Fix async state scoping for submodules (#2866)

[raza-khan0108]

What type of PR is this? (Check all that apply)

• 🛠 Refactor
• ✨ Feature
• 🐛 Bug Fix
• ⚡ Optimization
• 📝 Documentation Update

Description

This PR resolves an issue where _AsyncState failed to correctly resolve the module context when accessing or modifying variables within a submodule. By capturing the module context using the caller's stack frame in __getattr__ and __setattr__ (via inspect.stack()[1]), state variables accessed during async callbacks are now correctly resolved in the proper submodule context instead of erroneously falling back to __main__.

Related Tickets & Documents

• Closes [🐛 BUG] Async callback submodule scoping issue #2866

How to reproduce the issue

Set up an application with a submodule handling an async callback, where state variables are updated.

1. Create a main file (main.py) routing to a home_page imported from a submodule (pages/home.py).
2. Inside pages/home.py, define an async callback (e.g. async def count_to_10(state): state.counter = 10) hooked up to a button.
3. Click the button. Previously, this would trigger Variable 'counter' is not available in the '__main__' module or AttributeError. It now successfully resolves the variable inside the pages.home context.

(See #2866 for the full reproduction code).

Backporting

This change should be backported to:

• 3.0
• 3.1
• 4.0
• develop

Checklist

We encourage keeping the code coverage percentage at 80% or above.

• ✅ This solution meets the acceptance criteria of the related issue.
• 📝 The related issue checklist is completed.
• 🧪 This PR includes unit tests for the developed code.
  If not, explain why:
• 🔄 End-to-End tests have been added or updated.
  If not, explain why: A unit test accurately captures and isolates the _AsyncState module scoping bug, rendering a full end-to-end test unnecessary for this fix.
• 📚 The documentation has been updated, or a dedicated issue has been created.
  If not, explain why: This is an internal framework fix and introduces no public API or syntax changes for users.
• 📌 The release notes have been updated.
  If not, explain why: Can be handled internally during the release preparation if necessary.

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