Custom Translation in Data Post-Processing

This recipe shows how to use custom translation keys in a data post-processing function of an Entities table widget. The i18n keys returned by the function are resolved to the user’s interface language.

Prerequisites

A ThingsBoard PE instance with custom translation configured
A device sending temperature telemetry

Add translation keys

Navigate to White labeling > Custom translation and add the following keys for the target language (e.g., German):

Term key	English	German	Description
`custom.my-dashboard.title`	My Dashboard	Mein Dashboard	Dashboard title
`custom.my-widget.telemetry-key.temperature`	Temperature	Temperatur	Telemetry key label
`custom.my-widget.telemetry-value.range`	Value range	Wertebereich	Column header
`custom.my-widget.telemetry-value.low-temperature`	Low temperature	Niedrigtemperatur	Low temperature
`custom.my-widget.telemetry-value.high-temperature`	High temperature	Hochtemperatur	High temperature
`custom.my-widget.telemetry-value.normal-temperature`	Normal temperature	Normaltemperatur	Normal temperature

Open the dashboard in edit mode and click Add widget.
Select the Entities table widget from the Tables widgets bundle.
Specify the device as the data source. Add three columns:
- Name (default entity name column)
- Temperature — telemetry key temperature, label: {i18n:custom.my-widget.telemetry-key.temperature}
- Temperature range — telemetry key temperature, label: {i18n:custom.my-widget.telemetry-value.range}

Configure the post-processing function

Open the configuration for the last column’s telemetry key.
In the data post-processing function field, paste the following code:

if(value>=25){
    return "{i18n:custom.my-widget.telemetry-value.high-temperature}";
}else if(value<=19){
    return "{i18n:custom.my-widget.telemetry-value.low-temperature}";
}else{
    return "{i18n:custom.my-widget.telemetry-value.normal-temperature}";
}

Click Save, then Add the widget to the dashboard. Save the dashboard.

Verify the result

The “Temperature range” column value updates dynamically based on the incoming telemetry: