Get fallback locale from locale chain

[frederikheld]

I have data from the database that is structured like this:

{
  data: {
    i18n: {
      'de-DE': {
        foo: 'Foo in German'
      },
      'en-US': {
        foo: 'Foo'
      }
    }
  }
}

I wrote a recursive function that looks for i18n keys and returns the data reduced to the current locale.

The above object for the locale 'de-DE' would be reduced to

{
  data: {
    foo: 'Foo in German'
  }
}

Now I would like to add support for fallback locales, so if a data key in the object is i18n['de'] instead of i18n['de-DE'], it should fall back to that locale and ultimately to the default locale configured in the plugin options (which is en-US).

Unfortunately I can't figure out how to get that configuration out of the i18n library. I found the fallbackWithLocaleChain function in the API docs but I can't figure out how to import it or how to set it up with a CoreContext properly.

Can anyone give me a hint how to approach that?

EDIT:

After digging through the source code, I figured out that I have to import it from a different package like this: import { fallbackWithLocaleChain } from '@intlify/core-base'. So the first problem is solved. But how do I use this function?

[frederikheld]

I figured it out:

import { useI18n } from 'vue-i18n'
import { fallbackWithLocaleChain, createCoreContext } from '@intlify/core-base'

const { locale, fallbackLocale } = useI18n()

// function start

        const fallbackChain = fallbackWithLocaleChain(
          createCoreContext({}),
          fallbackLocale.value as string,
          locale.value
        )

        for (let i = 0; i < fallbackChain.length; i++) {
          if (value[fallbackChain[i]]) {
            return value[fallbackChain[i]]
          }
        }

        return undefined

// function end

If there's a simpler (maybe built-in) way to do this, please let me know.