Internationalization

v0.7.0 brings first-class internationalization to Tidos. Powered by Mozilla's Fluent localization system, you can now translate any string in any component with a single macro call.

Enabling i18n

Add the i18n feature flag to your Cargo.toml:

1[dependencies]
2tidos = { version = "0.7.0", features = ["rocket", "i18n"] }

Create a Tidos.toml in your project root to configure the locale directory and default language:

1[default]
2resource_location = "translations"
3default_locale = "en-US"
4resources = ["common.ftl"]

Then call enable_i18n! once at the top of main.rs to load the translation files at startup:

1use tidos::i18n::enable_i18n;
2
3enable_i18n!();
4
5#[rocket::main]
6async fn main() { /* ... */ }

Translating strings with i18n!

Inside any component, import and call i18n! with a Fluent message key:

1use tidos::i18n::i18n;
2
3impl Component for Greeting {
4    fn to_render(&self, page: &mut Page) {
5        view! {
6            <h1>{i18n!("greeting")}</h1>
7        }
8    }
9}

Variables are passed as alternating key-value pairs after the message key:

1// Fluent message with variable:
2// welcome = Welcome back, { $name }!
3
4view! {
5    <p>{i18n!("welcome", "name", &self.username)}</p>
6}

Translation files

Fluent .ftl files live under your resource_location, organised by locale:

1translations/
2  en-US/
3    common.ftl
4  nl-NL/
5    common.ftl

Fluent supports plural forms, gender variants, and other selectors out of the box, so you can handle complex grammatical rules without hand-written conditionals:

1new-messages =
2    { $count ->
3        [one]  You have one new message.
4       *[other] You have { $count } new messages.
5    }

Locale routing with Lang

Add a Lang parameter to your route to accept a locale prefix in the URL. Tidos picks up the active locale automatically inside page!:

1use tidos::i18n::Lang;
2
3#[get("/<lang>/dashboard")]
4pub fn dashboard(lang: Lang) -> Page {
5    page! {
6        <main>
7            <h1>{i18n!("dashboard-title")}</h1>
8        </main>
9    }
10}

The lang parameter doubles as a Rocket request guard and as the active locale context for all i18n! calls on that page.

Upgrading

No breaking changes for existing Tidos users. The i18n feature is entirely opt-in:

1[dependencies]
2tidos = "0.7.0"  # existing usage unaffected