's a chrome specific issue which is exists on both mobile and desktop (tested on win, ubuntu, android),

I tried to handle on the the lacking of localStorage in a +page.ts load and throwing the user to a meaningful error page, but files are loaded by the browser when the document load starts and it's try to "connect" to the localStorage instantly and unfortunately it's kill the app before it can be handled by a svelte-kit load function.

I thought about a fallback option or something like that. I mean if it can't read the localStorage, drop a meaningful error but make a regular store regardless to prevent app breaks.

The title probably not too precise, so modify freely.

Best regards.

[gyurielf]

I look into the code and as I see you did something like that.

svelte-persistent-store/src/core.ts

Lines 286 to 292 in 584b57b

	export function createLocalStorage<T>(listenExternalChanges = false): StorageInterface<T> {
	if (typeof window !== "undefined" && window?.localStorage) {
	return getBrowserStorage(window.localStorage, listenExternalChanges)
	}
	warnStorageNotFound("window.localStorage")
	return createNoopStorage()
	}

Maybe it's a svelte-kit issue then ?

[MacFJA]

I never encountered this case before.
I will try to handle it like when the localStorage doesn't exist

---

Maybe it's a svelte-kit issue then ?

It's not an issue with SvelteKit, the issue came from the iframe being sandboxed by default.
You can use localStorage in an iframe, but you have to allow it before (https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe#sandbox)

[gyurielf]

Well, shame on me, but i forgot to mention that this issue occurs only on incognito mode, otherwise working perfectly.

[MacFJA]

I just push the version 2.3.0 that should fix this kind of errors

[gyurielf]

I've tested it, working like a charm. Thank you for the super fast reply and fix!