ferro-lang

Localization crate for the Ferro web framework.

Provides JSON-based translation loading with per-request locale detection, string interpolation, and pluralization. Integrates directly with Ferro's request lifecycle via middleware.

Features

• JSON translation files — one file per locale (en.json, fr.json, etc.)
• Per-request locale detection — Accept-Language header, query param (?lang=fr), or session value
• String interpolation — :name syntax for named placeholders
• Pluralization — locale-aware plural forms (one | other rules)
• Validation message localization — translate Ferro validation error messages automatically
• Middleware — LocaleMiddleware sets the active locale on every request

Usage

use ferro_lang::{Lang, LocaleMiddleware};

// Load translations at startup
let lang = Lang::from_dir("lang/")   // loads en.json, fr.json, etc.
    .default_locale("en")
    .build()?;

// In middleware or handler
let greeting = lang.t("messages.welcome", &[("name", "World")]);
// en.json: { "messages": { "welcome": "Hello, :name!" } }
// => "Hello, World!"

// Pluralization
let message = lang.t_count("items.count", count, &[]);
// en.json: { "items": { "count": "one item | :count items" } }
// => "1 item" or "5 items"

Documentation

Full documentation at docs.ferro-rs.dev.

License

MIT