# When

- `When(Rule $if, Rule $then)`
- `When(Rule $if, Rule $then, Rule $else)`

A ternary validator that accepts three parameters.

When the `$if` validates, returns validation for `$then`.
When the `$if` doesn't validate, returns validation for `$else`, if defined.

```php
v::when(v::intVal(), v::positive(), v::notEmpty())->isValid(1); // true
v::when(v::intVal(), v::positive(), v::notEmpty())->isValid('not empty'); // true

v::when(v::intVal(), v::positive(), v::notEmpty())->isValid(-1); // false
v::when(v::intVal(), v::positive(), v::notEmpty())->isValid(''); // false
```

In the sample above, if `$input` is an integer, then it must be positive.
If `$input` is not an integer, then it must not be empty.
When `$else` is not defined use [AlwaysInvalid](AlwaysInvalid.md)

## Templates

## Template placeholders

| Placeholder | Description                                                      |
|-------------|------------------------------------------------------------------|
| `name`      | The validated input or the custom validator name (if specified). |

## Categorization

- Conditions
- Nesting

## Changelog

| Version | Description                    |
|--------:|--------------------------------|
|   0.8.0 | Allow to use rule without else |
|   0.3.9 | Created                        |

***
See also:

- [AllOf](AllOf.md)
- [AlwaysInvalid](AlwaysInvalid.md)
- [AnyOf](AnyOf.md)
- [Circuit](Circuit.md)
- [NoneOf](NoneOf.md)
- [OneOf](OneOf.md)