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PubSubHubbub


PubSubHubbub (PuSH) is a notification-based protocol for publishing and subscribing to streams and legacy feed files in real time. Currently there are no known indieweb sites that subscribe to anything using PuSH, but there are a few separate-UI indie-readers that subscribe to h-feed streams using PuSH.

Contents

Why

You should implement PuSH for your home page updates so that IndieWeb readers (like shrewdness, ) can:

  • promptly fetch your posts when you publish them
  • and avoid polling your server with unnecessary traffic

How

See: How to publish and consume PubSubHubbub

IndieWeb Examples

There are several indieweb sites producing PuSH notifications, and a few indieweb-centric applications that consume them (see in particular indie readers, Shrewdness and Woodwind).

Tantek

Tantek Çelik uses Falcon to send PuSH notifications from his site tantek.com

Aaron Parecki

Aaron Parecki uses p3k to send PuSH notifications from his site aaronparecki.com

  • 2012-08-18 through 2015-02-27 - PuSH 0.3 notification for every entry in his Atom feeds (notes, articles and replies). Using Google's appspot.com hub.
  • 2015-02-27 onward - PuSH 0.4 notification for every feed that is updated after a post is created, including h-entrys on home page, notes/articles/replies/etc pages, and tag pages. Using Superfeedr's hub.
  • 2015-03-26 - changed hub from Superfeedr to Switchboard

Bret Comnes

Bret Comnes sends PuSH notifications for his bret.io Github Pages/Jekyll Atom feed file since 2014-03-16.

Kyle Mahan

Kyle Mahan uses Red Wind to send PuSH notifications for new/edited posts and new mentions in his kylewm.com Atom feed file since 2014-03-23

  • Now also sending PuSH 0.4 notifications for updates to the main h-feed at kylewm.com, using a hub at superfeedr.com. Confirmed working 2015-02-21.

Barnaby Walters

Barnaby Walters uses Taproot to send PuSH notifications for each new post on his WaterPigs.co.uk homepage HTML feed using PuSH 0.4 and Google’s hub since 2014-03-25.

David Shanske

David Shanske uses WordPress and the PushPress plugin to send PuSH 0.3 notifications of his RSS feed updates since 2014-02-16.

Matthias Pfefferle

 Matthias Pfefferle uses WordPress and the PubSubHubbub Plugin (selfdogfooding) to send PuSH notifications since 2011-01-29.

  • PuSH 0.4 with h-entrys support since 2012

Christian Weiske

Christian Weiske sends PuSH 0.4 notifications since 2015-04-01 using his own hub, phubb.

Ben Werdmuller

Ben Werdmülller uses Known to send PuSH 0.4 notifications for each new post on his werd.io homepage HTML feed since at least 2015-05-04 (Known 0.7.8 release date).

Pelle Wessman

Pelle Wessman uses GitHub Pages + Superfeedr to send PuSH notifications from his site voxpelli.com

Andy Leap

Andy Leap sends PuSH 0.4 notifications for Vendaria.net since 2015-05-16

1000s of Known Sites

1000s of *.withknown.com sites send PuSH 0.4 notifications for each new post on their homepages's HTML feed since at least 2015-05-04 when Known 0.7.8 shipped with reliable PuSH 0.4 support.

There are also numerous (hundreds?) of Known installs that are also all likely running Known 0.7.8 or later and thus send PuSH 0.4 notifications.

Consuming Implementations

The following implementations consume and subscribe to PuSH feeds:

PuSH 0.4:

PuSH 0.3:

How To

Publish and Consume a PuSH-enabled feed

PuSH 0.4 goes beyond previous versions to allow publishers to send push notifications for any HTTP resource (e.g. h-feeds). You should use the newer spec, 0.4. PuSH 0.3 supported push notifications only for legacy XML feed files.

See the main article: How to publish and consume PubSubHubbub.

WordPress Plugins for PuSH

There is a plugin called "PushPress" which you can install on your self-hosted WordPress install.

An alternative, that also supports PubSubHubbub v0.4, is the PubSubHubbub Plugin.

If you're using WordPress.com, they already support PuSH by default (likely using that plugin).

Subscribing to Fragments

Superfeedr also offers the unique ability to subscribe to fragments on a page, using the # symbol. For example, if you subscribe to http://tantek.com/#.hentry, you will receive POST to your webhook/callback endpoint with the content of the first element of class "hentry" on http://tantek.com/

This should be seen as an optimization. A minimal consumer can simply re-fetch the resource itself when it receives a ping.

Testing your PuSH-enabled feed

There are several ways you can test whether or not your PuSH feed and pings are working properly:

Testing PuSH 0.4

  1. Subscribe to your home page in one of these indie readers:
  2. Publish a new post and send a PuSH 0.4 notification
  3. Watch the reader to see if your post shows up - it should show up in seconds or less.

Testing PuSH 0.3

RSS Reader

Most popular RSS Readers do implement PubSubHubbub, you can just subscribe to your feed on one of them, and see if the update as been propagated after you added content.

Status.net

  1. subscribe to your home page from a Status.net account
  2. publish stuff on your home page
  3. see updates appear in real time on your Status.net account

Bots

There are several XMPP/IRC bots which allow you to subscribe to feeds and be notified of updates via any XMPP or IRC client. You’ll need an XMPP account, or an IRC client.

Notifix

Notifix is a bot (see above for source code). It's constantly connected to irc.freenode.net. Send him a private message like +help to see available commands. Subscribe with +subscribe <feed>, publish your content and see if you get the ping straight via IRC.

  • I have had better experiences with notifixlite than PuSH Bot --Waterpigs.co.uk 03:16, 5 June 2013 (PDT)

Testing your PuSH Subscriber

  • http://push-pub.appspot.com/ is a useful application for testing your subscribing code. This is a known-working PuSH 0.4 publisher, so you can subscribe to it, post an update, and confirm that you received a ping from its hub.

Hubs

See https://github.com/pubsubhubbub/PubSubHubbub/wiki/Hubs for more of them.

Testing your hub

push-tester is a tool that mimicks a blog with h-feed and h-entry and allows posting new articles with a single click. A configurable PuSH hub is notified about the new post.

Public instance: http://push-tester.cweiske.de/

Discussion

Discussion about PubSubHubbub primarily occurs on the GitHub repo, but there's also a W3C community group:

Brainstorming

How can we support PuSH consumers that do not have a publicly routable URL, such as devices behind a firewall or NAT? Maybe a hub or an external service could provide an alternative subscription mechanism such as websockets or eventsource, which could then make the PuSH subscription on behalf of the consumer. Aaron Parecki 12:32, 26 May 2015 (PDT)

Issues

Too Complex

In the past (2013 era) there was controversy about PubSubHubbub being too complex for the indieweb. Since then numerous indieweb sites support PuSH notifications of their published content, and we have a few new PuSH hubs built and maintained by indieweb folks, as well as readers subscribing to PuSH updates. The below is left as historical record of a past issue.

FAQ

Q: How do I update the hub I am using and ensure subscribers update accordingly?

A: Subscribers should poll occasionally to see if the hub has been updated. You can list and ping both hubs for a while to speed up the process. [1]. Also, hubs should actually notify the hub URL (as part of the discovery links) which means that subscribers will know about the designated hubs with every notification, making it completely optional to have a "routine" polling. It's considered good practice when a feed/publisher changes its hub to have a period during which it *also* pings the old hub (even after the discovery link was removed).

See Also