grafana/contribute/internationalization.md

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# 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 for grafana.json files - they will be rejected.
- 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 the component's source, then run `yarn i18n:extract`. Do not edit the `en-ES/grafana.json` or update the english phrase in Crowdin
- 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
English phrases remain in our Javascript bundle in the source components (as the `<Trans />` or `t()` default phrase). At runtime, we don't need to load any messages for en-US. If the user's language preference is set to another language, Grafana will load that translations's messages 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 the `<Trans />` component, with the `count` prop.
```js
import { Trans } from 'app/core/internationalization';
<Trans i18nKey="newMessages" count={messages.length}>
You got {{ count: messages.length }} messages.
</Trans>;
```
Once extracted with `yarn i18n:extract` you will need to manually fill in the grafana.json message catalogues with the additional plural forms. See the [react-i18next docs](https://react.i18next.com/latest/trans-component#plural) for more details.
## Documentation
[Grafana's documentation](https://grafana.com/docs/grafana/latest/) is not yet open for translation and should be authored in American English only.