Objective-c - Check timestamp of a URL (file)

Question

Given I have a URL like http://www.example.com/example.json

And I would like to check the last modified timestamp of example.json. Is there a way to do this with Objective-C?

Answer 1

Bottom line is there isn't a guaranteed way. There is a Last-Modified header that you can examine in your NSHTTPURLResponse, but per the RFC it is optional.

Answer 2

Checkout – allHeaderFields of NSHTTPURLResponse.