Initial Commit

packages/localization/i18n/i18n-detector/src/default-chain/default-chain.ts

@@ -0,0 +1,55 @@
+import type { LocaleDetector } from "../detector.types.js";
+import { acceptLanguageDetector } from "../detectors/accept-language/accept-language.js";
+import { cloudflareIpGeoDetector } from "../detectors/cloudflare-ip-geo/cloudflare-ip-geo.js";
+import { cookieDetector } from "../detectors/cookie/cookie.js";
+import { fallbackDetector } from "../detectors/fallback/fallback.js";
+import { htmlLangDetector } from "../detectors/html-lang/html-lang.js";
+import { localStorageDetector } from "../detectors/local-storage/local-storage.js";
+import { navigatorDetector } from "../detectors/navigator/navigator.js";
+import { querystringDetector } from "../detectors/querystring/querystring.js";
+import { userPreferenceDetector } from "../detectors/user-preference/user-preference.js";
+import type { DefaultDetectorChainOptions } from "./default-chain.types.js";
+
+/**
+ * Build the canonical 9-entry (or 8-entry) detector chain consumed
+ * by `<TranslationProvider>` and `useLocaleDetection`.
+ *
+ * Order (per spec "Default chain order"):
+ *
+ * 1. `querystring`
+ * 2. `userPreference` — only when `opts.userPreferenceEndpoint` is set
+ * 3. `cookie`
+ * 4. `localStorage`
+ * 5. `htmlLang`
+ * 6. `acceptLanguage`
+ * 7. `navigator`
+ * 8. `cloudflareIpGeo`
+ * 9. `fallback`
+ *
+ * The chain is returned as a fresh array on every call so callers
+ * can mutate or filter the result without affecting subsequent
+ * invocations.
+ */
+export function defaultDetectorChain(
+    options: DefaultDetectorChainOptions
+): LocaleDetector[] {
+    const detectors: LocaleDetector[] = [querystringDetector()];
+    if (
+        typeof options.userPreferenceEndpoint === "string" &&
+        options.userPreferenceEndpoint !== ""
+    ) {
+        detectors.push(
+            userPreferenceDetector({
+                endpoint: options.userPreferenceEndpoint,
+            })
+        );
+    }
+    detectors.push(cookieDetector());
+    detectors.push(localStorageDetector());
+    detectors.push(htmlLangDetector());
+    detectors.push(acceptLanguageDetector());
+    detectors.push(navigatorDetector());
+    detectors.push(cloudflareIpGeoDetector());
+    detectors.push(fallbackDetector(options.fallback));
+    return detectors;
+}