17. The system of claim 16 further comprising: in response to receiving the request for the document from the client application: determining a caching status of the document with respect to a client cache; and when the caching status of the document is not fresh, submitting a retrieval request to the server for the document.
19. The system of claim 17 , wherein the caching status of the document in the client cache determined to be not fresh when the document is in the client cache and is stale.