1 files changed, 78 insertions, 0 deletions
diff --git a/shared/localization/src/getLocAttributes.ts b/shared/localization/src/getLocAttributes.ts
new file mode 100644
index 0000000..2f462db
--- /dev/null
+++ b/shared/localization/src/getLocAttributes.ts
@@ -0,0 +1,78 @@
+import { getPageDir } from './getPageDir';
+
+/**
+ * Checks if a string contains language script
+ * ex. "zh-Hant-HK", "zh-Hant-TW", "zh-Hans-CN"
+ * @param {string} locale
+ * @returns {boolean}
+ */
+const hasSupportedLanguageScript = (locale: string): boolean => {
+    const SUPPORTED_SCRIPTS = ['-hans-', '-hant-'];
+
+    const formattedLocale = locale.toLowerCase();
+    return SUPPORTED_SCRIPTS.some((item) => formattedLocale.includes(item));
+};
+
+/**
+ *
+ * BCP47 https://www.w3.org/International/articles/language-tags/
+ *
+ * @param {string} language https://en.wikipedia.org/wiki/ISO_639
+ * @param {string} region https://en.wikipedia.org/wiki/ISO_3166-1
+ * @param {string} script https://en.wikipedia.org/wiki/ISO_15924
+
+ */
+const buildBcp47String = (
+    language: string,
+    region: string,
+    script?: string,
+): string => {
+    let capitalizeScript: string | null = null;
+    if (script) {
+        capitalizeScript =
+            script[0].toUpperCase() + script.substring(1).toLowerCase();
+    }
+    let bcp47Arr = [
+        language.toLowerCase(),
+        capitalizeScript,
+        region.toUpperCase(),
+    ];
+
+    return bcp47Arr.filter((item) => item !== null).join('-');
+};
+
+/**
+ * @description
+ * get values to be used in <html> tag lang and dir attributes.
+ *
+ * @param {string} locale
+ * @returns { { dir: 'rtl' | 'ltr', lang: string }} HTML dir + lang values
+ */
+
+export function getLocAttributes(locale: string): {
+    dir: 'rtl' | 'ltr';
+    lang: string;
+} {
+    const pageDir = getPageDir(locale);
+    let bcp47 = locale;
+
+    const localeStrings = locale.split('-');
+
+    // region index in array
+    const regionIndex = hasSupportedLanguageScript(locale) ? 2 : 1;
+
+    const language = localeStrings[0];
+    const script = hasSupportedLanguageScript(locale)
+        ? localeStrings[1]
+        : undefined;
+    const region = localeStrings[regionIndex];
+
+    if (language && region) {
+        bcp47 = buildBcp47String(language, region, script);
+    }
+
+    return {
+        dir: pageDir,
+        lang: bcp47,
+    };
+}