List Media Uploads

Retrieves the photo changes still queued or failed for a location.

This is how you follow an asynchronous submission, since there's no completion callback. Read the response as a whole rather than item by item:

• Anything PENDING or UPLOADING means the queue is still working. Don't report results yet.
• Only FAILED items means the queue finished and those items didn't make it.
• An empty response means nothing is outstanding for this location.

Read that last one carefully, because it's weaker than it looks. It tells you the queue is empty, not that a particular submission succeeded. A successful change leaves nothing behind, and so does a failure that's been cleared, and the two are indistinguishable afterwards. Google's own media list is the record of what's actually live, so confirm against List Media rather than inferring success from an empty queue.

Failures are cleared for the whole location by the next call to Bulk Create Media Uploads, whoever makes it. If more than one app manages the same location, one app queuing a change clears failures the other hasn't read yet. Read failures before queuing again, and don't treat an empty response as proof that your own submission worked.

You can also use this to show a gallery matching what the site owner asked for while the queue is still working, because Google's list lags behind in both directions. Count only changes still on their way, since a FAILED addition never reached Google:

The response is never paged and never truncated. It returns the complete set or fails with FAILED_PRECONDITION.