Other Strategies

Appart from the default Prefix Routing Stragegy there are a few others available:

Domain Strategy

This Strategy uses the domain of a request to determine the language.

import { DomainStrategy } from "@inlang/paraglide-next"
import type { AvailableLanguageTag } from "@/paraglide/runtime"

const strategy = DomainStrategy<AvailableLanguageTag>({
	domains: {
		en: "https://example.com",
		de: "https://example.de",
		fr: "https://fr.example.com",
	},
})

Domains must be unique for each language.

Detection-only Strategy

This strategy exclusively uses the Accept-Language header to detect the language on first visit. Any subsequent visits will use the language set in the NEXT_LOCALE cookie. Routing is not affected in any way.

import { DetectionStrategy } from "@inlang/paraglide-next"
import type { AvailableLanguageTag } from "@/paraglide/runtime"

const strategy = DetectionStrategy<AvailableLanguageTag>()

Manual Language switches only work if JS is enabled when using this strategy.

Custom Strategy

The beatuy of the RoutingStrategy interface is that you can easily create your own routing strategy. All you need to do is implement the following functions:

const MyStrategy: RoutingStrategy<AvailableLanguageTag> = {
	/**
	 * This function is called inside the middleware to determine the language for the current request.
	 *
	 * It's also OK to say you don't know & return undefined. In that case the Language Cookie will be used,
	 * or Language negotiation if no cookie is present.
 	 */
	resolveLocale(request: NextRequest) : AvailableLanguageTag | undefined

	/**
	 * Returns the canonical pathname based on the localised pathname and it's language.
	 *
	 * The canonical pathname is the pathname you would need to get to the page you want
	 * in the `app/` directory if there weren't any i18n routing.
	 *
	 * @example /de/ueber-uns + de -> /about
	 *
	 */
	getCanonicalPath(
		localisedPath: `/${string}`,
		locale: AvailableLanguageTag
	): `/${string}`


	/**
	 * Returns the localized URL that can be used to navigate to the given path in the given language.
	 * It's a URL & not just a pathname so you can add query params and use other domains.
	 *
	 * For some strategies you might need to return different URLs based on if it's a language switch or not.
	 *
	 * @example /about + de -> /de/ueber-uns
	 */
	getLocalisedUrl(
		canonicalPath: `/${string}`,
		targetLocale: AvailableLanguageTag,
		isLanugageSwitch: boolean
	) : import("url").UrlObject
}

To get some inspiration you might want to read the source-code of the built-in strategies.