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Catalyst::Component::ContextClosure - Moose Role for components which need to

Catalyst::Component::ContextClosure(3pm) User Contributed Perl Documentation Catalyst::Component::ContextClosure(3pm)


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.


make_context_closure ($closure, $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.


CatalystX::LeakChecker This library is free software. You can redistribute it and/or modify it under the same terms as Perl itself.
2017-07-11 perl v5.24.1