respect-validation/docs/validators/Factory.md
Henrique Moody b701fac656
Create ShortCircuit validator and ShortCircuitable interface
This commit introduces a mechanism for validators to return early once
the validation outcome is determined, rather than evaluating all child
validators.

The ShortCircuit validator evaluates validators sequentially and stops
at the first failure, similar to how PHP's && operator works. This is
useful when later validators depend on earlier ones passing, or when
you want only the first error message.

The ShortCircuitCapable interface allows composite validators (AllOf,
AnyOf, OneOf, NoneOf, Each, All) to implement their own short-circuit
logic.

Why "ShortCircuit" instead of "FailFast":

The name "FailFast" was initially considered but proved misleading.
While AllOf stops on failure (fail fast), AnyOf stops on success
(succeed fast), and OneOf stops on the second success. The common
behavior is not about failing quickly, but about returning as soon as
the outcome is determined—which is exactly what short-circuit
evaluation means. This terminology is familiar to developers from
boolean operators (&& and ||), making the behavior immediately
understandable.

Co-authored-by: Alexandre Gomes Gaigalas <alganet@gmail.com>
Assisted-by: Claude Code (Opus 4.5)
2026-02-05 17:32:42 +01:00

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# Factory
- `Factory(callable(mixed): Validator $factory)`
Validates the input using a validator that is created from a callback.
```php
v::factory(static fn($input) => v::boolVal())->assert(true);
// Validation passes successfully
```
This validator is particularly useful when creating validators that rely on the input. A good example is validating whether a
`confirmation` field matches the `password` field when processing data from a form.
```php
v::key('confirmation', v::equals($_POST['password'] ?? null))->assert($_POST);
// → `.confirmation` must be present
```
The issue with the code is that its hard to reuse because youre relying upon the input itself (`$_POST`). That means
you can create a chain of validators and use it everywhere.
The `factory()` validator makes this job much simpler and more elegantly:
```php
v::factory(static fn($input) => v::key('confirmation', v::equals($input['password'] ?? null)))->assert($_POST);
// → `.confirmation` must be present
```
The code above is similar to the first example, but the biggest difference is that the creation of the validator doesn't rely
on the input itself (`$_POST`), but it will use any input thats given to the validator
## Templates
## Template placeholders
| Placeholder | Description |
| ----------- | ---------------------------------------------------------------- |
| `subject` | The validated input or the custom validator name (if specified). |
## Categorization
- Callables
- Nesting
## Changelog
| Version | Description |
| ------: | :---------------------- |
| 3.0.0 | Created from `KeyValue` |
## See Also
- [After](After.md)
- [CallableType](CallableType.md)
- [ShortCircuit](ShortCircuit.md)