Can't change language

Alessandro.fardin · June 25, 2025, 11:47am

Hi all.

I’m moving the first steps with OpenEms.

I’ve successfully built both the OpenEms edge and opeEns UI V. 2026.6.0-SNAPSHOT
I’ve deployed both on my linux Embedded device.
All run correctly, I’m running the simulation described on the getting getting started guide.

I’m facing a problem, I can’t set the UI in English or other languages different from the default (de)

I’m logged in with the admin user, when I try to change the language I’ve the error see the attached image

Could you help me ?
thank you in advance

sjjh · June 25, 2025, 8:10pm

Sorry, no solution here, just the additional info, that for me it’s the same. I’m using the provided docker images for edge and UI.

s_h · June 25, 2025, 8:28pm

Same here. But did you notice this remark?

The language can not be changed permanently in the local online-monitoring for technical reasons.

Maybe this only works on the backend?

Sn0w3y · June 26, 2025, 6:55am

yes. exactly this is the case.

Alessandro.fardin · June 26, 2025, 8:49am

So we have to configure the backend (in my case the edge) by modifying the openems edge code ?
Are there any guide about changing openems language ?

sjjh · June 26, 2025, 9:39am

The Backend and the Edge are two different software packages. In my understanding you would need to install the Backend in addition to the Edge.

Maybe this is what you are looking for:

How about adding this requirement to the error message? Suggestion: “Change failed Endpoint with method “updateUserLanguage” is not defined! Please ensure, that the Backend is installed and configured correctly.”

Sn0w3y · June 26, 2025, 1:58pm

You could just set the default language in the UI code to your language.

Alessandro.fardin · June 26, 2025, 2:31pm

The BackEnd is the cloud component, but I’d like to run tests without relying on it.
I’m currently using the Edge module and the UI directly on the embedded device.
However, it seems that the language settings require the BackEnd module to function properly.
As for our demo we need to have english.

I try to modify the UI code, but without success:

ui/src/app/shared/type/language.ts:
public static readonly DEFAULT = Language.EN;

ui/src/app/app.module.ts
{ provide: LOCALE_ID, useFactory: () => (Language.EN ?? Language.EN ?? Language.EN).key },

ui/src/themes/openems/environments/theme.ts
defaultLanguage: "en",

copied en.json to ui/src/assets/i18n/de.json

none of these worked:
UI run always in german

Sn0w3y · June 27, 2025, 9:49am

If you did this and it did not change - seems more like a Caching Issue.

sjjh · June 29, 2025, 9:30am

I did find two files out of which the error message is combined, thus the change is probably not as trivial as I was hoping:

github.com/OpenEMS/openems

ui/src/assets/i18n/en.json

0f7119c2c


      
          "active": "Active",
          "actualPower": "EV charging power",
          "ALL": "All",
          "CURRENT_STATUS": "Current status",
          "apply": "Apply",
          "autarchy": "Autarchy",
          "automatic": "Automatic",
          "cancel": "Cancel",
          "capacity": "Capacity",
          "changeAccepted": "Change accepted",
          "changeFailed": "Change failed",
          "chargeDischarge": "Charge/Discharge",
          "componentCount": "Number of components",
          "componentInactive": "Component is not active!",
          "connectionLost": "Connection lost. Trying to reconnect.",
          "consumption": "Consumption",
          "cumulative": "Cumulative Values",
          "currentName": "current name",
          "currentValue": "current value",
          "dateFormat": "yyyy-MM-dd",
          "digitalInputs": "Digital Inputs",

github.com/OpenEMS/openems

io.openems.edge.common/src/io/openems/edge/common/jsonapi/JsonApiBuilder.java

0f7119c2c


      
          			Call<JsonrpcRequest, JsonrpcResponse> call //
          	) {
          		final var endpoint = this.endpoints.get(call.getRequest().getMethod());
          		trace.add(new JsonHandlerTrace(call.getRequest().getMethod(), endpoint != null));
          		call.put(DEPTH, depth + 1);
          		call.put(TRACE, trace);
          
          		if (endpoint == null) {
          			// TODO later for notifications there should not be a response
          			call.setResponse(new JsonrpcResponseError(call.getRequest().getId(),
          					"Endpoint with method \"" + call.getRequest().getMethod() + "\" is not defined!"));
          			return;
          		}
          
          		// handle request
          		endpoint.handle(this, call);
          	}
          
          }

As I didn’t receive any feedback on this, I’ll currently not continue on this on my own.

stefan.feilmeier · July 10, 2025, 5:18pm

The reason why this is not possible with Edge is, that currently there is no handling for UpdateUserLanguageRequest in Edge. It’s not currently on our roadmap to implement this, but it would not be too hard to do it… The value should maybe be stored in the UserService configuration: openems/io.openems.edge.core/src/io/openems/edge/core/user/Config.java at develop · OpenEMS/openems · GitHub

Is anybody interested to implement this?