My app caches Google Docs files locally and needs to update them then whey change. When I request a changes feed, the results include all items that have changed, regardless of the type of change. I only need to re-download those items whose actual content has changed; I don't need to download documents that have merely been shared with somebody new or otherwise had their metadata changed. I know that you can request that expanded ACL data be included in the changes feed, but that may not be sufficient if it will only help me detect permissions changes, and not other changes to metadata.
Is there a way to do this? The files that are being downloaded are quite large at times (5-10MB), and the accounts that I'm tracking frequently have thousands of files, so imagine my users' consternation if they're on a slow connection and my app suddenly has to re-download hundreds of files due to a simple change like a folder being shared with a new user.
Thanks!
Okay. I overlooked the simple answer hidden in the XML: there is a checksum element included in the docs feed for all documents.