如何创建仅在一个请求期间全局的“全局”范围变量？

Question

When a request hits my dancer2 app I want to set up an object that is accessible by all packages involved in handling this request.

How can I make sure that this object has a scope only within this individual request and is not accessible by other requests?

Specifically this object should be filled with messages of all kinds (errors, warnings, debug messages, etc.) as execution travels through my libraries.

Obviously, those messages are request-specific and I am afraid that naively declaring a global reference to this message object is exposing it to all requests hitting the app.

I was thinking about creating an instance of this message class in the router and then passing a reference to it throughout all methods involved in handling this request.

My gut feeling tells me that I am missing something fundamentally here architecture-wise regarding dancer2, so I decided to ask you. It's my first post here, by the way, so I apologize for any shortcomings my question may have.

Answer 1

It looks to me like you could use a var to hold your object.

See https://metacpan.org/pod/distribution/Dancer2/lib/Dancer2/Manual.pod#var

If you need it to be accessible even from methods that aren't aware of Dancer, you could use a var and also store your object in a global variable using a weak reference.