Internationalization (i18n) system

Documenting how we handle translations in the code

We use react-intl to manage our translations. They are extracted from the code to src/lang/${locale}.json files using the npm run build:langs command (CI will notify you if the translation files are outdated). Don't translate the strings directly in the files, we use Crowdin to manage our translatations.

Good practices

Use "select" when a value has a limited number of options

Example

<FormattedMessage
    defaultMessage="{action, select, delete {Delete this} archive {Archive this} other {Do something with this}}"
    values={{ action: 'delete' }}
/>

// => "Delete this"

<FormattedMessage
    defaultMessage="{action, select, delete {Delete this} archive {Archive this} other {Do something with this}}"
    values={{ action: 'eat' }}
/>

// => "Do something with this"

• defaultMessage string breakdown:

  • action variable name

  • select keyword

  • delete and archive possible values

  • other all other values will use this key

An exception to this rule: very common enums or the ones with many possible values should be implemented as a separate file listing all values because:

• Re-usability

• A map of translations is easier to read than a long select string with tons of options

See i18n-member-role as an example.

Don't assume word's order stays the same in other languages

The order of the words may change from a language to another. For this reason we must always pass the values to be replaced in values so their order can later be changed.

Example

// Bad
<div>
    <FormattedMessage id="str" defaultMessage="Pending approval from " />
    <Link route={`/${host.slug}`}>{host.name} </Link>
</div>

// Good
<div>
    <FormattedMessage  
        defaultMessage="Pending approval from {host}" 
        values ={{ 
          host: <Link route={`/${host.slug}`}>{host.name} </Link>
        }}
    />
</div>

Don't split strings

Splitting a string is alway problematic, because translators loose the context: the strings may not be next to each others when they'll be translated.

// Bad
<FormattedMessage
  defaultMessage="Do you want to {createSomething} in this list?"
  values={{
    createSomething: (
      <blink>
        <FormattedMessage defaultMessage="create something"/>
      </blink>
    )
  }}
/>

// Good
<FormattedMessage
  defaultMessage="Do you want to <blink>create something</blink> in this list?"
  values={{
    createSomething: function BlinkComponent(msg) {
      return (<blink>{msg}</blink>)
    }
  }}
/>

Use I18nFormatters to format rich text (bold, italic...etc)

import I18nFormatters from '../../I18nFormatters';

<FormattedMessage 
  id="_" 
  defaultMessage="This <strong>is</strong> <i>easier</i>." 
  values={I18nFormatters}
/>

Provide an ID when the translation depends on the context

In many Latin languages, the translation for a string like "Created at" will depend on the context because of the feminine/masculine forms. The best way to provide this context is to set an ID on the string:

<FormattedMessage
  id="expense.createdAt"
  defaultMessage"Created at"
/>

Translate links inline

In some parts of the code we translate links like this:

// Please don't do that!
<FormattedMessage
  defaultMessage="Please check our {documentationLink} to learn more!"
  values={{
    documentationLink: (
      <a href="https://docs.opencollective.com">
        <FormattedMessage id="documentation" defaultMessage="documentation" />
      </a>
    ),
  }}
/>

This is bad because we're creating two strings and translators loose the context when they translate one. You should do this instead:

import { getI18nLink } from './I18nFormatters';

// External link
<FormattedMessage
  defaultMessage="Please check our <link>documentation</link> to learn more!"
  values={{
    link: getI18nLink({ href: 'https://docs.opencollective.com' }),
  }}
/>

// Internal link
import Link from './Link';

<FormattedMessage
  defaultMessage="Please check <link>hosts page</link> to learn more!"
  values={{
    link: getI18nLink({ as: Link, route: 'hosts' }),
  }}
/>

FormattedMessage

The FormattedMessage component is the main way to translate strings. To use it, you just need to add the following import:

import { FormattedMessage } from 'react-intl'

Then you just add the component with an unique id and a defaultMessage.

For VSCode users, you can use the following snippet to make your life easier:

{
  "Formatted Message (react-intl)": {
    "scope": "javascript",
    "prefix": "formatted-message",
    "body": "<FormattedMessage id=\"$TM_FILENAME_BASE.$0\" defaultMessage=\"$1\"/>",
    "description": "Put the given string in a FormattedMessage"
  }
}

Add a new language

Add the language on Crowdin

Just go to https://crowdin.com/project/opencollective/settings#translations, click on Target languages pick the language and click Update.

Activate the language in the code

To activate a language on the website, we usually wait to have a correct translated ratio (20-30%). Then activate it by adding a new line in https://github.com/opencollective/opencollective-frontend/blob/main/lib/constants/locales.js.