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Internationalize Javascript code


You can start using Transifex Native by creating a Transifex Native project.

Localization syntax

Transifex Native supports the ICU Message Format. Phrases for localization should be encapsulated in the t function as shown in the example below.

import { t } from '@transifex/native';

t('Hello <b>{username}</b>', { username: 'Joe' });

Parameters and metadata

Several parameter keys can be used in order to annotate the string with metadata that will be used in Transifex. The supported parameter keys are:

  • _context, to define additional context for the specific phrase. You can add a list of strings and separate them with a comma. Context data will be visible in the context tab of the editor.
  • _comment, to provide instructions to the localization team working on this phrase. This information is displayed in the editor's translation area as string instructions.
  • _charlimit, to add a character limit count for the translations. This information is displayed both in the editor's context tab and in the translation area.
  • _tags, to define tag-keywords that can help the localization team organize their work better over phrases. To add multiple tags use a comma-separator. Tags are visible in the editor's context tab. Read more about tags.
  • _key, to define a custom string key instead of an auto-generated one based on source phrase.

Learn more on how metadata can improve the localization process by reading about character limits, developer comments and tags in Transifex documentation.

NOTE: Defining context makes it possible to distinguish between two identical source strings and disambiguate the translation.

Metadata examples

t('Contact us', { 
  _context: 'Support page CTA',  
  _tags: 'important,footer',

t('A string', {
  _comment: 'A comment to the translators',
  _charlimit: 30,
  _tags: 't1,t2',

Escaping translations

Using the translation as is from the t function inside HTML is dangerous for XSS attacks. The translation must be escaped based on two scenarios.

Escaping text translations

Escape the entire phrase using the escape function.

import { t, escape } from '@transifex/native';

const translation = escape(t('Hello {username}', { username }));
// translation is safe to include in HTML

Escaping HTML source

HTML source content cannot be globally escaped. In that case, we can just escape the ICU variables using the _escapeVars parameter.

const html = t('<b>Hello {username}</b>', {
  username: username,
  _escapeVars: true,