Use same filter for several pipes on Yahoo! Pipes

Question

In Yahoo! Pipes I want to use one master pipe that runs some filters for RSS feeds.

These filters should then be used in individual pipes for RSS feeds I create.

Example:

• Filter-Pipe: Filter out iPhone, iPad, iOS ... (http://dl.dropbox.com/u/257805/filter-pipe.png)

• Pipe for Lifehacker RSS-Feed: Get Feed and apply the filters from "Filter-Pipe" (http://dl.dropbox.com/u/257805/rss-pipe.png)

• Pipe for MakeUseOf RSS-Feed: Get Feed and apply the filters from "Filter-Pipe"

So I only need to update one pipe containing all the filters. Seems that the Loop-Module won't work here.

Is that possible?

Answer 1

I do something similar with some of my pipes.

If you want a single feed as your output:

1. Use the Fetch Feed component from the Sources category to retrieve the feeds. A single instance of it can retrieve more than one feed.
2. If you need more than one source (eg. if you want to use other pipes as sources via the "My Pipes" category), use the Union component to join them into one.
3. Apply your filters to the Union's output. (eg. Connect the union's output to your filter pipe and then connect the output from that to your master pipe's output)

If you want individual feeds:

1. Create your filter pipe.
2. Create one pipe for each feed and use your filter pipe as a component by picking it from the "My Pipes" category.

Update: I'm not sure whether it's possible to set up a pipe which takes the output of another pipe as input, but for your needs, you can still use your filter pipe idea.

Just start your filter pipe off with a User inputs > URL Input component which sends its output to the Sources > Fetch Feed component's URL field.

If all you want is to filter various different feeds, you won't even need a parent pipe since using stuff from User inputs lets you use your pipe multiple times with different inputs.

Here's how I'd implement that filter pipe you show in your screenshot... including condensing a few of the filters using regular expression matching:

http://pipes.yahoo.com/ssokolow/filter_example_for_webapps_20324

If you still want to use a parent pipe for some further processing, you can just use that instead of "Fetch Feed" in the parent pipe.