Localstorage Support

Follow up issues for IndexDB and other types of storage when we get there.

Future Solutions

Proper API for deleting Localstorage by hostname (both of these bugs seem to want to extend the browsingData API)

Pros

• Clear localstorage by site rather than all or nothing
• Should be easily added to the extension code since it seems like the extended API uses a list of hostnames which Cookie Cleanup conveniently returns

Cons

• No support yet
• Unless there’s a way to enumerate all localstorage, there’s a way for this extension to miss some localstorage
  • Ex. A site that uses no cookies and only localstorage (as cookie cleanup outputs site names for cookies that have been deleted to be sent into the localstorage cleanup)
    • I find this very unlikely since almost all sites have cookies
  • Ex. A current Cookie AutoDelete user who upgrades to a version that supports deleting localstorage will have their existing localstorage still there
    • The user would have to clear all their localstorage after upgrade to get a “clean slate”

Firefox Blockers

• Extend browsingData to support removing localStorage by host

Chrome Blockers

• 78093

Current solutions

browsingData API

Pros

• Actual API for removing localstorage

Cons

• Not viable without the above bugs
• Current removalOptions only include the timeframe

Firefox Blockers

• Implement clearing of LocalStorage in browsingData API (Firefox 57+)

Inject a content script that clears localstorage on page load (courtesy of reddit)

Code:

window.localStorage.clear();
window.sessionStorage.clear();

Pros

• Works in all browsers
• Better than the current browsingData API
• Will work with the whitelists

Cons

• Seems very hackish and its only a workaround
• Localstorage stays until the user visits the website again
• Probably have to come up with an algorithm to find the diff of the current tabs (between page loads) and only inject if there is a change (otherwise the injection would happen every time on site navigation)
  • Because of this, this workaround will be on the backburner until I have some strategies about the best way to only inject the content script when it is needed

I’m thinking of doing the content script route as an experimental feature until the browsingData gets extended. Anyone else is free to give their input on how best to implement this.

[ke-d]

I implemented a basic implementation of localstorage cleaning.

Here are some things I noticed:

• C-AD will have to set a cookie for sites that don’t set cookies so that the cleanup “knows” that site’s cookies and localstorage should be cleaned when the tab closes
• Might not be compatible with containers enabled (needs more testing)
• It will not clear localstorage that was previously there (Maybe a deep clean option that uses your history to clear cookies and localstorage?)

[Solomon1732]

Citing it here for convenience. Excerpt from https://blog.mozilla.org/addons/2017/11/20/extensions-in-firefox-58/:

The browsingData API now supports clearing the indexedDB storage area The browsingData API supports clearing localStorage by hostname, similar to cookies