# 🌐 Localization Setup
Valida natively integrates with [`rust-i18n`](https://github.com/longbridge/rust-i18n), enabling rich multi-language support without requiring external libraries like Fluent. You can use built-in language packs or define your own translations for custom error keys.
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## ✨ Supported Languages
By default, Valida supports:
uk, en, de, es, pl, hi, fr, pt, ja
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These are bundled with localized strings for built-in rules like `min_length`, `email`, `max`, `required`, etc.
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## 🧩 Setup Guide
### 1. Add dependencies
```toml
[dependencies]
rust-i18n = { version = "" }
valida = { version = "" }
```
### 2. Enable rust-i18n in your main module
```rust
use rust_i18n::t;
rust_i18n::i18n!("locales"); // This loads all .yml files in /locales
```
# 🗂 Structure for Localization Files
Your project layout should include a folder:
```toml
your_project/
└── locales/
├── en.yml
├── uk.yml
└── ...
```
Each YAML file contains key-value translations:
```yaml
# locales/en.yml
validator.min_length: Minimum length is %{min} characters.
age.too_young: Must be at least 18 years old.
```
You can override any built-in key or add your own.
---
# 🧠 Using Error Keys in Custom Rules
```rust
ValidationError::new("age.too_young")
```
Or with parameters:
```rust
ValidationError::new_with_params(
"validator.max_length",
HashMap::from([("max".to_string(), "10".to_string())])
)
```
Which resolves to:
```yaml
validator.max_length: Value must not exceed %{max} characters.
```
---
# 🧪 Runtime Localization
You can change language dynamically:
```rust
println!("{}", errors.pretty_print("uk"));
```
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# 📦 Overriding Messages
Simply redefine the key in your own YAML file. Valida will pick up your version if present in the selected locale.
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# 🧠 Best Practices
* Use lowercase dotted keys: `validator.min_length`, `age.too_young`
* Define all custom rule keys in your `locales/*.yml`
* Keep parameter keys (`%{param}`) intuitive and consistent