Struct I18nManager 

pub struct I18nManager {
    pub current_locale: LanguageIdentifier,
    /* private fields */
}

Fields

current_locale: LanguageIdentifier

Implementations

impl I18nManager

pub fn register_widget_messages()

Register shared widget labels in every bundled language without replacing an application’s catalogs or its selected language. A host (the shell, an app) calls this once per thread so every toolkit widget it draws follows the desktop’s language; calling it again is free.

pub fn init(locale: &str)

pub fn install( source_locale: &str, active_locale: &str, catalogs: &[(&str, &str)], ) -> Result<(), I18nError>

Atomically install every bundled Fluent catalog and select an explicit active locale. Lookup falls back from the active language to source_locale, then to the key itself.

Errors

Returns a locale/resource/duplicate error without replacing the live catalog.

pub fn install_system( source_locale: &str, catalogs: &[(&str, &str)], ) -> Result<(), I18nError>

Install catalogs using the process/user locale (LC_ALL, LC_MESSAGES, LANGUAGE, then LANG) with source-locale fallback.

Errors

Returns any error documented by Self::install.

pub fn add_resource(locale: &str, ftl_source: String)

pub fn set_locale(locale: &str)

pub fn set_locale_or_source(locale: &str)

Select locale, or the source locale when locale is C, POSIX or does not parse — where Self::set_locale would keep the current selection.

pub fn has_message(key: &str) -> bool

Whether a catalogue installed on this thread defines key. The shared toolkit fallback does not count, and pseudo-localisation plays no part.

pub fn current_locale() -> String

pub fn revision() -> u64

Monotonic retained-widget invalidation token. It changes only when a catalog or active locale changes.

pub fn set_pseudo_locale(mode: PseudoLocale)

Enable or disable pseudo-localized output. The retained-widget revision changes on an effective transition so text is reshaped and layout can be recomputed without restarting the application.

pub fn pseudo_locale() -> PseudoLocale

pub fn lookup(key: &str, args: Option<&FluentArgs<'_>>) -> String

Resolve key in the active locale.

Bundles are consulted in order: the active locale’s own catalogue, then a language-only catalogue of the same language, then other regions of that language in registration order, then the source catalogue — formatted under the active locale’s plural rules, so a count follows the user’s grammar even in fallback copy (a language without CLDR rules formats with English ones, as before) — then the shared toolkit catalogue. The first bundle that formats the message without errors wins; if every candidate reports errors the first best-effort rendering is returned, and a key no bundle defines resolves to itself.

pub fn lookup_plain(key: &str) -> String

Resolve a message without variables. This function-shaped form is convenient in iterator adapters such as Option::map.

pub fn format(key: &str, args: &[(&str, ArgValue)]) -> String

Resolve key, interpolating named variables into the message’s placeables (e.g. counter = Count is { $count } with count=5 yields Count is 5).

Degrades gracefully: a key with no loaded resource falls back to the key itself, and a placeable whose variable is missing is left as the formatter’s best-effort rendering rather than panicking. Passing an empty slice is equivalent to a plain lookup.