Field Attribute

The #[Field] attribute configures how each property is processed from HTTP requests.

Parameters

#[Field(
    rules: ?string = null,
    cast: ?string = null,
    mapFrom: ?string = null,
    preProcess: ?string = null,
    postProcess: ?string = null,
    group: ?string = null,
    generator: ?string = null,
    generatorOptions: array = [],
    exclude: bool = false,
)]

Parameter	Type	Description
rules	?string	Validation rules string
cast	?string	Explicit type casting
mapFrom	?string	Dot-notation path to source data
preProcess	?string	Function/class to run before validation
postProcess	?string	Function/class to run after validation
group	?string	Group name for bulk extraction
generator	?string	Class to generate field value
generatorOptions	array	Options passed to generator
exclude	bool	Exclude from toArray() output

---

rules

Validation rules as a pipe-separated string:

#[Field(rules: 'required|string|max:255')]
public string $name;

#[Field(rules: 'required|email|unique:users,email')]
public string $email;

#[Field(rules: 'nullable|integer|min:0|max:100')]
public ?int $quantity = null;

See Validation for available rules.

---

cast

Explicitly cast the value to a type:

#[Field(cast: 'int')]
public int $count;

#[Field(cast: 'datetime:Y-m-d')]
public DateTime $birthDate;

#[Field(cast: CustomMoneyCaster::class)]
public Money $price;

See Type Casting for details.

---

mapFrom

Map from nested input data using dot notation:

// Request: {"user": {"profile": {"age": 30}}}

#[Field(mapFrom: 'user.profile.age')]
public int $userAge; // 30

---

preProcess / postProcess

Transform data before or after validation:

// Global function
#[Field(preProcess: 'trim')]
public string $name;

// Processor class
#[Field(postProcess: SlugProcessor::class)]
public string $slug;

// Static method on Request class
#[Field(postProcess: 'normalizePhone')]
public string $phone;

public static function normalizePhone(string $value): string
{
    return preg_replace('/[^0-9+]/', '', $value);
}

See Processors for details.

---

group

Assign fields to a named group for bulk extraction:

#[Field(group: 'filters')]
public ?string $search = null;

#[Field(group: 'filters')]
public ?string $status = null;

#[Field(group: 'pagination')]
public int $page = 1;

// Extract all filter fields
$filters = $dto->group('filters');
// ['search' => '...', 'status' => '...']

See Field Grouping for details.

---

generator

Auto-generate field values:

#[Field(generator: UuidGenerator::class)]
public string $id;

#[Field(
    generator: SequenceGenerator::class,
    generatorOptions: ['table' => 'orders']
)]
public int $orderNumber;

See Generators for details.

---

exclude

Exclude field from toArray() output:

#[Field(rules: 'in:pending,processing', exclude: true)]
public string $internalStatus = 'pending';

// $dto->toArray() will NOT include 'internalStatus'
// But $dto->internalStatus is still accessible

---

Optional Attribute

The #[Field] attribute is optional. Properties without it are still processed but with defaults:

final class UserRequest extends Request
{
    #[Field(rules: 'required|string')]
    public string $name;           // With validation

    public ?string $email = null;  // No validation, just populated
    public int $age = 18;          // No validation, has default
}

---

Complete Example

final class CreateOrderRequest extends Request
{
    #[Field(generator: UuidGenerator::class)]
    public string $id;

    #[Field(rules: 'required|integer|exists:users,id', mapFrom: 'customer.id')]
    public int $customerId;

    #[Field(rules: 'required|array|min:1')]
    public array $items;

    #[Field(rules: 'nullable|string|max:500', preProcess: 'trim')]
    public ?string $notes = null;

    #[Field(rules: 'in:pending,confirmed', exclude: true)]
    public string $status = 'pending';

    #[Field(cast: 'datetime:Y-m-d', group: 'meta')]
    public ?DateTime $deliveryDate = null;

    #[Field(group: 'meta')]
    public ?string $couponCode = null;
}