ha-integration-patterns

Home Assistant 自定义集成模式和架构决策。在为 Home Assistant 构建 HACS 集成、自定义组件或 API 桥时使用。涵盖服务响应数据、HTTP 视图、存储 API 和集成架构。

## 概述（中文）

Home Assistant 自定义集成模式和架构决策。在为 Home Assistant 构建 HACS 集成、自定义组件或 API 桥时使用。涵盖服务响应数据、HTTP 视图、存储 API 和集成架构。

## 原文

# Home Assistant Integration Patterns

## Service Response Data Pattern

### The Problem
By default, HA services are "fire-and-forget" and return empty arrays `[]`.

### The Solution (HA 2023.7+)
Register service with `supports_response`:

```python
from homeassistant.helpers.service import SupportsResponse

hass.services.async_register(
    domain, 
    "get_full_config", 
    handle_get_full_config,
    schema=GET_CONFIG_SCHEMA,
    supports_response=SupportsResponse.ONLY,  # ← KEY PARAMETER
)
```

Call with `?return_response` flag:
```bash
curl -X POST "$HA_URL/api/services/your_domain/get_full_config?return_response"
```

### Response Handler
```python
async def handle_get_full_config(hass: HomeAssistant, call: ServiceCall):
    """Handle the service call and return data."""
    # ... your logic ...
    return {"entities": entity_data, "automations": automation_data}
```

---

## HTTP View vs Service: When to Use Each

| Use Case | Use | Don't Use |
|----------|-----|-----------|
| Return complex data | HTTP View | Service (without response support) |
| Fire-and-forget actions | Service | HTTP View |
| Trigger automations | Service | HTTP View |
| Query state/config | HTTP View | Internal storage APIs |

### HTTP View Pattern
For data retrieval APIs:

```python
from homeassistant.components.http import HomeAssistantView

class OpenClawConfigView(HomeAssistantView):
    """HTTP view for retrieving config."""
    url = "/api/openclaw/config"
    name = "api:openclaw:config"
    requires_auth = True

    async def get(self, request):
        hass = request.app["hass"]
        config = await get_config_data(hass)
        return json_response(config)

# Register in async_setup:
hass.http.register_view(OpenClawConfigView())
```

---

## Critical: Avoid Internal APIs

**Never use underscore-prefixed APIs** — they're private and change between versions.

❌ **Wrong:**
```python
storage_collection = hass.data["_storage_collection"]
```

✅ **Right:**
```python
# Use public APIs only
from homeassistant.helpers.storage import Store
store = Store(hass, STORAGE_VERSION, STORAGE_KEY)
```

---

## Storage Patterns

### For Small Data (Settings, Cache)
```python
from homeassistant.helpers.storage import Store

STORAGE_KEY = "your_domain.storage"
STORAGE_VERSION = 1

store = Store(hass, STORAGE_VERSION, STORAGE_KEY)

# Save
data = {"entities": modified_entities}
await store.async_save(data)

# Load
data = await store.async_load()
```

### For Large Data (History, Logs)
Use external database or file storage, not HA storage helpers.

---

## Breaking Changes to Watch

| Change | Version | Migration |
|--------|---------|-----------|
| Conversation agents | 2025.x+ | Use `async_process` directly |
| Service response data | 2023.7+ | Add `supports_response` param |
| Config entry migration | 2022.x+ | Use `async_migrate_entry` |

**Always check:** https://www.home-assistant.io/blog/ for your target version range.

---

## HACS Integration Structure

```
custom_components/your_domain/
├── __init__.py          # async_setup_entry
├── config_flow.py       # UI configuration
├── manifest.json        # Dependencies, version
├── services.yaml        # Service definitions
└── storage_services.py  # Your storage logic
```

### Minimal manifest.json
```json
{
  "domain": "your_domain",
  "name": "Your Integration",
  "codeowners": ["@yourusername"],
  "config_flow": true,
  "dependencies": [],
  "requirements": [],
  "version": "1.0.0"
}
```

---

## Testing Checklist

- [ ] Service calls return expected data (with `?return_response`)
- [ ] HTTP views accessible with auth token
- [ ] No underscore-prefixed API usage
- [ ] Storage persists across restarts
- [ ] Config flow creates config entry
- [ ] Error handling returns meaningful messages

---

## Documentation Resources

- Integration basics: `developers.home-assistant.io/docs/creating_integration_index`
- Service calls: `developers.home-assistant.io/docs/dev_101_services`
- HTTP views: `developers.home-assistant.io/docs/api/webserver`
- Breaking changes: `home-assistant.io/blog/` (filter by version)
- HACS guidelines: `hacs.xyz/docs/publish/start`

---

## Lesson Learned

From HA-OpenClaw Bridge attempt:

> *"80% of our issues were discoverable with 30-60 minutes of upfront docs reading. We jumped straight to coding based on assumptions rather than reading how HA actually works."*

Use `skills/pre-coding-research/` methodology before starting.