I have a Craft 2 project which is using an older version of the FeedMe plugin 1.x. In order to use a specific XML feed, a custom XML feed service was implemented with a custom feed type available in Craft, but this involved directly editing the FeedMe plugin files. The reason for this is because a specific authentication mechanism is required before being able to interact with the feed in the form of a unique token passed by the Authorization HTTP header to an auth endpoint first.

I noticed with FeedMe 2.x a lot of improvements have been made. Does anyone have experience with extending the existing XML service for such a purpose?

The current implementation added an additional service within `feedme/services/` which extends `FeedMe_FeedXMLService` to handle the authorisation part and added an additional record type. In theory could a separate plugin be created that provides the service without having to modify the core plugin?