tezx/middleware/detectLocale.js

TezX is a high-performance, lightweight JavaScript framework designed for speed, scalability, and flexibility. It enables efficient routing, middleware management, and static file serving with minimal configuration. Fully compatible with Node.js, Deno, an

import { GlobalConfig } from "../core/config.js";
export const detectLocale = (options) => {
    const { supportedLocales, defaultLocale = "en", queryKeyLocale = "lang", cookieKeyLocale = "locale", localeContextKey = "locale", customLocaleDetector, } = options;
    return async function detectLocale(ctx, next) {
        let detectedLocale;
        const queryLocale = ctx.req.query[queryKeyLocale];
        if (queryLocale && supportedLocales.includes(queryLocale)) {
            detectedLocale = queryLocale;
        }
        if (!detectedLocale) {
            const cookieLocale = ctx.cookies.get(cookieKeyLocale);
            if (cookieLocale && supportedLocales.includes(cookieLocale)) {
                detectedLocale = cookieLocale;
            }
        }
        if (!detectedLocale) {
            const acceptLanguage = ctx.req.headers.get("accept-language");
            if (acceptLanguage) {
                const preferredLocales = acceptLanguage
                    .split(",")
                    .map((lang) => lang.split(";")[0].trim())
                    .filter((lang) => supportedLocales.includes(lang));
                detectedLocale = preferredLocales[0];
            }
        }
        if (!detectedLocale && customLocaleDetector) {
            const customLocale = customLocaleDetector(ctx);
            if (customLocale && supportedLocales.includes(customLocale)) {
                detectedLocale = customLocale;
            }
        }
        if (!detectedLocale) {
            detectedLocale = defaultLocale;
        }
        ctx[localeContextKey] = detectedLocale;
        GlobalConfig.debugging.success(`Detected locale: ${detectedLocale}`);
        return await next();
    };
};