grafana/contribute/internationalization.md

# Internationalization

Grafana uses the [i18next](https://www.i18next.com/) framework for managing translating phrases in the Grafana frontend.

## tl;dr

**Please note:** We do not currently accept contributions for translations. Please do not submit pull requests translating grafana.json files - they will be rejected. We do accept contributions to mark up phrases for translation.

- Use `<Trans i18nKey="search-results.panel-link">Go to {{ pageTitle }}</Trans>` in code to add a translatable phrase
- Translations are stored in JSON files in `public/locales/{locale}/grafana.json`
- If a particular phrase is not available in the a language then it will fall back to English
- To update phrases in English, edit the default phrase in both the component's source and the [English grafana.json message catalogue](../public/locales/en-US/grafana.json), then run `yarn i18n:extract`.
- To update phrases in any translated language, edit the phrase in Crowdin. Do not edit the `{locale}/grafana.json`

## How to add a new translation phrase

### JSX

1. For JSX children, use the `<Trans />` component from `app/core/internationalization` with the `i18nKey`, ensuring it conforms to the guidelines below, with the default english translation. e.g.

```jsx
import { Trans } from 'app/core/internationalization';

const SearchTitle = ({ term }) => (
  <Trans i18nKey="search-page.results-title">
    Results for <em>{{ term }}</em>
  </Trans>
);
```

Prefer using `<Trans />` for JSX children, and `t()` for props and other javascript usage.

When translating in grafana-ui, use a relative path to import `<Trans />` and `t()` from `src/utils/i18n`.

Note that our tooling must be able to statically analyse the code to extract the phrase, so the `i18nKey` can not be dynamic. e.g. the following will not work:

```jsx
const ErrorMessage = ({ id, message }) => <Trans i18nKey={`errors.${id}`}>There was an error: {{ message }}</Trans>;
```

2. Upon reload, the default English phrase will appear on the page.

3. Before submitting your PR, run the `yarn i18n:extract` command to extract the messages you added into the `grafana.json` file and make them available for translation.

### Plain JS usage

Sometimes you may need to translate a string cannot be represented in JSX, such as `placeholder` props. Use the `t` macro for this.

```jsx
import { t } from "app/core/internationalization"

const placeholder = t('form.username-placeholder','Username');

return <input type="value" placeholder={placeholder}>
```

Interpolating phrases is a bit more verbose. Make sure the placeholders in the string match the values passed in the object - there's no type safety here!

```jsx
const placeholder = t('page.greeting', 'Hello {{ username }}', { username });
```

While the `t` function can technically be used outside of React functions (e.g, in actions/reducers), aim to keep all UI phrases within the React UI functions.

## How to add a new language

1. Add new locale in Crowdin and sync files to repo
   1. Grafana OSS Crowdin project -> "dot dot dot" menu in top right -> Target languages
   2. Grafana OSS Crowdin project -> Integrations -> Github -> Sync Now
   3. If Crowdin's locale code is different from our IETF language tag, add a custom mapping in Project Settings -> Language mapping
2. Update `public/app/core/internationalization/constants.ts` (add new constant, and add to `LOCALES`)
3. Update `public/locales/i18next-parser.config.js` to add the new locale to `locales`
4. Run `yarn i18n:extract` and commit the result

## How translations work in Grafana

Grafana uses the [i18next](https://www.i18next.com/) framework for managing translating phrases in the Grafana frontend. It:

- Marks up phrases within our code for extraction
- Extracts phrases into messages catalogues for translating in external systems
- Manages the user's locale and putting the translated phrases in the UI

Grafana will load the message catalogue JSON before the initial render.

### Phrase ID naming convention

We set explicit IDs for phrases to make it easier to identify phrases out of context, and to track where they're used. IDs follow a naming scheme that includes _where_ the phrase is used. The exception is the rare case of single reoccuring words like "Cancel", but default to using a feature/phrase specific phrase.

Message IDs are made of _up to_ three segments in the format `feature.area.phrase`. For example:

- `dashboard.header.refresh-label`
- `explore.toolbar.share-tooltip`

For components used all over the site, use just two segments:

- `footer.update`
- `navigation.home`

### I18next context

We rely on a global i18next singleton (that lives inside the i18next) for storing the i18next config/context.

## Examples

See [i18next](https://www.i18next.com/) and [react-i18next](https://react.i18next.com/) documentation for more details.

### Basic usage

For fixed phrases:

```jsx
import { Trans } from 'app/core/internationalization';

<Trans i18nKey="page.greeting">Hello user!</Trans>;
```

To interpolate variables, include it as an object child. It's weird syntax, but Trans will do it's magic to make it work:

```jsx
import { Trans } from 'app/core/internationalization';

<Trans i18nKey="page.greeting">Hello {{ name: user.name }}!</Trans>;

const userName = user.name;
<Trans i18nKey="page.greeting">Hello {{ userName }}!</Trans>;
```

Variables must be strings (or, must support calling `.toString()`, which we almost never want).

```jsx
import { Trans } from 'app/core/internationalization';

// This will not work
const userName = <strong>user.name</strong>;
<Trans i18nKey="page.greeting">Hello {{ userName }}!</Trans>;

// Instead, put the JSX inside the phrase directly
const userName = user.name;
<Trans i18nKey="page.greeting">
  Hello <strong>{{ userName }}</strong>!
</Trans>;
```

### React components and HTML tags

Both HTML tags and React components can be included in a phase. The Trans function will handle interpolating it's children properly

```js
import { Trans } from "app/core/internationalization"

<Trans i18nKey="page.explainer">
  Click <button>here</button> to <a href="https://grafana.com">learn more.</a>
</Trans>

// ↓ is in the grafana.json file like ↓
{
  "page": {
    "explainer": "Click <0>here</0> to <1>learn more</1>"
  }
}
```

### Plurals

Plurals require special handling to make sure they can be translating according to the rules of each locale (which may be more complex that you think!). Use either the `<Trans />` component or the `t` function, with the `count` prop to provide a singular form.

```js
import { Trans } from 'app/core/internationalization';

<Trans i18nKey="inbox.heading" count={messages.length}>
  You got {{ count: messages.length }} message
</Trans>;
```

```js
import { t } from 'app/core/internationalization';

const translatedString = t('inbox.heading', 'You got {{count}} message', { count: messages.length });
```

Once extracted with `yarn i18n:extract` you will need to manually edit the [English grafana.json message catalogue](../public/locales/en-US/grafana.json) to correct the plural forms. See the [react-i18next docs](https://react.i18next.com/latest/trans-component#plural) for more details.

```json
{
  "inbox": {
    "heading__one": "You got {{count}} message",
    "heading__other": "You got {{count}} messages"
  }
}
```

## Documentation

[Grafana's documentation](https://grafana.com/docs/grafana/latest/) is not yet open for translation and should be authored in American English only.