respect-validation/docs/validators/UndefOr.md

UndefOr

• UndefOr(Validator $validator)

Validates the input using a defined validator when the input is not null or an empty string ('').

This validator can be particularly useful when validating form fields.

Usage

v::undefOr(v::alpha())->isValid(''); // true
v::undefOr(v::digit())->isValid(null); // true

v::undefOr(v::alpha())->isValid('username'); // true
v::undefOr(v::alpha())->isValid('has1number'); // false

Prefix

For convenience, you can use the undefOr as a prefix to any validator:

v::undefOrEmail()->isValid('not an email'); // false
v::undefOrBetween(1, 3)->isValid(2); // true

Templates

UndefOr::TEMPLATE_STANDARD

Mode	Template
default	or must be undefined
inverted	and must not be undefined

The templates from this validator serve as message suffixes:

v::undefOr(v::alpha())->assert('has1number');
// "has1number" must contain only letters (a-z) or must be undefined

v::not(v::undefOr(v::alpha()))->assert("alpha");
// "alpha" must not contain letters (a-z) and must not be undefined

Template placeholders

Placeholder	Description
subject	The validated input or the custom validator name (if specified).

Categorization

• Nesting

Changelog

Version	Description
3.0.0	Renamed to UndefOr
1.0.0	Created as Optional

---

See also:

• Blank
• Falsy
• NullOr
• NullType
• Spaced
• Undef