✨ New Features & 🐛 Bug Fixes

✨ What's New

🧮 Computed values for Attribute Data Sources — data_value_expression + data_vars

data_attribute could already read a value straight out of an attribute array. Now you can compute it. Set data_value_expression and the card evaluates a small arithmetic formula for every element — with the element's own fields in scope, plus any other entities you pull in through data_vars.

- entity: sensor.tibber_hourly_cost
  graph_type: bar
  data_attribute: nodes
  data_time_field: from
  data_time_unit: iso
  data_value_expression: "(unitPrice - unitPriceVAT) * 100 * consumption * (1 + mwst)"
  data_vars:
    mwst: input_number.vat_rate

• Combine several element fields and fold in fees, tax rates or tariffs from other entities — the kind of thing that used to need an ApexCharts data_generator or a helper template sensor.
• data_vars entities are watched: change one and the chart re-evaluates live.
• Operators + - * / %, parentheses, and the functions min, max, abs, round, floor, ceil, sqrt, pow.
• It is not JavaScript — no property access, no globals, no arbitrary calls — so nothing unsafe runs in your dashboard. An empty or invalid expression simply falls back to data_value_field.
• Editor support: per-entity → Data tab → Attribute Data Source → Value Expression and Data Vars.

Stacked layers (e.g. consumption + fixed fees), per-point math, several series off the same array — all from config. See the README → Attribute Data Source → Computed Values.

📊 Per-group tooltip totals — tooltip_stacked_total

On a stacked chart with multiple stack_groups, the tooltip can now show a total per group — labelled with the group name (e.g. "energy Total", "cost Total") — instead of only one combined number.

stacked: true
tooltip_stacked_total: true   # default

It's independent of the existing Tooltip Total: with both on, the tooltip lists the per-group totals and the grand Total of all entities. On by default; turn it off to keep just the grand Total. The per-group rows appear only when there are 2+ groups, and ungrouped entities roll into the grand Total. Editor: Tooltip → Stacked Group Totals.

🐛 Fixes

• Forecast/price data no longer disappears while the card is open. Attribute-based future series (EPEX, Nord Pool, Tibber, weather, solar) kept their window on the first paint but collapsed back to now after ~30 s of live updates. The future portion is now preserved on every refresh. (#229, #226, #225)
• Stable bar values during live updates. With aggregate_func: change / diff / delta (e.g. monthly consumption from an ever-increasing counter), bar heights could jump or drift while the card was on screen. The live path now re-aggregates through the same code as the full render. (#228)
• Calendar mode — correct cell values for change / diff / delta. The heat-map cell showed the daily average while the tooltip showed the right per-day change; the cell now matches the tooltip. (#230)
• Range band — clean lower edge under Bézier smoothing. With show_range_band plus smoothing, the bottom edge of the band rendered distorted / "blurry". It now mirrors the top edge. (#231)

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After updating, hard-refresh your browser (or bump the ?v= on the resource URL) so the new version loads.

If this card is useful to you, a ⭐ on the repo genuinely helps.