NAME
POE::Component::DirWatch - POE directory watcher
SYNOPSIS
use POE::Component::DirWatch;
my $watcher = POE::Component::DirWatch->new
(
alias => 'dirwatch',
directory => '/some_dir',
filter => sub { $_[0]->is_file ? $_[0] =~ /\.gz$/ : 1 },
dir_callback => sub{ ... },
file_callback => sub{ ... },
interval => 1,
);
$poe_kernel->run;DESCRIPTION
POE::Component::DirWatch watches a directory for files or directories. Upon finding either it will invoke a user-supplied callback function depending on whether the item is a file or directory.
ASYNCHRONOUS IO SUPPORT
This object supports asynchronous IO access using IO::AIO. At load time, the class will detect whether IO::AIO is present in the host system and, if it is present, apply the POE::Component::DirWatch::Role::AIO role to the current class, adding the aio attribute, the <aio_callback> event, and replacing _poll with an asynchronous version. If you do not wish to use AIO you can specify so with he no_aio flag like this:
use POE::Component::DirWatch (no_aio => 1);ATTRIBUTES
alias
Read only alias for the DirWatch session. Defaults to dirwatch if not specified. You can NOT rename a session at runtime.
directory
Read-write, required. A Path::Class::Dir object for the directory watched. Automatically coerces strings into Path::Class::Dir objects.
interval
Required read-write integer representing interval between the end of a poll event and the scheduled start of the next. Defaults to 1.
file_callback
Optional read-write code reference to call when a file is found. The code reference will passed a single argument, a Path::Class::File object representing the file found. It usually makes most sense to process the file and remove it from the directory to avoid duplicate processing
dir_callback
Optional read-write code reference to call when a directory is found. The code reference will passed a single argument, a Path::Class::Dir object representing the directory found.
filter
An optional read-write code reference that, if present, will be called for each item in the watched directory. The code reference will passed a single argument, a Path::Class::File or Path::Class::Dir object representing the file/dir found. The code should return true if the callback should be called and false if the file should be ignored.
next_poll
The ID of the alarm for the next scheduled poll, if any. Has clearer and predicate methods named clear_next_poll and has_next_poll. Please note that clearing the next_poll just clears the next poll id, it does not remove the alarm, please use pause for that.
OBJECT METHODS
new( \%attrs)
See SYNOPSIS and ATTRIBUTES.session
Returns a reference to the actual POE session. Please avoid this unless you are subclassing. Even then it is recommended that it is always used as $watcher->session->method because copying the object reference around could create a problem with lingering references.
pause [$until]
Synchronous call to _pause. This just posts an immediate _pause event to the kernel.
resume [$when]
Synchronous call to _resume. This just posts an immediate _resume event to the kernel.
shutdown
Convenience method that posts a FIFO shutdown event.
meta
See Moose;
EVENT HANDLING METHODS
These methods are not part of the public interface of this class, and expect to be called from whithin POE with the standard positional arguments. Use them at your own risk.
_start
Runs when $poe_kernel->run is called to set the session's alias and schedule the first poll event.
_poll
Triggered by the poll event this is the re-occurring action. _poll will use get a list of all items in the directory and call the appropriate callback.
_file_callback
Will execute the file_callback code reference, if any.
_pause [$until]
Triggered by the _pause event this method will remove the alarm scheduling the next directory poll. It takes an optional argument of $until, which dictates when the polling should begin again. If $until is an integer smaller than the result of time() it will treat $until as the number of seconds to wait before polling. If $until is an integer larger than the result of time() it will treat $until as an epoch timestamp.
#these two are the same thing
$watcher->pause( time() + 60);
$watcher->pause( 60 );
#this is one also the same
$watcher->pause;
$watcher->resume( 60 );_resume [$when]
Triggered by the _resume event this method will remove the alarm scheduling the next directory poll (if any) and schedule a new poll alarm. It takes an optional argument of $when, which dictates when the polling should begin again. If $when is an integer smaller than the result of time() it will treat $until as the number of seconds to wait before polling. If $until is an integer larger than the result of time() it will treat $when as an epoch timestamp and schedule the poll alarm accordingly. If not specified, the alarm will be scheduled with a delay of zero.
_shutdown
Delete the heap, remove the alias we are using and remove all set alarms.
BUILD
Constructor. create()s a POE::Session.
TODO
SEE ALSO
POE::Session, POE::Component, Moose, POE,
The SVN repository for this project can be found in it's Google Code project page - http://code.google.com/p/poe-component-dirwatch-object/
AUTHOR
Guillermo Roditi, <groditi@cpan.org>
BUGS
Please report any bugs or feature requests to bug-poe-component-dirwatch at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=POE-Component-DirWatch. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
ACKNOWLEDGEMENTS
COPYRIGHT
Copyright 2006-2008 Guillermo Roditi. All Rights Reserved. This is free software; you may redistribute it and/or modify it under the same terms as Perl itself.