Access localStorage of a WebView from native code

Question

My application stores web pages for offline access using a WebView.

I need to access the cached images of those pages via native code.

I first tried (unsuccessfully) reading ApplicationCache.db, but according to this answer, it's not a good idea, since the database format changes between Android versions.

I had an idea of using localStorage on my web page. Is it possible to access the stored information from native code?

Answer 1

On Android 4.4, you could use the WebView.evaluateJavascript API to get a result back from a javascript snippet, i.e. you could interrogate localStorage and parse the result returned. Prior to 4.4, I think using a JS bridge will be your only reasonable option. I guess you'd hook up the bridge to a StorageEvent listener in your javascript (this approach would work in 4.4, too).