---
title: "Localization"
slug: "081-core-localization"
updated: 2025-05-23T22:34:58Z
published: 2025-05-23T22:34:58Z
canonical: "docs.developer.comcast.com/081-core-localization"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.developer.comcast.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Localization

**Localization Module 0.8.1 | Core SDK**

## Overview

Methods for accessessing location and language preferences

## OpenRPC

Firebolt APIs are maintained in the [rdkcentral/firebolt-core-sdk](https://github.com/rdkcentral/firebolt-core-sdk) GitHub repository.

You can see this API in the [localization.json](https://github.com/rdkcentral/firebolt-core-sdk/blob/main/src/modules/localization.json) OpenRPC JSON-Schema document.

## Usage

To use the Localization module, you can import it into your project from the Firebolt SDK:

```
import { Localization } from '@firebolt-js/sdk'
```

## Methods

### additionalInfo

Get any platform-specific localization information, in an Map<string, string>

```
function additionalInfo(): Promise<object>
```

Promise resolution:

| Type | Description |
| --- | --- |
| `object` | the additional info |

**Examples**

Default Example

JavaScript:

```
import { Localization } from '@firebolt-js/sdk'

Localization.additionalInfo()
    .then(info => {
        console.log(info)
    })
```

Value of `info`:

```
{}
```

**JSON-RPC:**

Request:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "localization.additionalInfo",
  "params": {}
}
```

Response:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {}
}
```

---

### countryCode

Get the ISO 3166 code for the counrty device is located in

```
function countryCode(): Promise<string>
```

Promise resolution:

| Type | Description |
| --- | --- |
| `string` | the device country code |

**Examples**

Default Example

JavaScript:

```
import { Localization } from '@firebolt-js/sdk'

Localization.countryCode()
    .then(code => {
        console.log(code)
    })
```

Value of `code`:

```
"US"
```

**JSON-RPC:**

Request:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "localization.countryCode",
  "params": {}
}
```

Response:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "US"
}
```

---

### language

Get the ISO 639 1/2 code for the preferred language

To get the value, call the method with no parameters:

```
function language(): Promise<string>
```

Promise resolution:

| Type | Description |
| --- | --- |
| `string` | the device language |

**Examples**

Default Example

JavaScript:

```
import { Localization } from '@firebolt-js/sdk'

Localization.language()
    .then(lang => {
        console.log(lang)
    })
```

Value of `lang`:

```
"en"
```

**JSON-RPC:**

Request:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "localization.language",
  "params": {}
}
```

Response:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "en"
}
```

To subscribe to notifications when the value changes, pass a function as the only parameter:

```
function language(subscriber: (lang: string) => void): Promise<boolean>
```

Parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| `subscriber` | `Function` | Yes | A callback that gets invoked when the value for language changes |

Promise resolution:

| Type | Summary |
| --- | --- |
| `listenerId` | The id of the listener that can be used with Localization.clear(listenerId) to unsubscribe |

Callback parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| `lang` | `string` | Yes | the device language |

**Examples**

Default Example

JavaScript:

```
import { Localization } from '@firebolt-js/sdk'

Localization.language(lang => {
  // property value was changed
  console.log(lang)
}).then(listenerId => {
  // you can clear this listener w/ Localization.clear(listenerId)
})
```

value of `lang`:

```
"en"
```

**JSON-RPC:**

Request:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "localization.onLanguageChanged",
  "params": {
    "listen": true
  }
}
```

Response:

```
{
  "jsonrpc": "2.0",
  "id": "1",
  "result": {
    "listening": "true"
  }
}
```

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "en"
}
```

---

### latlon

Get the approximate latitude and longitude coordinates of the device location

```
function latlon(): Promise<[number, number]>
```

Promise resolution:

| Type | Description |
| --- | --- |
| `[number, number]` | lat/long tuple |

**Examples**

Default Example

JavaScript:

```
import { Localization } from '@firebolt-js/sdk'

Localization.latlon()
    .then(latlong => {
        console.log(latlong)
    })
```

Value of `latlong`:

```
[
  39.9549,
  75.1699
]
```

**JSON-RPC:**

Request:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "localization.latlon",
  "params": {}
}
```

Response:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    39.9549,
    75.1699
  ]
}
```

---

### listen

Listen for events from this module.

To listen to a specific event pass the event name as the first parameter:

```
Localization.listen(event: string, (data: any) => void): Promise<number>
```

Parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| `event` | `string` | Yes | The event to listen for, see [Events](/docs/081-core-localization#events). |
| *callback* | `function` | Yes | A function that will be invoked when the event occurs. |

Promise resolution:

| Type | Description |
| --- | --- |
| `number` | Listener ID to clear the callback method and stop receiving the event, e.g. `Localization.clear(id)` |

Callback parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| `data` | `any` | Yes | The event data, which depends on which event is firing, see [Events](/docs/081-core-localization#events). |

To listen to all events from this module pass only a callback, without specifying an event name:

```
Localization.listen((event: string, data: any) => void): Promise<number>
```

Parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| *callback* | `function` | Yes | A function that will be invoked when the event occurs. The event data depends on which event is firing, see [Events](/docs/081-core-localization#events). |

Callback parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| `event` | `string` | Yes | The event that has occured listen for, see [Events](/docs/081-core-localization#events). |
| `data` | `any` | Yes | The event data, which depends on which event is firing, see [Events](/docs/081-core-localization#events). |

Promise resolution:

| Type | Description |
| --- | --- |
| `number` | Listener ID to clear the callback method and stop receiving the event, e.g. `Localization.clear(id)` |

See [Listening for events](/docs/listening-for-events/) for more information and examples.

---

### locale

Get the *full* BCP 47 code, including script, region, variant, etc., for the preferred langauage/locale

```
function locale(): Promise<string>
```

Promise resolution:

| Type | Description |
| --- | --- |
| `string` | the device locale |

**Examples**

Default Example

JavaScript:

```
import { Localization } from '@firebolt-js/sdk'

Localization.locale()
    .then(locale => {
        console.log(locale)
    })
```

Value of `locale`:

```
"en-US"
```

**JSON-RPC:**

Request:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "localization.locale",
  "params": {}
}
```

Response:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "en-US"
}
```

---

### locality

Get the locality/city the device is located in

```
function locality(): Promise<string>
```

Promise resolution:

| Type | Description |
| --- | --- |
| `string` | the device city |

**Examples**

Default Example

JavaScript:

```
import { Localization } from '@firebolt-js/sdk'

Localization.locality()
    .then(locality => {
        console.log(locality)
    })
```

Value of `locality`:

```
"Philadelphia"
```

**JSON-RPC:**

Request:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "localization.locality",
  "params": {}
}
```

Response:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "Philadelphia"
}
```

---

### once

Listen for only one occurance of an event from this module. The callback will be cleared after one event.

To listen to a specific event pass the event name as the first parameter:

```
Localization.once(event: string, (data: any) => void): Promise<number>
```

Parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| `event` | `string` | Yes | The event to listen for, see [Events](/docs/081-core-localization#events). |
| *callback* | `function` | Yes | A function that will be invoked when the event occurs. |

Promise resolution:

| Type | Description |
| --- | --- |
| `number` | Listener ID to clear the callback method and stop receiving the event, e.g. `Localization.clear(id)` |

Callback parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| `data` | `any` | Yes | The event data, which depends on which event is firing, see [Events](/docs/081-core-localization#events). |

To listen to all events from this module pass only a callback, without specifying an event name:

```
Localization.once((event: string, data: any) => void): Promise<number>
```

Parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| *callback* | `function` | Yes | A function that will be invoked when the event occurs. The event data depends on which event is firing, see [Events](/docs/081-core-localization#events). |

Callback parameters:

| Param | Type | Required | Summary |
| --- | --- | --- | --- |
| `event` | `string` | Yes | The event that has occured listen for, see [Events](/docs/081-core-localization#events). |
| `data` | `any` | Yes | The event data, which depends on which event is firing, see [Events](/docs/081-core-localization#events). |

Promise resolution:

| Type | Description |
| --- | --- |
| `number` | Listener ID to clear the callback method and stop receiving the event, e.g. `Localization.clear(id)` |

See [Listening for events](/docs/listening-for-events/) for more information and examples.

---

### postalCode

Get the postal code the device is located in

```
function postalCode(): Promise<string>
```

Promise resolution:

| Type | Description |
| --- | --- |
| `string` | the device postal code |

**Examples**

Default Example

JavaScript:

```
import { Localization } from '@firebolt-js/sdk'

Localization.postalCode()
    .then(postalCode => {
        console.log(postalCode)
    })
```

Value of `postalCode`:

```
"19103"
```

**JSON-RPC:**

Request:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "localization.postalCode",
  "params": {}
}
```

Response:

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "19103"
}
```

---

## Events

### Additional events

The following events are documented as part of a related set of method APIs.

For more information, follow the links under the "Documentation" column.

| JavaScript | RPC | Payload | Documentation |
| --- | --- | --- | --- |
| languageChanged | onLanguageChanged | string | [language](/docs/081-core-localization#language) |

## Schemas

### LatLon

```
type LatLon = [number, number]
```

---