I have a couple places where I need the N latest values of a sensor.
However, in very recent HA versions I noticed that self-referencing templates suddenly seem to be evaluated twice. For example:
template:
- unique_id: my_meter
trigger:
- platform: webhook
webhook_id: my-webhook-id
local_only: true
sensor:
- name: "My meter: power history"
unique_id: my_meter_power_history
state: "{{ ([ now().timestamp()|int, trigger.json['mykey']|float ] + this.state.split('|'))[:8]|join('|') }}"
With this, I would expect the state to be (with added spaces for readability):
timestampN | valueN | timestampN-1 | valueN-1 | timestampN-2 | valueN-2 | timestampN-3 | valueN-3
But instead I’m getting:
timestampN | valueN | timestampN | valueN | timestampN-1 | valueN-1 | timestampN-1 | valueN-1
From what I see, the state is evaluated twice because of the self-reference.
In the states database, I also see each state listed twice (within a few milliseconds).
It appears that the state is evaluated twice with the same context (eg: trigger.id, trigger.json are the same) but haven’t looked further.
Of course the Webhook is only called once. And as soon as I remove the self-reference, the double evaluation vanishes.
Anyone noticed this? This seems to be specific to recent HA versions.
And of course the inevitable question: how can I self-reference the previous value of a template, without it being evaluated a 2nd time afterwards?
