Why isn’t this existing yet? Or is it just that I cannot find it?
There are a number of generic RSS transformations that may be generalized and made available as an online services library.
A typical transformation that I’m looking for is filtering a feed based on keywords, to eliminate items that (reduced to plain text) match some custom regular expression. I’m using page2rss.com for creating RSS feeds that list updates to a website, but page2rss cannot distinguish between content changes and e.g. the ever-changing date-of-today that is printed on the same webpage. Most of the page2rss feed items are meaningless, because they only mention the changed date. By routing the generated feed through an online RSS filtering service, provided with a regex for the date stamp, I could obtain a feed that only lists the meaningful items.
The service would be called using the http protocol. The service itself could be a perl script (or any other CGI script) residing on the library server (e.g. “http://rss-services-library.com/filterRSS.cgi” ). The arguments to the service are the original feed (e.g. “http://page2url.com/page?url=www.google.com/”), the regex for the date print and the filter mode (options for matching title, description,…, for matching whole item or part of the item, for matching plain text or html-formatted content, for returing matching items or returning non-matching items, etc…). These arguments are provided as CGI parameters, either POST or GET.
No, I’m fooling myself! There must be a kind of service model like this around !?