Feature Request: Use token in endpoint URL to pass the last fetch date to the API

[jamealg]

We're planning to use FeedMe to sync hundreds of items from a remote API and we'd like to avoid re-syncing the entire thing at a frequent interval. We can pass a date_modified_after parameter to our API that will fetch only items that were created/modified after a certain date. It would be really neat if FeedMe could pass the date of the previous run each time the feed is run.

For example, a feed could be configured with the following URL:
http://myfeed.com/api.json?date_modified_after={date_last_fetched}

When it runs the first time, it could be left blank:
http://myfeed.com/api.json?date_modified_after=

And the second time it would include the date from the previous time it was run:
http://myfeed.com/api.json?date_modified_after=2018-07-18

[weotch]

This would also be handy for Google Calendar feeds and it's syncToken or timeMin parameter.

[weotch]

While not totally related to the OP, I was able able to make a dynamic Feed URL by using aliases. In my general.php config file I have:

'aliases' => [
  '@calendarFeed' => 'https://www.googleapis.com/calendar/v3/calendars/CALENDAR_ID/events?'.
    'key=API_KEY&singleEvents=true&orderBy=startTime&timeMin='.date('Y-m-d\TH:i:s\Z'),
],

And then in FeedMe, just: