Improving Consistency and Flexibility in Locale Resolution

Oct 13, 2025 by leolavanderia.com.br 89 views

Feature Request: Enhancing URL Resolution Logic and Dynamic Supported Locales in inlang-paraglide-js

What Problem Does the Feature Solve?

Improving Consistency and Flexibility in Locale Resolution

The inlang-paraglide-js library has been a game-changer for many developers, providing a seamless way to manage internationalization and localization in their applications. However, with the introduction of the 2.0.0-beta.27 release, the url strategy for determining the request locale has been deprecated. This change, while desirable in many cases, has created a challenge for developers working on SvelteKit applications where resource endpoints are collocated with the routes themselves.

The Need for a Flexible Locale Resolution Strategy

In a typical SvelteKit application, the cookie strategy could be used as a workaround to determine the locale for API requests. However, this approach may not be ideal, as it relies on setting the locale cookie on the initial document request and then relying on that for locale resolution in subsequent API requests. A more elegant solution would be to use the same resolution logic for both cases, ensuring consistency and reducing the complexity of locale management.

Dynamic Supported Locales in Multi-Tenant Applications

Another issue that has been encountered is the need to support dynamic locales in multi-tenant applications. In such scenarios, different tenants can have different supported locales, which can only be reliably retrieved at runtime, not build time. This requires implementing custom logic for resolving the tenant-specific locale and then passing a new Request to the paraglideMiddleware to set the expected locale in the AsyncLocalStorage.

What Does the Proposed API Look Like?

Configurable URL Strategy and Supported Locales

To address these issues, we propose the following enhancements to the inlang-paraglide-js API:

1. Configurable URL Strategy

Allow developers to configure which URL paths to apply the url strategy to, either through the paraglideVitePlugin or paraglideMiddleware options. This can be achieved by introducing a new ignorePathPatterns option, which can be used to specify the URL paths that should be excluded from the url strategy.

paraglideVitePlugin({
    strategy: ["url"],
    urlStrategy: {
        ignorePathPatterns: [/^\/api\/.+/],
    },
});

2. Configurable Supported Locales

Allow developers to configure the supported locales and default locale for a given request, either through the paraglideMiddleware options or by passing a subset of locales as the valid locales. This can be achieved by introducing a new supportedLocales option, which can be used to specify the locales that are supported for a given request.

type Locale = "en" | "de" | "ja";

interface Options {
    disableAsyncLocalStorage?: boolean;
    supportedLocales?: Locale[];
}

paraglideMiddleware(
    request,
    ({ locale }) => {
        // ...
    },
    {
        supportedLocales: ["en", "de"], // e.g. the tenant for this request only supports `en` and `de`
    },
);

Benefits of the Proposed API

The proposed API enhancements offer several benefits, including:

Improved consistency in locale resolution
Increased flexibility in configuring the URL strategy and supported locales
Simplified management of dynamic locales in multi-tenant applications

By introducing these enhancements, we can make inlang-paraglide-js an even more powerful and versatile library for managing internationalization and localization in modern web applications.
Q&A: Enhancing URL Resolution Logic and Dynamic Supported Locales in inlang-paraglide-js

Frequently Asked Questions

Q: What is the current issue with the url strategy in inlang-paraglide-js?

A: The url strategy for determining the request locale has been deprecated in the 2.0.0-beta.27 release. This change has created a challenge for developers working on SvelteKit applications where resource endpoints are collocated with the routes themselves.

Q: Why is the cookie strategy not ideal for determining the locale in SvelteKit applications?

A: The cookie strategy relies on setting the locale cookie on the initial document request and then relying on that for locale resolution in subsequent API requests. This approach may not be ideal, as it can lead to inconsistencies and complexity in locale management.

Q: How does the proposed API enhancement address the issue of dynamic supported locales in multi-tenant applications?

A: The proposed API enhancement allows developers to configure the supported locales and default locale for a given request, either through the paraglideMiddleware options or by passing a subset of locales as the valid locales. This enables developers to manage dynamic locales in multi-tenant applications more efficiently.

Q: What are the benefits of the proposed API enhancement?

A: The proposed API enhancement offers several benefits, including:

Improved consistency in locale resolution
Increased flexibility in configuring the URL strategy and supported locales
Simplified management of dynamic locales in multi-tenant applications

Q: How can developers configure the URL strategy and supported locales using the proposed API enhancement?

A: Developers can configure the URL strategy and supported locales using the following options:

ignorePathPatterns: specifies the URL paths that should be excluded from the url strategy
supportedLocales: specifies the locales that are supported for a given request

Q: What is the expected outcome of implementing the proposed API enhancement?

A: The expected outcome of implementing the proposed API enhancement is improved consistency and flexibility in locale resolution, as well as simplified management of dynamic locales in multi-tenant applications.

Additional Resources

Get Involved

Share your thoughts and feedback on the proposed API enhancement
Contribute to the development of the inlang-paraglide-js library
Help shape the future of internationalization and localization in modern web applications