NAME¶
AnyEvent::Callback - callback aggregator for AnyEvent watchers.
SYNOPSIS¶
use AnyEvent::Callback;
# usually watchers are looked as:
AE::something @args, sub { ... };
AE::something
@args,
sub { ... }, # result
sub { ... }; # error
use AnyEvent::Callback;
AE::something @args, CB { ... };
AE::something @args,
CB sub { ... }, # result
sub { ... }; # error
AE::something @args,
CB sub { ... }, # result
sub { ... }, # error
sub { ... }; # anyway callback
Callback hierarchy
my $cbchild = $cb->CB(sub { ... });
...
$cbchild->error('error'); # will call $cb->error('error');
Inside Your callback You can:
sub my_watcher {
my $cb = pop;
my @args = @_;
# ...
$cb->error( @error ); # error callback will be called
# or:
$cb->( $value ); # result callback will be called
}
Callbacks stack
my $cbs = CBS;
for (1 .. $n) {
AE::something @args, $cbs->cb;
}
$cbs->wait(sub {
for (@_) {
if ($_->is_error) { # handle one error
my @err = $_->errors; # or:
my $errstr = $_->errstr;
} else { # results
my @res = $_->results;
}
}
});
DESCRIPTION¶
The module allows You to create callback's hierarchy. Also the module groups
error and result callbacks into one object.
Also the module checks if one callback was called by watcher or not. If a
watcher doesn't call result or error callback, error callback will be called
automatically.
Also the module checks if a callback was called reentrant. In the case the
module will complain (using "carp" in Carp).
If a watcher touches error callback and if superior didn't define error
callback, the module will call error callback upwards hierarchy. Example:
AE::something @args, CB \&my_watcher, \&on_error;
sub on_error {
}
sub my_watcher {
my $cb = pop;
...
the_other_watcher $cb->CB( sub { # error callback wasn't defined
my $cb = pop;
...
yet_another_watcher1 $cb->CB( sub {
my $cb = pop;
...
$cb->( 123 ); # upwards callback
});
yet_another_watcher2 $cb->CB( sub {
my $cb = pop;
...
$cb->error( 456 ); # on_error will be called
});
});
}
METHODS¶
'CODE' (overloaded fake method)¶
$cb->( ... );
You can use the object as usually
CODEREF.
Creates new callback object that have binding on parent callback.
my $new_cb = $cb->CB(sub { ... }); # the cb doesn't catch errors
my $new_cb = CB(sub { ... }, sub { ... }); # the cb catches errors
my $new_cb = $cb->CB(sub { ... }, sub { ... }); # the same
error¶
Calls error callback. If the object has no registered error callbacks, parent
object's error callback will be called.
$cb->error('WTF?');
COPYRIGHT AND LICENCE¶
Copyright (C) 2012 by Dmitry E. Oboukhov
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.