NAME
Async::Chain - The right way to convert nested callback in plain struct
or just the syntax sugar for guy who unlike deep indent.
VERSION
Version 0.04
SYNOPSIS
Every subroutine in the chain receive callable object as first argument
followed by arguments of prevision object call. You can break chain in
every sub, just do not call $next.
You can skip some subroutins using skip or jump method.
use Async::Chain;
# with chain call
chain
sub {
my next = next;
AnyEvent::HTTP::http_get('
http://perldoc.perl.org/', sub { $next->(@_)});
},
sub {
my next = next;
...
$tnt->lua('box.insert', ..., sub { $next->(@_) })
},
sub {
my next = next;
...
$next->();
},
sub {
...
log(...);
};
# with constructor
my $next = Async::Chain->new(
sub {
my next = next;
AnyEvent::HTTP::http_get('
http://perldoc.perl.org/', sub { $next->(@_)});
},
sub {
my next = next;
...
$tnt->lua('box.insert', ..., sub { $next->(@_) })
},
sub {
my next = next;
...
$next->();
},
finalize => sub {
...
log(...);
};
);
if (...) {
$next->jump('finalize');
}
$next->();
RATIONALE
A asynchronous code often have deep nested callbacks, therefore it is
tangled and hard to change. This module help to convert code like
following to some more readable form.
without chain:
sub f {
...
some_anync_call @args, cb => sub {
...
some_other_anync_call @args, cb => sub {
...
...
...
yet_another_anync_call @args, cb => sub {
...
}
}
}
}
using chain:
chain
sub {
my next = next;
...
some_anync_call @args, cb => sub { $next->(@arg) }
},
sub {
my next = next;
...
some_other_anync_call @args, cb => sub { $next->(@arg) }
},
sub {
my next = next;
...
},
...
sub {
...
yet_another_anync_call @args, cb => sub { $next->(@arg) }
},
sub {
...
};
SUBROUTINES/METHODS
new
The Asyn::Chain object constructor. Arguments are list of subroutine
optionaly leaded by mark.
chain
Only one exported subroutine. Create and call Anync::Chain object.
Return empty list.
skip
Skip one or more subroutine. Skipe one if no argument given. Return
Anync::Chain object.
jump
Skip subroutines for first entry of named mark. Return Anync::Chain
object.
hitch
Move named link to beginning of the chain. When link with given name
not exists or first in chain, method has no effect. Return Anync::Chain
object.
AUTHOR
Anton Reznikov, "<anton.n.reznikov at gmail.com>"
BUGS
Please report any bugs or feature requests, or through GitHub web
interface at <
https://github.com/17e/Async-Chain>.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc Async::Chain
ACKNOWLEDGEMENTS
Mons Anderson - The original idia of chain and it first implementation.
LICENSE AND COPYRIGHT
Copyright 2014 Anton Reznikov.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; version 2 dated June, 1991 or at your option
any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
A copy of the GNU General Public License is available in the source
tree; if not, write to the Free Software Foundation, Inc., 51 Franklin
Street, Fifth Floor, Boston, MA 02110-1301 USA
perl v5.10.1 2014-06-19 Async::Chain(3)
