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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__
=head1 NAME
Catalyst::Component::ContextClosure - Moose Role for components which need to close over the $ctx, without leaking
=head1 SYNOPSIS
package MyApp::Controller::Foo;
use Moose;
use namespace::clean -except => 'meta';
BEGIN {
extends 'Catalyst::Controller';
with 'Catalyst::Component::ContextClosure';
}
sub some_action : Local {
my ($self, $ctx) = @_;
$ctx->stash(a_closure => $self->make_context_closure(sub {
my ($ctx) = @_;
$ctx->response->body('body set from closure');
}, $ctx));
}
=head1 DESCRIPTION
A common problem with stashing a closure, that closes over the Catalyst context
(often called C<$ctx> or C<$c>), is the circular reference it creates, as the
closure holds onto a reference to context, and the context holds a reference to
the closure in its stash. This creates a memory leak, unless you always
carefully weaken the closures context reference.
This role provides a convenience method to create closures, that closes over
C<$ctx>.
=head1 METHODS
=head2 make_context_closure ($closure, $ctx)
Returns a code reference, that will invoke C<$closure> with a weakened
reference to C<$ctx>. All other parameters to the returned code reference will
be passed along to C<$closure>.
=head1 SEE ALSO
L<Catalyst::Component>
L<Catalyst::Controller>
L<CatalystX::LeakChecker>
=head1 AUTHOR
Florian Ragwitz E<lt>rafl@debian.orgE<gt>
=head1 COPYRIGHT
This library is free software. You can redistribute it and/or modify it under
the same terms as Perl itself.
=cut
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