bookorbit/docs/LOCALIZATION.md

Localization

BookOrbit uses Vue I18n catalogs under client/src/locales/. English is the source language, and Crowdin is the source of truth for German, Dutch, Brazilian Portuguese, and Slovenian translations.

Supported Catalogs

Application locale	Crowdin language ID	Catalog
English	Source language	en.json
German	de	de.json
Dutch	nl	nl.json
Brazilian Portuguese	pt-BR	pt.json
Slovenian	sl	sl.json

Crowdin's %two_letters_code% placeholder maps Brazilian Portuguese to pt, which matches BookOrbit's existing application locale and filename.

Adding User-Facing Copy

Feature branches must:

1. Add the source message to client/src/locales/en.json.
2. Add the same English value under the same key in every target catalog as a temporary fallback.
3. Preserve every placeholder and the plural-message structure.
4. Run pnpm --filter client validate:locales.

Do not create or improve target-language translations directly in Git. Crowdin does not continuously import repository translations after initial setup, so a later Crowdin export would overwrite those changes. Apply any emergency target-catalog fix in Crowdin before the next export.

When an English edit changes meaning rather than wording, prefer a new message key. If the key must remain, explicitly invalidate or clear the affected translations in Crowdin so an outdated translation is not exported for the new meaning.

Plural Messages

Vue I18n plural messages use pipe-separated branches:

No books | 1 book | {count} books

Crowdin's JSON parser treats this syntax as ordinary text. Translators must preserve the pipe-separated structure and placeholders manually. Locale branch counts can differ; Slovenian commonly needs more branches than English.

Repository validation rejects missing plural structure, empty plural branches, placeholder mismatches, embedded HTML, and Unicode em dash characters. Human review is still required for locale-specific plural semantics.

Translation Delivery

After an English source change reaches main:

1. Crowdin synchronizes client/src/locales/en.json.
2. Translators update target strings in Crowdin.
3. Crowdin exports the target catalogs to l10n_main.
4. Crowdin opens a pull request to main.
5. CI verifies that the pull request changes only the four target catalogs and runs the normal client checks.
6. A maintainer reviews and squash-merges the pull request.
7. The l10n_main service branch is deleted. Crowdin recreates it for the next export.

Crowdin pull requests must retain the configured i18n(client) title and commit format. The i18n commit type produces a patch release and an Internationalization release-note section. Crowdin's default [ci skip] commit suffix is disabled so pull-request validation runs before merge.

Adding a New Language

Add languages through a normal issue-linked pull request before enabling their Crowdin export. This ensures the application, validation, and Crowdin PR allowlist are ready before Crowdin creates the first translation update.

1. Choose the locale identifiers

Choose both:

• The application locale and catalog filename, preferably a canonical BCP 47 identifier such as fr or fr-CA.
• The exact Crowdin language ID shown in Crowdin's language-code reference.

Crowdin's export_languages entries use Crowdin language IDs, while %two_letters_code% controls the exported filename. If two enabled variants share the same two-letter code, or the application identifier differs from Crowdin's two-letter code, add a per-file languages_mapping entry in crowdin.yml so exports cannot collide. For example:

files:
  - source: /client/src/locales/en.json
    translation: /client/src/locales/%two_letters_code%.json
    languages_mapping:
      two_letters_code:
        fr-CA: fr-CA

Never enable two Crowdin languages that resolve to the same catalog path.

2. Register the application locale

Update packages/types/src/locale.ts:

• Add the application locale to SUPPORTED_LOCALES.
• Add its native-language display name to LOCALE_LABELS.
• Set ltr or rtl in LOCALE_DIRECTIONS.

The shared locale list automatically updates the language picker, server preference validation, and client locale typing. For an RTL language, manually verify the document direction and responsive layouts in addition to setting rtl.

3. Add the catalog and locale behavior

Create client/src/locales/<locale>.json with the exact key structure from en.json and English fallback values. Do not add partial catalogs. Crowdin will replace fallback values as translations are completed.

Review client/src/stores/locale.ts and add browser-locale matching coverage to client/src/stores/__tests__/locale.spec.ts, especially for regional variants. Vue I18n supplies standard locale pluralization; if the language needs a project-specific rule, register it in client/src/i18n/index.ts and add focused tests.

4. Allow Crowdin export and PR delivery

Update crowdin.yml:

• Add the exact Crowdin language ID to export_languages.
• Add languages_mapping when the desired filename is not the language's unique %two_letters_code% output.

Update scripts/classify-crowdin-pr.sh to allow the new target catalog path. Do not allow en.json or broaden the rule to the whole locales directory.

Before merging, add the target language in Crowdin while the current main configuration still excludes it from export_languages, or pause translation synchronization. Merge the repository support before allowing the first export. After merge, run a manual source and translation sync and confirm that the generated PR changes only explicitly allowed target catalogs.

5. Verify the new language

Run:

pnpm --filter @bookorbit/types build
pnpm --filter client validate:locales
pnpm --filter client lint:check
pnpm --filter server lint:check
pnpm typecheck:server
pnpm typecheck:client
pnpm --filter client exec vitest run src/stores/__tests__/locale.spec.ts
pnpm --filter server exec vitest run src/modules/user-preferences/user-preferences.service.test.ts

Then verify manually:

• The language picker shows the native label.
• Browser detection selects the intended locale without confusing regional variants.
• Refreshing the application preserves the selected locale.
• <html lang> and <html dir> are correct.
• Number, date, and relative-time formatting use the intended locale.
• Representative desktop and mobile screens handle translated text expansion.
• RTL layout, keyboard navigation, focus states, dialogs, menus, and popovers remain usable when applicable.
• A manual Crowdin export produces the expected filename and passes all PR checks.

Only enable scheduled export for the new language after this manual round trip succeeds.

Crowdin Project Settings

Use the native GitHub integration in Source and translation files mode with only main connected. Do not use Target file bundles mode or automatic feature-branch discovery.

Initial import settings:

• Import existing translations once.
• Allow target translations to match the source.
• Do not continuously import translations from GitHub afterward.
• Keep Push Sources disabled.

Export settings:

• Skip untranslated strings: off.
• Skip untranslated files: off.
• Export only approved translations: off during the initial rollout.

These settings make Crowdin export English source text for untranslated entries instead of empty JSON values, preserving BookOrbit's complete-catalog requirement.

Configure variable mismatches and leading or trailing whitespace as Crowdin QA errors. Keep punctuation and length checks enabled, and include translator instructions for Vue I18n plural branches, the HTML prohibition, and the Unicode em dash prohibition.

Use a daily translation export schedule and manual synchronization before releases. Keep automatic merging disabled.