Google Reader - Keeping Read Item state in Sync

What is the best way to manage cached articles when it comes to keeping the read state/unread state in sync? Is there a property inside the article feed that will tell me the state of the item? I'm trying to figure out how to keep the read state in sync, and if I need to do a comparison of every cached article to the one on Google Rea开发者_如何学运维der.

So far I've only been requesting unread items, so I exclude anything that's already been marked as read. However, I might have some cached articles unread on the client that have been marked as read on Google Reader. Those articles won't be downloaded again, but I'd like to perhaps do a check on launch of each unread article, to see if it should still be displayed as unread.

Thanks for your time

There's no reader API, so I believe you're stuck with re-fetching the 'unread items' feed repeatedly, and removing any items that are no longer present in it. As far as seeing the status of items that are too old to be in the feed, I'm not sure if there's a practical way to do that at all.

I'm not sure what you're trying to accomplish, but bear in mind that, given the lack of an API, there's no way for you to mark an item as read, either.