Conditional Rules

Conditional validation rules control when fields are required based on other field values.

Rules Reference

Rule	Parameters	Example	Error Message
nullable	—	$v->rule('nullable', 'field')	{field} can be null or must be valid
optional	—	$v->rule('optional', 'field')	(always passes)
requiredWith	fields, strict?	$v->rule('requiredWith', 'field', 'other')	{field} is required
requiredWithout	fields, strict?	$v->rule('requiredWithout', 'field', 'other')	{field} is required

Note: Parameters marked with ? are optional.

Behavior Comparison

Rule	Missing Field	Null Value	Empty String
optional	Skips validation	Validates	Skips validation
nullable	Skips validation	Skips validation	Validates

Parameter Details

requiredWith / requiredWithout

Parameter	Type	Default	Description
fields	string|array	—	Field(s) that trigger the requirement
strict	bool	false	false = ANY field, true = ALL fields

Examples:

// Required if ANY field present
$v->rule('requiredWith', 'password', ['username', 'email']);

// Required if ALL fields present (strict mode)
$v->rule('requiredWith', 'suffix', ['first_name', 'last_name'], true);

// Either/or validation
$v->rule('requiredWithout', 'email', 'phone');
$v->rule('requiredWithout', 'phone', 'email');

---

Complete Examples

Valicomb supports two syntax styles: rule-based (map rules to fields) and field-based (map fields to rules).

Field-Based Mapping

use Frostybee\Valicomb\Validator;

$v = new Validator($data);

$v->forFields([
    'email' => [['requiredWithout', 'phone'], 'email'],
    'phone' => [['requiredWithout', 'email'], 'phone'],
    'parent_id' => ['nullable', 'integer'],
    'bio' => ['optional', ['lengthMin', 10], ['lengthMax', 500]],
    'website' => ['optional', 'url'],
    'shipping_street' => [['requiredWith', 'use_different_shipping']],
    'shipping_city' => [['requiredWith', 'use_different_shipping']],
    'shipping_zip' => [['requiredWith', 'use_different_shipping']],
    'card_cvv' => [['requiredWith', 'card_number'], ['length', 3]]
]);

$v->validate();

Rule-Based Array Syntax

use Frostybee\Valicomb\Validator;

$v = new Validator($data);

$v->rules([
    'nullable' => [
        ['parent_id'],
        ['manager_id']
    ],
    'optional' => [
        ['middle_name'],
        ['bio'],
        ['website']
    ],
    'requiredWith' => [
        ['shipping_street', 'use_different_shipping'],
        ['shipping_city', 'use_different_shipping'],
        ['shipping_zip', 'use_different_shipping'],
        ['card_cvv', 'card_number']
    ],
    'requiredWithout' => [
        ['email', 'phone'],
        ['phone', 'email']
    ]
]);

$v->validate();