Languages and translations

#Choosing a language

Flowplan follows your browser's language; languages Flowplan does not know show English. Under Settings → Appearance & language → Language you pick a language (with its flag) from the list – it then applies on all devices, also to e-mails and push notifications; Automatic (follows the browser) undoes the choice. On the sign-in page the small button at the bottom right (e.g. 🇬🇧 EN) opens a menu with all languages.

Dates, times and numbers follow the language (French: fr-FR, e.g. “15 oct. 2026” and “2 400,5”). Calculations in notes use the decimal comma in French as well.

What you create yourself – pages, databases, properties – stays in the language it was made in. Templates and example content exist in German and English; French accounts get the English ones.

#How translation works

German and English sit side by side in the code. Every further language is a catalogue in the app's locales/ folder that maps the English text to its translation:

{
  "Sign in": "Se connecter",
  "{0} commented on “{1}”": "{0} a commenté « {1} »"
}

• locales/en.json lists every text of the app (more than 3,500) and is the source for translation tools. It is generated, not edited by hand.
• {0}, {1} … stand for values such as names or numbers. They have to appear in the translation; their order may change.
• An empty or missing entry shows the English text – so a language can grow step by step, and new texts in the app never break anything.

#Adding a language

1. Create the catalogue, e.g. for Italian:

   npm run i18n -- --add it

   This creates locales/it.json with every text and empty translations.

2. Translate – by hand or with a tool such as Weblate, Crowdin, POEditor or Lokalise (format “JSON key-value” or “i18next JSON”, source file locales/en.json). Machine translation (e.g. DeepL) works as a draft; please keep placeholders and HTML tags unchanged.

3. Register the language: in lib/i18n.ts under LANGUAGES with its name and date format (it: { name: "Italiano", tag: "it-IT" }), and import the catalogue in lib/i18n-catalogs.ts.

4. Check:

   npm run i18n -- --check            # progress and wrong placeholders
   npm run i18n -- --check --missing  # what is still missing, with the place in the code

The language then appears in the choice on the sign-in page and in the profile, and browsers in that language get it automatically.

#Keeping catalogues up to date

After texts change in the code, npm run i18n collects all texts again: new ones are added empty to every catalogue, unused ones drop out, existing translations stay. The tests only report missing translations; wrong placeholders make them fail.

In the code, texts are t("Deutsch", "English") in components, tr() outside of them and ct() for content the server creates. Tables of text pairs get a marker so npm run i18n finds them, e.g. // i18n-table: 1 for [German, English] pairs.

#Text recognition

Text recognition for scanned PDFs and images is separate: it reads German and English, and French with FLOWPLAN_OCR_LANGS=fra,eng (see Configuration).