Creating a template sensor to count ZHA updates

Since ZHA supports Zigbee updates since today, I was trying to create a template sensor that counts how many updates are due for my Zigbee devices. I tried to use this as a template:

{{ states.update | integration_entities('Zigbee Home Automation') |  selectattr('state', '==', 'on') | list | count }}

However, the integration_entities piece is not working. As per the documentation it should give me a list of all entities in ZHA, however the template sensor returns “not available”. Also tried lower case, using “ZHA”, “zha”… I also tried another way that I found in a forum:

{{ states.update | selectattr('attributes.integration', 'in', ['zigbee']) |  selectattr('state', '==', 'on') | list | count }}

However the sensor returns 0 (I removed the state filter for testing - should count the number of update-entities in the ZHA integration).

Does anyone have an idea how to fix this?

EDIT: Experimented a little more, the integration_entities part seems to work if I put it as the first item in the template:

{{ integration_entities('zha') | list | count }}

Buuuuut… once I add the filter that selects only the update entities… it doesn’t work anymore and returns 0:

{{ integration_entities('zha') | selectattr('domain', 'contains', 'update') | list | count }}

Also tried another way since zha is adding the keyword “firmware” to all those entities:

{{ integration_entities('zha') | selectattr('unique_id', 'contains', 'firmware') | list | count }}

… returns 0 as well.

{{ integration_entities('zha') | select("match", "^update\..*$") | map("states") | select("equalto", "on") | list | count  }}

It may not be the most efficient way, but seems to do the trick