NSURLSession Cache Policy
Before start NSURLSession cache policy, we should connect a remind to NSURLConnection vs NSURLSession concepts. NSURLConnection got its start a decade ago, with the original release of Safari in 2003 , as an abstraction on top of the Core Foundation / CFNetwork APIs. The name NSURLConnection actually refers to a group of the interrelated components that form the Foundation URL Loading System: NSURLRequest , NSURLResponse , NSURLProtocol , NSURLCache , NSHTTPCookieStorage , NSURLCredentialStorage , and its namesake, NSURLConnection . NSURLRequest objects are passed to an NSURLConnection object. The delegate (conforming to the erstwhile informal <NSURLConnectionDelegate> and <NSURLConnectionDataDelegate> protocols) responds asynchronously as an NSURLResponse , and any associated NSData are sent from the server. Before a request is sent to th...