Validation Rules

Available Validation Rules

Laravel Countries provides three validation rules for validating country-related data in your forms:

ValidCountryCode Rule

Validates country codes in ISO 3166-1 format (2-letter or 3-letter):

use Webpatser\Countries\Rules\ValidCountryCode;
 
// In a Form Request
public function rules()
{
    return [
        'country' => ['required', new ValidCountryCode()],          // Any format
        'country_2' => ['required', new ValidCountryCode('iso_3166_2')], // 2-letter only
        'country_3' => ['required', new ValidCountryCode('iso_3166_3')], // 3-letter only
    ];
}
 
// In a Controller
$request->validate([
    'shipping_country' => ['required', new ValidCountryCode('iso_3166_2')],
    'billing_country' => ['required', new ValidCountryCode('iso_3166_2')],
]);

ValidCurrencyCode Rule

Validates currency codes in ISO 4217 format:

use Webpatser\Countries\Rules\ValidCurrencyCode;
 
// Basic usage
$request->validate([
    'currency' => ['required', new ValidCurrencyCode()],
    'price_currency' => ['nullable', new ValidCurrencyCode()],
]);
 
// In a Form Request
public function rules()
{
    return [
        'default_currency' => ['required', new ValidCurrencyCode()],
        'accepted_currencies' => ['array'],
        'accepted_currencies.*' => [new ValidCurrencyCode()],
    ];
}

Common Valid Currency Codes

ValidRegion Rule

Validates geographical region names:

use Webpatser\Countries\Rules\ValidRegion;
 
// Basic usage
$request->validate([
    'target_region' => ['required', new ValidRegion()],
    'excluded_regions' => ['array'],
    'excluded_regions.*' => [new ValidRegion()],
]);
 
// Example form processing
public function updateMarketingSettings(Request $request)
{
    $validated = $request->validate([
        'primary_market' => ['required', new ValidRegion()],
        'secondary_markets' => ['array'],
        'secondary_markets.*' => [new ValidRegion()],
    ]);
 
    // Process the validated data...
}

Valid Regions

Complete Form Request Example

Here's a comprehensive example of using all validation rules in a Form Request:

namespace App\Http\Requests;
 
use Illuminate\Foundation\Http\FormRequest;
use Webpatser\Countries\Rules\ValidCountryCode;
use Webpatser\Countries\Rules\ValidCurrencyCode;
use Webpatser\Countries\Rules\ValidRegion;
 
class UserProfileRequest extends FormRequest
{
    public function authorize()
    {
        return true;
    }
 
    public function rules()
    {
        return [
            'name' => ['required', 'string', 'max:255'],
            'email' => ['required', 'email', 'unique:users'],
            'country_code' => ['required', new ValidCountryCode('iso_3166_2')],
            'preferred_currency' => ['nullable', new ValidCurrencyCode()],
            'target_regions' => ['array'],
            'target_regions.*' => [new ValidRegion()],
        ];
    }
 
    public function messages()
    {
        return [
            'country_code.required' => 'Please select your country.',
            'preferred_currency.valid_currency_code' => 'Please enter a valid currency code (e.g., USD, EUR).',
            'target_regions.*.valid_region' => 'Please select valid regions only.',
        ];
    }
}

Custom Error Messages

You can customize validation error messages in several ways:

In Form Requests

public function messages()
{
    return [
        'country_code.valid_country_code' => 'The selected country is invalid.',
        'currency.valid_currency_code' => 'Please enter a valid currency code.',
        'region.valid_region' => 'The selected region is not supported.',
    ];
}
 
public function attributes()
{
    return [
        'country_code' => 'country',
        'preferred_currency' => 'currency',
    ];
}

Using Lang Files

Add custom messages to resources/lang/en/validation.php:

// resources/lang/en/validation.php
'custom' => [
    'country_code' => [
        'valid_country_code' => 'Please select a valid country from the list.',
    ],
    'billing_currency' => [
        'valid_currency_code' => 'The billing currency must be a valid ISO currency code.',
    ],
],

Advanced Usage

Conditional Validation

public function rules()
{
    return [
        'country_code' => ['required', new ValidCountryCode('iso_3166_2')],
        'state' => [
            'required_if:country_code,US',
            'string'
        ],
        'currency' => [
            Rule::requiredIf($this->input('country_code') !== 'US'),
            new ValidCurrencyCode()
        ],
    ];
}

Array Validation

// Validate multiple countries
$request->validate([
    'supported_countries' => ['required', 'array', 'min:1'],
    'supported_countries.*' => [new ValidCountryCode('iso_3166_2')],
    'supported_currencies' => ['required', 'array'],
    'supported_currencies.*' => [new ValidCurrencyCode()],
]);

API Validation

// API endpoint validation
Route::post('/api/orders', function (Request $request) {
    $validated = $request->validate([
        'shipping_country' => ['required', new ValidCountryCode('iso_3166_2')],
        'billing_country' => ['required', new ValidCountryCode('iso_3166_2')],
        'currency' => ['required', new ValidCurrencyCode()],
        'target_regions' => ['array'],
        'target_regions.*' => [new ValidRegion()],
    ]);
 
    // Process order...
    return response()->json(['status' => 'success']);
});

Performance Considerations

Caching Validation Results

For high-traffic applications, consider caching validation data:

// In your service provider
use Illuminate\Support\Facades\Cache;
use Webpatser\Countries\Models\Country;
 
public function boot()
{
    // Cache valid country codes for 24 hours
    Cache::remember('valid_country_codes', 86400, function () {
        return Country::pluck('iso_3166_2')->toArray();
    });
}