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System Health and Templates

· 2 min read
Paulus Schoutsen
Paulus Schoutsen

In Home Assistant 0.118, there will be two changes that could impact your custom integration.

Removed deprecated helpers.template.extract_entities​

The previously deprecated extract_entities method from the Template helper has been removed (PR 42601). Instead of extracting entities and then manually listen for state changes, use the new async_track_template_result from the Event helper. It will dynamically make sure that every touched entity is tracked correctly.

from homeassistant.helpers.event import async_track_template_result, TrackTemplate

template = "{{ light.kitchen.state == 'on' }}"

async_track_template_result(
    hass,
    [TrackTemplate(template, None)],
    lambda event, updates: print(event, updates),
)

Improved System Health​

Starting with Home Assistant 0.118, we're deprecating the old way of providing system health information for your integration. Instead, create a system_health.py file in your integration (PR 42785).

Starting this release, you can also include health checks that take longer to resolve (PR 42831), like checking if the service is online. The results will be passed to the frontend when they are ready.

"""Provide info to system health."""
from homeassistant.components import system_health
from homeassistant.core import HomeAssistant, callback

from .const import DOMAIN


@callback
def async_register(
    hass: HomeAssistant, register: system_health.RegisterSystemHealth
) -> None:
    """Register system health callbacks."""
    register.async_register_info(system_health_info)


async def system_health_info(hass):
    """Get info for the info page."""
    client = hass.data[DOMAIN]

    return {
      "server_version": client.server_version,
      "can_reach_server": system_health.async_check_can_reach_url(
          hass, client.server_url
      )
    }