POE::Component::Client::NNTP::Tail - Sends events for new articles posted to an NNTP newsgroup

This documentation describes version 0.01.

   use POE qw( Component::Client::NNTP::Tail );
   use Email::Simple;

   POE::Component::Client::NNTP::Tail->spawn(
     NNTPServer  => 'nntp.perl.org',
     Group       => 'perl.cpan.testers',
   );

   POE::Session->create(
     package_states => [
       main => [qw(_start new_header got_article)]
     ],
   );

   POE::Kernel->run;

   # register for NNTP tail events
   sub _start {
     $_[KERNEL]->post( 'perl.cpan.testers' => 'register' );
     return;
   }

   # get articles with subject 'FAIL' as 'got_article' events
   sub new_header {
     my ($article_id, $lines) = @_[ARG0, ARG1];
     my $article = Email::Simple->new( join("\r\n", @$lines) );
     if ( $article->header('Subject') =~ /^FAIL/ ) {
       $_[KERNEL]->post( 
         'perl.cpan.testers' => 'get_article' => $article_id 
       );
     }
     return;
   }

   # find and print perl version components to terminal
   sub got_article {
     my ($article_id, $lines) = @_[ARG0, ARG1];
     for my $text ( reverse @$lines ) {
       if ( $text =~ /^Summary of my perl5 \(([^)]+)\)/ ) {
         print "$1\n";
         last;
       }
     }
     return;
   }

This component periodically polls an NNTP newsgroup and posts POE events to component listeners as new articles are available. These events contains the article ID and header text for the given articles. This component also facilitates retrieving the full text of a particular article of interest.

Internally, it uses POE::Component::Client::NNTP to manage the NNTP session.

Spawn a new component session for each newsgroup to follow. Send the register event to specify an event to sent back when new articles arrive. Handle the new article event. Optionally, send the get_article event to request the full text of the article.

   POE::Component::Client::NNTP::Tail->spawn(
     NNTPServer  => 'nntp.perl.org',
     Group       => 'perl.cpan.testers',
   );

The spawn class method launches a new POE::Session to follow a given newsgroup. The NNTPServer and Group arguments are required, all other arguments are optional:

• NNTPServer (required) -- name or IP address of the NNTP server
• Group (required) -- newsgroup to follow
• Interval -- minimum number of seconds between checks for new messages (defaults to 60)
• Alias -- POE::Session alias name (defaults to the newsgroup name)
• Port -- server port for NNTP connections
• LocalAddr -- local address for outbound IP connection
• Debug -- if true, a trace of events and arguments will be printed to STDERR

You must spawn multiple times to follow multiple newsgroups.

The component will respond to the following events.

   $_[KERNEL]->post( 'perl.cpan.testers' => register => $event_name );

This event notifies the component to post a new_header event to the sender when new articles arrive. The event will be sent using the $event_name provided, or will default to 'new_header'. Multiple sessions may register with a single POE::Component::Client::NNTP::Tail session.

   $_[KERNEL]->post( 'perl.cpan.testers' => unregister );

This event will stop the component from posting new_header events to the sender.

   $_[KERNEL]->post( 
     'perl.cpan.testers' => get_article => $article_id => $event_name
   );

This event requests that the full text of $article_id be returned in a got_article event. The event will be sent using the $event_name provided, or will default to 'got_article'.

   $_[KERNEL]->post( 'perl.cpan.testers' => 'shutdown' );

This event requests that the component stop broadcasting events, disconnect from the NNTP server and generally stop processing.

The component sends the following events types, though the actual event name may be different depending on what is specified in the register and get_article events.

   ($article_id, $lines) = @_[ARG0, ARG1];

The new_header event is sent when new articles are found in the newsgroup. The $lines argument is a reference to an array of lines that contain the article header. Lines have had newlines removed.

   ($article_id, $lines) = @_[ARG0, ARG1];

The got_article event is sent when the full text of an article is retrieved. The $lines argument is a reference to an array of lines that contain the full article, including header and body text. Lines have had newlines removed.

Please report any bugs or feature using the CPAN Request Tracker. Bugs can be submitted through the web interface at http://rt.cpan.org/Dist/Display.html?Queue=POE-Component-Client-NNTP-Tail

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

• POE
• POE::Component::Client::NNTP

David A. Golden (DAGOLDEN)

Portions based on or inspired by code in POE::Component::SmokeBox::Uploads::NNTP by Chris Williams.

Copyright (c) 2008 by David A. Golden. All rights reserved.

Licensed under Apache License, Version 2.0 (the "License"). You may not use this file except in compliance with the License. A copy of the License was distributed with this file or you may obtain a copy of the License from http://www.apache.org/licenses/LICENSE-2.0

Files produced as output though the use of this software, shall not be considered Derivative Works, but shall be considered the original work of the Licensor.

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.