67 lines
1.9 KiB
Markdown
67 lines
1.9 KiB
Markdown
---
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author: Josef Zweck
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authorURL: https://github.com/zweckj
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title: Set up your DataUpdateCoordinator with a setup method
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---
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In Home Assistant 2024.8, we are introducing the `_async_setup` method for the data update coordinator.
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This method allows you to run asynchronous code to prepare your `DataUpdateCoordinator` instance
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or to load data that only needs to be loaded once.
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You can override `_async_setup` in your coordinator, and it will be automatically
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called during `coordinator.async_config_entry_first_refresh()`.
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It offers the same error handling as `_async_update_data` and will handle `ConfigEntryError`
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and `ConfigEntryAuthFailed` accordingly.
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## Example
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```python
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class MyUpdateCoordinator(DataUpdateCoordinator[MyDataType]):
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prereq_data: SomeData
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def __init__(
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self,
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hass: HomeAssistant,
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) -> None:
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"""Initialize coordinator."""
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super().__init__(hass, _LOGGER, name=DOMAIN, update_interval=SCAN_INTERVAL)
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self.my_api = MyApi()
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async def _async_setup(self) -> None:
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"""Do initialization logic."""
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self.prereq_data = await self.my_api.get_initial_data()
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async def _async_update_data(self) -> MyDataType:
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"""Do the usual update"""
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return await self.my_api.update(self.prereq_data)
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```
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## Avoiding checks for initialization status
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This change allows you to refactor code that loaded the initial data in
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the `_async_update_data` method by checking an initialization variable, like
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```python
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async def _async_update_data(self) -> ...:
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if not self.something:
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self.something = self.client.fetch()
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return self.client.fetch_data()
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```
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into
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```python
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async def _async_setup(self) -> None:
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self.something = self.client.fetch()
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async def _async_update_data(self) -> ...:
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return self.client.fetch_data()
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```
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## More information
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Read more about this in the [documentation](https://developers.home-assistant.io/docs/integration_fetching_data/)
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