Localization

English strings in code and templates are the catalog keys. A .po file per language translates them.

Write translatable text

use laterite_core::{t, tn};

let msg = t!("Your changes were saved.");
let greeting = t!("Welcome back, {name}.").arg("name", user.name.clone());
let label = tn!("{n} item", "{n} items", count).arg("n", count);

Where	Call
Rust	`t!("...")`; `tn!("one", "many", n)` for plurals. Both build a `Text`, localized at render.
Template	`shell.t("...")`; `shell.tf(...)` with numeric placeholders.
Descriptor labels	Already `Text`, localized where they render.

A placeholder such as {name} appears unchanged in every translation.

Manage catalogs

crates/admin/lang/
  messages.pot     # generated template, every source string
  de.po            # a German translation

lat i18n extract          # regenerate every messages.pot
lat i18n update de        # create or refresh de.po from the template
lat i18n status           # per-locale coverage
lat i18n check            # fail if any messages.pot is stale; run in CI

A translator fills in msgstr:

#: templates/login.html
msgid "Admin panel"
msgstr "Verwaltung"

Ship a language from a module

impl Module for AcmeModule {
    fn catalogs(&self) -> &'static [(&'static str, &'static str)] {
        &[
            ("de", include_str!("../lang/de.po")),
            ("fr", include_str!("../lang/fr.po")),
        ]
    }
}

A malformed catalog, or one whose placeholders differ from the source, fails the boot.

How a language is chosen

The operator’s preference, from Preferences.
The browser’s Accept-Language.
backend.locale.
English.

Only a language with a loaded catalog is offered or chosen. Plural rules cover one and other. Month and day names follow a locale that carries a territory, de_DE.

Preview coverage

Set the locale to xx, or send Accept-Language: xx: every translated string renders bracketed and accented, [Ṡäṽé]. Plain text is a string that bypassed translation.