attac-t Skill: Craft DTO
"Type safety isn't a luxury; it's requirements documentation."
Before You Start
- Read the docs: spatie.be/docs/laravel-data/v4
- Explore the namespace:
vendor/spatie/laravel-data/srcto avoid hallucination.
The Standard
- Two Types:
Create{Model}{Suffix}(input) vs{Model}{Suffix}(output/representation). - The Repo Declares
{Suffix}:DTOorData— whichever already dominates. Consistency with the codebase beats any plugin preference. - Upsert Pairs 1:1:
Upsert{Model}{Suffix}↔Upsert{Model}Action. Matching names, oneOptionalid. - Native Collection: Prefer
CollectionoverDataCollection. Use$data->all(). - Lazy Relations:
#[AutoWhenLoadedLazy]for conditional relationship inclusion. - Immutable: Mutate via
->with(), never direct assignment.
The Anti-Patterns
| ❌ Don't | ✅ Do | Why |
|---|---|---|
DataCollection |
Native Collection |
v4 preferred for basic nesting. |
#[Required] on a typed property |
Non-nullable type, no default | v4 derives required-ness from the type. |
$dto->except('id')->toArray() |
$dto->all() |
Cleaner. Handle Optional in action. |
Omit #[AutoWhenLoadedLazy] |
Always use on relations | Avoids triggering lazy loads. |
#[WithCast] on output DTO |
Only on request DTOs | Casts are for input direction only. |
| Guess API | Read docs + namespace | Avoid hallucination. |
| Direct mutation | ->with() |
Immutability. |
Real-World Examples
See examples/.