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AnyEvent::Feed - Receiving RSS/Atom Feed reader with XML::Feed


Version 0.2


   use AnyEvent;
   use AnyEvent::Feed;

   my $feed_reader =
      AnyEvent::Feed->new (
         url   => '',

   $feed_reader->fetch (sub {
      my ($feed_reader, $new_entries, $feed, $error) = @_;

      if (defined $error) {
         warn "ERROR: $error\n";

      # $feed is the XML::Feed object belonging to that fetch.

      for (@$new_entries) {
         my ($hash, $entry) = @_;
         # $hash a unique hash describing the $entry
         # $entry is the XML::Feed::Entry object of the new entries
         # since the last fetch.

   # Or:

   my $feed_reader =
      AnyEvent::Feed->new (
         url      => '',
         interval => $seconds,

         on_fetch => sub {
            my ($feed_reader, $new_entries, $feed, $error) = @_;

            if (defined $error) {
               warn "ERROR: $error\n";

            # see above


This module implements some glue between AnyEvent::HTTP and XML::Feed. It can fetch a RSS/Atom feed on a regular interval as well as on customized times. It also keeps track of already fetched entries so that you will only get the new entries.


$feed_reader = AnyEvent::Feed->new (url => $url, %args)

This is the constructor for a new feed reader for the RSS/Atom feed reachable by the URL $url. %args may contain additional key/value pairs:

interval => $seconds

If this is set you also have to specify the on_fetch callback (see below). It will try to fetch the $url every $seconds seconds and call the callback given by on_fetch with the result.

headers => $http_hdrs

Additional HTTP headers for each GET request can be passed in the $http_hdrs hash reference, just like you would pass it to the headers argument of the http_get request of AnyEvent::HTTP.

username => $http_user
password => $http_pass

These are the HTTP username and password that will be used for Basic HTTP Authentication with the HTTP server when fetching the feed. This is mostly sugar for you so you don't have to encode them yourself and pass them to the headers argument above.

on_fetch => $cb->($feed_reader, $new_entries, $feed_obj, $error)

This callback is called if the interval parameter is given (see above) with the same arguments as the callback given to the fetch method (see below).

entry_ages => $hash

This will set the hash which keeps track of seen and old entries. See also the documentation of the entry_ages method below. The default will be an empty hash reference.

max_entry_age => $count

This will set the maximum number of times an entry is kept in the entry_ages hash after it has not been seen in the feed anymore. The default value is 2 which means that an entry hash is removed from the entry_ages hash after it has not been seen in the feed for 2 fetches.


Just returns the url that this feed reader is fetching from.

$feed_reader->entry_ages ($new_entry_ages)
my $entry_ages = $feed_reader->entry_ages

This will set the age hash which will keep track of already seen entries. The keys of the hash will be the calculated hashes of the entries and the values will be a counter of how often they have NOT been seen anymore (kind of an age counter). After each fetch this hash is updated and seen entries get a value of 0.

$feed_reader->fetch ($cb->($feed_reader, $new_entries, $feed_obj, $error))

This will initiate a HTTP GET on the URL passed to new and call $cb when done.

$feed_reader is the feed reader object itself. $new_entries is an array reference containing the new entries. A new entry in that array is another array containing a calculated hash over the contents of the new entry, and the XML::Feed::Entry object of that entry. $feed_obj is the XML::Feed feed object used to parse the fetched feed and contains all entries (and not just the 'new' ones).

What a 'new' entry is, is decided by a map of hashes as described in the entry_ages method's documentation above.


Robin Redeker, <>






Known Bugs

There is actually a known bug with encodings of contents of Atom feeds. XML::Atom by default gives you UTF-8 encoded data. You have to set this global variable to be able to use the XML::Feed::Entry interface without knowledge of the underlying feed type:

   $XML::Atom::ForceUnicode = 1;

I've re-reported this bug against XML::Feed, as I think it should take care of this. XML::Atom should probably just fix it's Unicode interface, but it seems to be a bit deserted w.r.t. fixing the bugs in the tracker.


Please report any bugs or feature requests to bug-anyevent-feed at, or through the web interface at I will be notified and then you'll automatically be notified of progress on your bug as I make changes.


You can find documentation for this module with the perldoc command.

    perldoc AnyEvent::Feed

You can also look for information at:


Copyright 2009 Robin Redeker, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.