I’m reading several feeds where free articles and articles behind a paywall are mixed. Since I’m only interested in the free articles I would like to filter the premium articles. Is this even possible? Perhaps via a custom site config?
We don’t yet have a good filtering system set up to handle this in Full-Text RSS. But you should be able to make use of what we implemented some time ago for excluding native ads from the feed result.
For example, in the site config file for the site in question you would add:
native_ad_clue: [XPath]
Where [XPath] identifies an element that only matches on paywalled articles, not regular ones. In the config file you can then set $options->remove_native_ads = true;
Another option is to use the filter feeds page on Feed Creator and give it the Full-Text RSS output. But then you’d have to see if there’s anything in the Full-Text RSS output you can use to filter the unwanted items.