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Event::Join(3) User Contributed Perl Documentation Event::Join(3) NAME Event::Join - join multiple "events" into one SYNOPSIS use Event::Join; my $joiner = Event::Join->new( on_completion => sub { my $events = shift; say 'Child exited with status '. $events->{child_done}; }, events => [qw/stdout_closed child_done/], ); watch_fh $stdout, on_eof => sub { $joiner->send_event('stdout_closed') }; watch_child $pid, on_exit => sub { $joiner->send_event('child_done', $_[0]) }; start_main_loop; DESCRIPTION When writing event-based programs, you often want to wait for a number of events to occur, and then do something. This module allows you to do that without blocking. It simply acts as a receiver for a number of events, and then calls a callback when all events have occurred. Note that although I mainly use this for "real" event-based programming, the technique is rather versatile. A config file parser could be implemented like this: my $parsed_doc; my $parser_state = Event::Join->new( events => [qw/username password machine_name/], on_completion => sub { $parsed_doc = shift }, ); while(!$parsed_doc && (my $line = <$fh>)){ chomp $line; my ($k, $v) = split /:/, $line; $parser_state->send_event($k, $v); } say 'Username is '. $parsed_doc->{username}; METHODS new Create an instance. Needs to be passed "events", an arrayref of valid event names, and "on_completion", a coderef to call after all events have been received. This coderef is passed a hashref of events and their values, and will only ever be called once (or not at all, if the events never arrive). send_event( $event_name, [$event_value] ) Send an event. $event_name is required, and must be an event that was passed to the constructor. An exception will be thrown if the name is not valid. $event_value is optional; is is the value that goes into the hash to be passed to the callback. It can be true or false -- its value does not affect whether or not the completino callback is called. Finally, an exception is thrown if an event is sent more than once. event_sent( $event_name ) Returns true if the event has been sent, false otherwise. Note that the true value is not the value that was passed to "send_event", it is just an arbitrary non-false value. event_sender_for( $event_name ) Returns a coderef that sends $event_name when run. The first argument to the coderef will become the second argument to "send_event". PATCHES Is the module totally broken? Patch my repository at: http://github.com/jrockway/event-join AUTHOR Jonathan Rockway "<jrockway@cpan.org>" COPYRIGHT Copyright (c) 2009 Jonathan Rockway. This module is Free Software. You may distribute it under the same terms as Perl itself. perl v5.32.1 2011-02-25 Event::Join(3)
NAME | SYNOPSIS | DESCRIPTION | METHODS | PATCHES | AUTHOR | COPYRIGHT
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