Whats the best way to add listener to external resource?
If you can add some hook, when external resource updated, you can use it.
But if it is impossible - on way to do it is create periodical task for checking external resources (Last-Modified header for example).
I have a django project and external resource. The external resource has XML data which changes time to time but it still static if nothing happened. I need to collect new data if something happened.
The ways I see:
1. Grab content one time in some period and check if it is different.
2. Save content as file and check length (worse way).
Unfortunately, I can't predict when content will change also I can't use WebSockets, Long Polling and WebHooks.
Please, describe me the ways that in modern WWW today may solve my problem!