The engineers over at Yahoo came up with a solution: Yahoo! Pipes. Pipes allows you to set up a series of, well, pipes, for your data to go through, each manipulating it slightly, until you have processed your raw data into what you wanted to extract in the format you want it.
Just to give a simple example of what Pipes can do: Say I wanted to create a feed for my users that contained all my posts, except those that contain the word “task”. In order to do this before Pipes, I would have to write up a new PHP script that would fetch all my articles from the database, filter out those with “task” in them, and create a whole new RSS document. Replicating large portions of the code that renders my current feed. Or, I could change my current RSS feed generator so that it accepted URL arguments that allowed filtering by words. All of this would require me both to edit files on my server and make my scripts more complex.
With Yahoo! Pipes, I can simply set my feed as the input source using feed auto-discovery, set up a filter to block items containing “task”, and output the resulting elements as RSS XML. Done!
You can see my pipe for doing this at: http://pipes.yahoo.com/jonhoo/nontaskblog
Oh, and did I mention you can publish pipes…? ;)
PS: If you want to fetch the feed form a Wordpress blog, notice that you should not input the feed URL directly, but rather select the source to be “Site Feed”, and then input the URL for the front page of your blog.