Phrasebook

A lightweight translation library for React/Preact projects with a similar interface to react-i18next.

Made with ❤️ by loveholidays.com

Why phrasebook?

• Tree-shakeable
• Similar interface to react-i18next
• Native ESM module with TypeScript type definitions
• Small bundle size (~1kb)

This package exports native ESM and does not provide a CommonJS export.

Bundle size comparisons

Package	Bundle size (gzip)	Difference
@loveholidays/phrasebook	1.1kb	baseline
@lingui/[email protected]	1.4kb	+ 27%
[email protected]	5.3kb	+ 482%

Installation

Currently available on NPM:

$ npm i -S @loveholidays/phrasebook
- or -
$ yarn add @loveholidays/phrasebook

Using a dev version of Phrasebook in a dev app

We can use yalc for this, which creates a local store that we can publish and pull dependencies from.

To publish Phrasebook to the local store:

npx --yes yalc publish

In your target repo (eg. sunrise), update the dependency to local Phrasebook:

npx yalc add @loveholidays/phrasebook

If you make a change in your local Phrasebook repo, update the local store and the target repo:

npx yalc publish --push

To reset the dependency of Phraseboook, in your target repo run:

npx yalc remove @loveholidays/phrasebook

Usage

Use the TranslationProvider to create the localisation context:

import { TranslationProvider } from '@loveholidays/phrasebook';

const App = () => (
  <TranslationProvider
    locale="en-gb"
    translations={translations}
    onError={(errorType, data) => {
      const { key, argumentName } = data;
    }}
  >
    // ...
  </TranslationProvider>
);

The locale string is used for locale specific number formatting. The translations object follows a format similar to the i18next JSON format with some exceptions.

Use the useTranslation hook to access the translation function:

import { useTranslation } from '@loveholidays/phrasebook';

const MyComponent = () => {
  const { t } = useTranslation();

  return (
    <>
      <h1>{t('helloWorld')}</h1>
      <h2>{t('welcomeBack', { name: 'David' })}</h2>
      <p>{t('youHaveXNewMessages', { count: 14 })}</p>
    </>
  );
};

Use the Translation component to embed React components into the translations (similar to the Trans component of react-i18next):

import { Translation } from '@loveholidays/phrasebook';

const MyComponent = () => (
  <p>
    <Translation
      translationKey="myKey" // "Read all the {count} reviews <1>here</1>, served by: <2>"
      params={{
        count: 1234,
      }}
      components={[
        (text) => <a href="/#">{text}</a>, // text between <1> and </1> is passed in as a param
        <img src="logo.svg" />,
      ]}
    />
  </p>
);

// result: <p>Read all the 1234 reviews <a href="/#">here</a>, served by: <img src="logo.svg" /></p>

Differences to i18next

The goal is to provide a lightweight alternative for the most common used features of react-i18next, although phrasebook won't ever be 100% compatible with that.

• There is no support for translation backends, the translation object must be loaded and passed in to the TranslationProvider.
• The translation object format is not fully compatible with the i18next JSON format, the currently supported features are: nested translations, _plural suffix, contexts.

Namespaces

Namespaced translations can be used with <TranslationProvider /> by passing an object into the namespaces prop - where the keys are the names of the namespaces and the values are the translations for the given namespace:

<TranslationProvider
  locale={locale}
  namespaces={{
    homepage: {
      title: 'Homepage',
    },
    checkout: {
      title: 'Checkout',
    },
  }}
>

The ns option controls the namespace when using the t function:

const { t } = useTranslation();

const homepageTitle = t('title', { ns: 'homepage' });
const checkoutTitle = t('title', { ns: 'checkout' });

To avoid repeating the ns option when using t, the default namespace can be changed when using the useTranslation hook:

const { t } = useTranslation('homepage');

const homepageTitle = t('title');
const checkoutTitle = t('title', { namespace: 'checkout' });

The Translation component takes an optional namespace prop to achieve the same:

  <Translation
    translationKey="myKey"
    namespace="myNamespace"
    params={ ... }
    components={ ... }
  />

i18n ally extension support for VS Code

We highly recommend to use the i18n ally extension for VS Code users. To make it work with phrasebook you need to add this file to your project:

# .vscode/i18n-ally-custom-framework.yml

languageIds:
  - javascript
  - typescript
  - javascriptreact
  - typescriptreact
usageMatchRegex:
  - "[^\\w\\d]t\\(['\"`]({key})['\"`]"
monopoly: false

Contributing

Please see our contributing guidelines