feat(sdk): add event bus for inter-addon communication (#382) #398

forbes · 2026-03-04T15:46:05Z

forbes commented

2026-03-04 15:46:05 +00:00

Closes #382

Summary

Adds a lightweight publish-subscribe event bus so addons can communicate without importing each other directly.

New API

import kindred_sdk as sdk

def handler(data):
    print(f"Document locked: {data}")

sdk.on("silo.document_locked", handler)
sdk.emit("silo.document_locked", {"doc_id": "abc", "user": "forbes"})
sdk.off("silo.document_locked", handler)

sdk.on(event, handler) — subscribe (deduplicates)
sdk.off(event, handler) — unsubscribe (silent no-op if not found)
sdk.emit(event, data) — publish dict payload to all subscribers

Design

Pure Python, no kcsdk C++ dependency
Synchronous dispatch on Qt main thread
Snapshot iteration — safe under re-entrancy (handler emits, self-unsubscribe, handler-adds-handler)
Handler exceptions logged via PrintWarning, remaining handlers still fire
Follows registry.py / statusbar.py patterns: input validation, defensive defaults, FreeCAD.Console logging

Changes

mods/sdk/kindred_sdk/events.py (new) — event bus module
mods/sdk/kindred_sdk/__init__.py — import and export emit, on, off

Closes #382 ## Summary Adds a lightweight publish-subscribe event bus so addons can communicate without importing each other directly. ## New API ```python import kindred_sdk as sdk def handler(data): print(f"Document locked: {data}") sdk.on("silo.document_locked", handler) sdk.emit("silo.document_locked", {"doc_id": "abc", "user": "forbes"}) sdk.off("silo.document_locked", handler) ``` - `sdk.on(event, handler)` — subscribe (deduplicates) - `sdk.off(event, handler)` — unsubscribe (silent no-op if not found) - `sdk.emit(event, data)` — publish dict payload to all subscribers ## Design - Pure Python, no kcsdk C++ dependency - Synchronous dispatch on Qt main thread - Snapshot iteration — safe under re-entrancy (handler emits, self-unsubscribe, handler-adds-handler) - Handler exceptions logged via `PrintWarning`, remaining handlers still fire - Follows `registry.py` / `statusbar.py` patterns: input validation, defensive defaults, `FreeCAD.Console` logging ## Changes - **`mods/sdk/kindred_sdk/events.py`** (new) — event bus module - **`mods/sdk/kindred_sdk/__init__.py`** — import and export `emit`, `on`, `off`

forbes added 1 commit 2026-03-04 15:46:07 +00:00

feat(sdk): add event bus for inter-addon communication (#382 )

Build and Test / build (pull_request) Successful in 25m4s

Details

7567054882

New module kindred_sdk/events.py provides lightweight publish-subscribe
so addons can signal each other without direct imports.

New public API:
- sdk.on(event, handler) — subscribe to a named event
- sdk.off(event, handler) — unsubscribe
- sdk.emit(event, data) — publish event with dict payload

Pure Python, synchronous dispatch, snapshot-safe iteration.
Handlers that raise are logged and skipped without breaking the chain.

forbes force-pushed feat/sdk-event-bus from 7567054882 to 54b926a925

2026-03-04 15:47:51 +00:00

Compare

forbes merged commit 9f71d0efe6 into main

2026-03-04 15:48:19 +00:00

forbes deleted branch feat/sdk-event-bus

2026-03-04 15:48:19 +00:00

forbes referenced this issue from a commit

2026-03-04 15:48:20 +00:00

Merge pull request 'feat(sdk): add event bus for inter-addon communication (#382)' (#398) from feat/sdk-event-bus into main

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Reference: kindred/create#398