Attributes Overview

All behaviour in Simple Data Objects is declared via PHP attributes on constructor parameters (or on the class itself for #[TransformKeys]).

Attribute	Target	Purpose
#[Cast]	Parameter	Apply a type cast during hydration and serialization
#[Rules]	Parameter	Laravel validation rules
#[Flatten]	Parameter	Inline nested DTO fields into the parent array
#[Hidden]	Parameter	Exclude from toArray() / JSON output
#[IgnoreIfNull]	Parameter	Omit from output when value is null
#[MapPropertyName]	Parameter	Map a different input key to this property
#[TransformKeys]	Class	Transform all input keys at the class level
#[DataCollection]	Parameter	Declare a typed collection property