Mapping Attributes

Reference for property mapping attributes.

Introduction

SimpleDTO provides 2 mapping attributes:

• #[MapFrom(string $source)] - Map from different input key
• #[MapTo(string $target)] - Map to different output key

MapFrom Attribute

Map input data from a different key:

use Event4u\DataHelpers\SimpleDTO\Attributes\MapFrom;

#[MapFrom('full_name')]
public readonly string $name;

#[MapFrom('email_address')]
public readonly string $email;

Nested Path Mapping

#[MapFrom('contact.email')]
public readonly string $email;

#[MapFrom('address.city.name')]
public readonly string $city;

Multiple Sources (Fallback)

#[MapFrom(['user.email', 'user.mail', 'email'])]
public readonly string $email;

MapTo Attribute

Map output data to a different key:

use Event4u\DataHelpers\SimpleDTO\Attributes\MapTo;

#[MapTo('full_name')]
public readonly string $name;

#[MapTo('email_address')]
public readonly string $email;

Nested Output

#[MapTo('user.profile.email')]
public readonly string $email;
// Output: ['user' => ['profile' => ['email' => '...']]]

Bidirectional Mapping

#[MapFrom('user_name'), MapTo('user_name')]
public readonly string $userName;

Real-World Examples

API Response Mapping

class UserDTO extends SimpleDTO
{
    public function __construct(
        #[MapFrom('user_id')]
        public readonly int $id,

        #[MapFrom('user_name')]
        public readonly string $name,

        #[MapFrom('user_email')]
        public readonly string $email,
    ) {}
}

Database Column Mapping

class OrderDTO extends SimpleDTO
{
    public function __construct(
        #[MapFrom('order_id')]
        public readonly int $id,

        #[MapFrom('customer_name')]
        public readonly string $customerName,
    ) {}
}

Combining with Other Attributes

// MapFrom + Validation
#[MapFrom('user_email'), Required, Email]
public readonly string $email;

// MapFrom + Cast
#[MapFrom('created_at'), Cast(DateTimeCast::class)]
public readonly Carbon $createdAt;

Best Practices

Use Descriptive Property Names

// ✅ Good
#[MapFrom('usr_nm')]
public readonly string $userName;

// ❌ Bad
#[MapFrom('usr_nm')]
public readonly string $usrNm;

See Also

• Property Mapping - Detailed guide
• Validation Attributes - Validation reference