Next-translate: Plural formats

[josephfarina]

Hey again,

Can different plural formats be used? The translating service we use doesn't support the current _plural style syntax. The current way is:

{
  "plural-example": "This is singular because the value is {{count}}",
  "plural-example_0": "Is zero because the value is {{count}}",
  "plural-example_2": "Is two because the value is {{count}}",
  "plural-example_plural": "Is in plural because the value is {{count}}"
}

Is there a way to use the ICU format:

plural-example: "{count, plural, one {This is singular because the value is {count}} other {Is in plural because the value is {count}}}"

Or the Rails style of:

{
  "plural-example: {
    "one": "This is singular because the value is {{count}}",
    "other": "Is in plural because the value is {{count}}"
  }
}

Thanks!

[aralroca]

@josephfarina On version 0.x the support of plurals is quite simple. In version 1.0 we support 6 plural forms (taken from CLDR Plurals page) by adding to the key this suffix:

• _zero
• _one (singular)
• _two (dual)
• _few (paucal)
• _many (also used for fractions if they have a separate class)
• _other (required—general plural form—also used if the language only has a single form)

_See more info about plurals here_.

Only the last one, _other, is required because it’s the only common plural form used in all locales. This is the equivalent of _plural on 0.x version.

All other plural forms depends on locale. For example English has only two: _one and _other (1 cat vs. 2 cats). Some languages have more, like Russian and Arabic.

In addition, we also support an exact match by specifying the number (_0, _999) and this works for all locales. Here is an example:

Code:

// Note: Only works if the name of the variable is {{count}}.
t('cart-message', { count })

Namespace:

{
  "cart-message_0": "The cart is empty", // when count === 0
  "cart-message_one": "The cart has only {{count}} product", // singular
  "cart-message_other": "The cart has {{count}} products", // plural
  "cart-message_999": "The cart is full", // when count === 999
}

The version 1.0 right now is under prerelease 1.0.0-canary.2, if you want you can start using it, I suppose that the final version will be released in a few days.

Useful links:

• How to migrate 0.x to 1.0
• Getting started with 1.0
• Plurals in 1.0
• Examples with 1.0

[josephfarina]

This is great information. Thank you @aralroca! Just one follow up question. Is it possible to define the one/other keys as children of the key?

Something like this:

{
  "cart-message": {
    "one": "The cart has only {{count}} product", // singular
    "other": "The cart has {{count}} products", // plural
  }
}

[aralroca]

@josephfarina No... You could do it with a workaround but it would not be directly supported...

const pluralForm = new Intl.PluralRules(lang).select(count)
const plural = t('cart-message', { count }, { returnObjects: true })[pluralForm]

Why? Does your translating service require this structure? If it's something strictly necessary we could look at implementing it. Which is the translation service?

[josephfarina]

Hey @aralroca so I just confirmed that the translating service we use, Smartling, does in fact require it to be nested. Or use the ICU format ("{people_count, plural, one {{people_count} person here.} other {{people_count} people here.}}").

Do you think this is something that is relatively easy to implement? I could take a look, but wouldn't know where to start...

[aralroca]

@josephfarina If you want to implement it, the first point to start would be to add the tests of these cases:

• https://github.com/vinissimus/next-translate/blob/canary/__tests__/useTranslation.test.js

And once you have the failed tests, then you must surely touch this part of the code to make the tests work:

• https://github.com/vinissimus/next-translate/blob/canary/src/I18nProvider.tsx#L37-L53

You can run the test with yarn test, and you can also test against the repo examples with yarn example. And your PR should be done to the canary branch. 😊

[josephfarina]

@aralroca I think I figured it out 😄 Let me know if this is what you imagined! https://github.com/vinissimus/next-translate/pull/368

[aralroca]

It is admirable how fast you have been. The PR looks good, I did a couple of comments, but I see it well. Good job and welcome as a first-time contributor!

[aralroca]

@josephfarina I prereleased 1.0.0-canary.5 with your change