Yahoo Pipes how to truncate items per feed with mu

问题:

I have a Yahoo Pipe where I bring in a number of feeds via an OPML file. Rather than using truncate to limit the resulting number of items that get exported, I want to limit the number of items on a per feed basis. So if I have 60 feeds I want the latest 20 items from each one, not the latest 20 from the combined feeds.

回答1:

You can do this by creating 2 pipes:

1. A pipe that fetches a feed (one of the 60), and truncates after 20 items
2. Another that loops over feed URLs, and for each URL calls the first pipe

Here's an example of the first pipe:

http://pipes.yahoo.com/pipes/pipe.info?_id=f6d1e5fa8873064f0265352e9ea9cd34

Here's an example of the second:

http://pipes.yahoo.com/pipes/pipe.info?_id=4b86c5d956b2f99a460a0520ff8c55b2