X, Y mapping from sensor's attribute (date, value - fixed structure)

[kppr0]

Hello,

I have following data:

The structure is fixed [date, value] and data are stored in sensor's attribute.

I tried this x, y $ex but doesn't work:

entities:
  - entity: sensor.current_spot_electricity_price
    x:
      - "$ex hass.states['sensor.current_spot_electricity_price'].attributes.map(([date, value]) => new Date(date))"
    "y":
      - "$ex hass.states['sensor.current_spot_electricity_price'].attributes.map(([date, value]) => value)"

If helps, working apexcharts code is:

data_generator: |
  return Object.entries(entity.attributes).map(([date, value], index) => {
    return [new Date(date).getTime() + (30 * 60 * 1000), value];
  });

Please, do you have any ideas?

[Tom-Bom-badil]

Just came across similar data of a Viessmann water heating tank, where I even had to create proper timestamps before displaying it in plotly.

Raw data were looking like ["01": 2.5, "02": 1.7, "03": 0.3,...], translating to [{"date": "2025-07-01T23:59:59", "value": 2.5}, ​...}] in the attribute of a template sensor I created for pre-compiling before handing over the data to the card. All other attempts I tried (even with rather complex $fn's) didn't work for different reasons (pretty sure most of them are sitting here in front of the display). The final plotly code is rather short:

entities:
  - entity: sensor.vitocal_domestic_hot_water_stats
    attribute: months_combined
    name: Daily consumption
    type: bar
    x: $fn ({meta}) => meta.months_combined.map(item => new Date(item.date))
    "y": $fn ({meta}) => meta.months_combined.map(item => item.value)

Not sure if this is the most efficient way how to do it (likely not), but it's working pretty well. Full story including instructions on how to setup a dummy plot page with simulated data here, if you don't mind translating from German. Your situation should be easier to handle, as the date is already there in the right format, so the Jinja of the template sensor should be way shorter.

Hope this helps pointing you to the right direction, good luck!

/tom

[kppr0]

Hallo Tom, Deutsch ist wunderbar :-)

This is definitely the right way, but I have problem with reading attribute field of this sensor.

In Developer Tools => Templates I tried:

{{ state_attr('sensor.current_spot_electricity_price', 'spot_combined') }}

but the result is "null":

"spot_combined" is my label, there is no such label in the attribute field:

Please don't you know what I'm doing wrong?