Translations

Vizia uses Fluent (.ftl) files for localized strings. Load translation files with cx.add_translation() during app startup.

use vizia::prelude::*;

fn main() -> Result<(), ApplicationError> {
    Application::new(|cx| {
        cx.add_translation(
            "en-US".parse().unwrap(),
            include_str!("resources/translations/en-US/hello.ftl").to_owned(),
        )
        .expect("Failed to add en-US translation");

        cx.add_translation(
            "fr".parse().unwrap(),
            include_str!("resources/translations/fr/hello.ftl").to_owned(),
        )
        .expect("Failed to add fr translation");

        Label::new(cx, Localized::new("hello-world"));
    })
    .run()
}

Use a locale-based folder structure:

.
├── Cargo.toml
└── src
    ├── resources
    │   └── translations
    │       ├── en-US
    │       │   └── counter.ftl
    │       └── es
    │           └── counter.ftl
    └── main.rs

Multiple files per locale

You can register multiple Fluent files for the same locale. Vizia merges them into one bundle.

cx.add_translation(
    "en-US".parse().unwrap(),
    include_str!("resources/translations/en-US/common.ftl").to_owned(),
)
.expect("Failed to add common strings");

cx.add_translation(
    "en-US".parse().unwrap(),
    include_str!("resources/translations/en-US/settings.ftl").to_owned(),
)
.expect("Failed to add settings strings");

Splitting translations by feature can make large applications easier to maintain.

Locale negotiation and fallback

Vizia uses the system locale by default, then negotiates to the best available loaded locale. If a key is still missing, it falls back per-message to the default bundle.

This means you can load a partial locale and keep the app functional while you complete translations.

Changing locale at runtime

cx.emit(EnvironmentEvent::SetLocale("fr".parse().unwrap()));

Translation diagnostics

Missing messages, missing attributes, and Fluent formatting issues are reported through the log backend at warn level.

To make these visible while developing, configure a logger for your app (for example env_logger).