Documentation: getLocalizedUrl Function in intlayer

Description

The getLocalizedUrl function generates a localized URL by prefixing the given URL with the specified locale. It handles both absolute and relative URLs, ensuring that the correct locale prefix is applied based on the configuration.

Key Features:

• Only 2 parameters are required: url and currentLocale
• 3 optional parameters: locales, defaultLocale, and prefixDefault
• Uses your project's internationalization configuration as defaults
• Can be used with minimal parameters for simple cases or fully customized for complex scenarios

Function Signature

getLocalizedUrl(  url: string,                   // Required  currentLocale: Locales,        // Required  locales?: Locales[],           // Optional  defaultLocale?: Locales,       // Optional  prefixDefault?: boolean        // Optional): string

Parameters

Required Parameters

• url: string

  • Description: The original URL string to be prefixed with a locale.
  • Type: string
  • Required: Yes

• currentLocale: Locales

  • Description: The current locale for which the URL is being localized.
  • Type: Locales
  • Required: Yes

Optional Parameters

• locales?: Locales[]

  • Description: Array of supported locales. If not provided, uses the configured locales from your project configuration.
  • Type: Locales[]
  • Required: No (Optional)
  • Default: Project Configuration

• defaultLocale?: Locales

  • Description: The default locale for the application. If not provided, uses the configured default locale from your project configuration.
  • Type: Locales
  • Required: No (Optional)
  • Default: Project Configuration

• prefixDefault?: boolean

  • Description: Whether to prefix the URL for the default locale. If not provided, uses the configured value from your project configuration.
  • Type: boolean
  • Required: No (Optional)
  • Default: Project Configuration

Returns

• Type: string
• Description: The localized URL for the specified locale.

Example Usage

Basic Usage (Only Required Parameters)

When you have configured your project with internationalization settings, you can use the function with just the required parameters:

import { getLocalizedUrl, Locales } from "intlayer";// Uses your project's configuration for locales, defaultLocale, and prefixDefaultgetLocalizedUrl("/about", Locales.FRENCH);// Output: "/fr/about" (assuming French is supported in your config)getLocalizedUrl("/about", Locales.ENGLISH);// Output: "/about" or "/en/about" (depending on your prefixDefault setting)

Advanced Usage (With Optional Parameters)

You can override the default configuration by providing optional parameters:

Relative URLs (All Parameters Specified)

import { getLocalizedUrl, Locales } from "intlayer";// Explicitly providing all optional parametersgetLocalizedUrl(  "/about",  Locales.FRENCH,  [Locales.ENGLISH, Locales.FRENCH], // locales  Locales.ENGLISH, // defaultLocale  false // prefixDefault);// Output: "/fr/about" for the French locale// Output: "/about" for the default (English) locale

Partial Configuration Override

You can also provide only some of the optional parameters. The function will use your project configuration for any parameters you don't specify:

import { getLocalizedUrl, Locales } from "intlayer";// Only override the locales, use project config for defaultLocale and prefixDefaultgetLocalizedUrl(  "/about",  Locales.SPANISH,  [Locales.ENGLISH, Locales.FRENCH, Locales.SPANISH] // Only specify locales);// Only override prefixDefault, use project config for locales and defaultLocalegetLocalizedUrl(  "/about",  Locales.ENGLISH,  undefined, // Use project config for locales  undefined, // Use project config for defaultLocale  true // Force prefix for default locale);

Absolute URLs

getLocalizedUrl(  "https://example.com/about",  Locales.FRENCH, // Current Locale  [Locales.ENGLISH, Locales.FRENCH], // Supported Locales  Locales.ENGLISH, // Default Locale  false // Prefix Default Locale); // Output: "https://example.com/fr/about" for the FrenchgetLocalizedUrl(  "https://example.com/about",  Locales.ENGLISH, // Current Locale  [Locales.ENGLISH, Locales.FRENCH], // Supported Locales  Locales.ENGLISH, // Default Locale  false // Prefix Default Locale); // Output: "https://example.com/about" for the EnglishgetLocalizedUrl(  "https://example.com/about",  Locales.ENGLISH, // Current Locale  [Locales.ENGLISH, Locales.FRENCH], // Supported Locales  Locales.ENGLISH, // Default Locale  true // Prefix Default Locale); // Output: "https://example.com/en/about" for the English

Unsupported Locale

getLocalizedUrl(  "/about",  Locales.ITALIAN, // Current Locale  [Locales.ENGLISH, Locales.FRENCH], // Supported Locales  Locales.ENGLISH // Default Locale); // Output: "/about" (no prefix applied for unsupported locale)

Edge Cases

• No Locale Segment:

  • If the URL does not contain any locale segment, the function safely prefixes the appropriate locale.

• Default Locale:

  • When prefixDefault is false, the function does not prefix the URL for the default locale.

• Unsupported Locales:

  • For locales not listed in locales, the function does not apply any prefix.

Usage in Applications

In a multilingual application, configuring the internationalization settings with locales and defaultLocale is critical for ensuring the correct language is displayed. Below is an example of how getLocalizedUrl can be used in an application setup:

import { Locales, type IntlayerConfig } from "intlayer";// Configuration for supported locales and default localeexport default {  internationalization: {    locales: [Locales.ENGLISH, Locales.FRENCH, Locales.SPANISH],    defaultLocale: Locales.ENGLISH,  },} satisfies IntlayerConfig;export default config;

The above configuration ensures that the application recognizes ENGLISH, FRENCH, and SPANISH as supported languages and uses ENGLISH as the fallback language.

Using this configuration, the getLocalizedUrl function can dynamically generate localized URLs based on the user's language preference:

getLocalizedUrl("/about", Locales.FRENCH); // Output: "/fr/about"getLocalizedUrl("/about", Locales.SPANISH); // Output: "/es/about"getLocalizedUrl("/about", Locales.ENGLISH); // Output: "/about"

By integrating getLocalizedUrl, developers can maintain consistent URL structures across multiple languages, enhancing both user experience and SEO.

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