Callback Events

Skill: Callback and Event Roundtrip

When to Use

Use this skill when changing event callbacks or pane interactivity.

Core Workflow

1. Register callback handlers via register_event_handler() on the Python side.
2. Ensure frontend emits correct event payloads (event_type, target, and event-specific fields).
3. Route browser events through socket command forwarding (forward_to_vis).
4. Keep server forwarding logic from browser socket to Python source sockets intact.
5. Validate event names/fields against existing callback contracts.

Guardrails

• Callback handlers run in a background socket thread; avoid unsafe shared state writes.
• Do not rename event keys without coordinated client/server/docs updates.
• Preserve existing event types (Click, KeyPress, PropertyUpdate, Close, etc.).

Documentation

• Skill reference
• py/visdom/__init__.py
• py/visdom/server/handlers/socket_handlers.py
• js/api/ApiProvider.js
• js/EventSystem.js
• AGENTS.md
• CONTRIBUTING.md

Assets

• See assets/README.md and store templates/resources in assets/.

Tests

• Follow the default flow in references/TESTS.md.