| Catalyst-Runtime documentation | Contained in the Catalyst-Runtime distribution. |
Catalyst::Component::ContextClosure - Moose Role for components which need to close over the $ctx, without leaking
package MyApp::Controller::Foo;
use Moose;
use namespace::clean -except => 'meta';
BEGIN {
extends 'Catalyst::Controller';
with 'Catalyst::Component::ContextClosure';
}
sub some_action : Local {
my ($self, $ctx) = @_;
$ctx->stash(a_closure => $self->make_context_closure(sub {
my ($ctx) = @_;
$ctx->response->body('body set from closure');
}, $ctx));
}
A common problem with stashing a closure, that closes over the Catalyst context
(often called $ctx or $c), is the circular reference it creates, as the
closure holds onto a reference to context, and the context holds a reference to
the closure in its stash. This creates a memory leak, unless you always
carefully weaken the closures context reference.
This role provides a convenience method to create closures, that closes over
$ctx.
Returns a code reference, that will invoke $closure with a weakened
reference to $ctx. All other parameters to the returned code reference will
be passed along to $closure.
Florian Ragwitz <rafl@debian.org>
This library is free software. You can redistribute it and/or modify it under the same terms as Perl itself.
| Catalyst-Runtime documentation | Contained in the Catalyst-Runtime distribution. |
package Catalyst::Component::ContextClosure; use Moose::Role; use Scalar::Util 'weaken'; use namespace::autoclean; sub make_context_closure { my ($self, $closure, $ctx) = @_; weaken $ctx; return sub { $closure->($ctx, @_) }; } 1; __END__