Function: fallbackChain()
fallbackChain(
locale,fallbacks,defaultLocale):string[]
List the languages a message of a language is looked up in, in their order, each once: the language, then each of its configured fallbacks (followed by their own fallbacks and less specific tags), then its less specific tags (zh-Hant-TW, zh-Hant, zh), then the default language (and its own fallbacks and less specific tags). The tags are not normalized: give canonical ones.
Parameters
locale
string
The language tag of the message asked.
fallbacks
Record<string, string[]>
The configured fallbacks, by language tag.
defaultLocale
string
The default language tag.
Returns
string[]
The language tags, in lookup order.
Example
typescript
import {fallbackChain} from 'lakutata/com/i18n'
console.log(fallbackChain('zh-TW', {'zh-TW': ['zh-CN']}, 'en')) //['zh-TW', 'zh-CN', 'zh', 'en']
console.log(fallbackChain('zh-Hant-TW', {}, 'en')) //['zh-Hant-TW', 'zh-Hant', 'zh', 'en']