Provide JavaScript example for persisting total price (#16889)

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>
Signed-off-by: Ciprian Pascu <contact@ciprianpascu.ro>
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Jacob Laursen 2024-06-20 23:48:20 +02:00 committed by Ciprian Pascu
parent 761a4206c4
commit 7b82dcb0ab

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@ -58,6 +58,8 @@ It will not impact channels, see [Electricity Tax](#electricity-tax) for further
| co2-emission-prognosis | Number:EmissionIntensity | Estimated prognosis for CO₂ emission following the day-ahead market in g/kWh |
| co2-emission-realtime | Number:EmissionIntensity | Near up-to-date history for CO₂ emission from electricity consumed in Denmark in g/kWh |
#### Total Price
_Please note:_ There is no channel providing the total price.
Instead, create a group item with `SUM` as aggregate function and add the individual price items as children.
This has the following advantages:
@ -69,6 +71,41 @@ This has the following advantages:
If you want electricity tax included in your total price, please add either `electricity-tax` or `reduced-electricity-tax` to the group - depending on which one applies.
See [Electricity Tax](#electricity-tax) for further information.
##### Time Series
Group items with aggregate functions are not automatically recalculated into the future when the time series for child items are updated.
Therefore, the `SUM` function mentioned above will only work for the current price.
Calculation of future total prices can be achieved with a rule (in this example file-based using Rule Builder):
:::: tabs
::: tab JavaScript
```javascript
rules.when()
.channel('energidataservice:service:energidataservice:electricity#event').triggered('DAY_AHEAD_AVAILABLE')
.then(event => {
var timeSeries = new items.TimeSeries('REPLACE');
var start = time.LocalDate.now().atStartOfDay().atZone(time.ZoneId.systemDefault());
var spotPrices = items.SpotPrice.persistence.getAllStatesBetween(start, start.plusDays(2));
for (var spotPrice of spotPrices) {
var totalPrice = spotPrice.quantityState
.add(items.GridTariff.persistence.persistedState(spotPrice.timestamp).quantityState)
.add(items.SystemTariff.persistence.persistedState(spotPrice.timestamp).quantityState)
.add(items.TransmissionGridTariff.persistence.persistedState(spotPrice.timestamp).quantityState)
.add(items.ElectricityTax.persistence.persistedState(spotPrice.timestamp).quantityState);
timeSeries.add(spotPrice.timestamp, totalPrice);
}
items.TotalPrice.persistence.persist(timeSeries);
})
.build("Calculate total price");
```
:::
::::
#### Currencies
There are some existing limitations related to currency support.