Data validation Library

Click here to read russian version.

This library is created as an educational project on Hexlet platform. See the description of the project (rus).

It is a data validator that can check data to be of certain type with some other checking methods defined.

Usage and description

General notes

First you need to create an object Validator().

$v = new \Hexlet\Validator\Validator();

Checking is performed first by stating the type for validation, then by calling methods specifying a certain types of checking needed to be performed (these are not obligatory) and then by passing in data using isValid($data) method.

$schema = $v->string()->contains('hey')->isValid('hey there');

Methods defined in this library for different data type validation:

string() - for string type data;

number() - for integer type data;

array() - for array type data;

addValidator(string $type, string $name, callable $fn) - add custom validator function $fn to a $type validator;

Calling same method creates different schema for validation (no need to create new Validator() objects for every schema).

$v = new \Hexlet\Validator\Validator();

$schema = $v->string();
$schema2 = $v->string(); // $schema != $schema2

Note

All called methods listed below for different data types are stackable. For example calling positive and range methods for number type will exclude negative numbers from the range:

$schema->number()->positive()->range(-5, 5);

$schema->isValid(-3); // false
$schema->isValid(5); // true

String validation methods

required() method makes data not nullable. Call this method before passing in data.

$v = new \Hexlet\Validator\Validator();
$schema = $v->string();
$schema->isValid(null); // true

$schema->required();

$schema->isValid(null); // false
$schema->isValid(''); // false

contains($string) - checks for $string to be present in a $data passed in with isValid($data) method:

$schema->contains('what')->isValid('what does the fox say'); // true
$schema->contains('whatthe')->isValid('what does the fox say'); // false

minLength($num) - checks $data to be at least $num characters long:

$v->string()->minLength(5)->isValid('Hexlet'); // true

Number validation methods

Works with integers.

required() method makes data not nullable. 0 (zero) is a number too, required() will return true.

$v = new \Hexlet\Validator\Validator();

$schema = $v->number();
$schema->isValid(null); // true
$schema->required();
$schema->isValid(null); // false
$schema->isValid(0); // true

positive() - checks if number is above 0. (0 included)

$schema->positive()->isValid(10); // true

range($left, $right) - specify range in which the checked number should be located. Boundaries are included.

$schema->range(-5, 5);
$schema->isValid(5); // true

Array validation methods

required() method makes data not nullable. Empty array is considered a valid data, returns true after check

$schema = $v->array();
$schema->isValid(null); // true

$schema = $schema->required();

$schema->isValid([]); // true
$schema->isValid(['hexlet']); // true

sizeOf($num) - checks if the length of an array is exactly $num

$schema->sizeof(2);

$schema->isValid(['hexlet']); // false
$schema->isValid(['hexlet', 'code-basics']); // true

shape() - with this method you can specify what data type and checks should be performed on data under the certain key-values of an array:

$schema->shape([
    'name' => $v->string()->required(),
    'age' => $v->number()->positive(),
]);

$schema->isValid(['name' => 'kolya', 'age' => 100]); // true
$schema->isValid(['name' => 'maya', 'age' => null]); // true
$schema->isValid(['name' => '', 'age' => null]); // false
$schema->isValid(['name' => 'ada', 'age' => -5]); // false

Create custom validation rules

addValidator(string $type, string $name, callable $fn) method can add a custom validator function $fn to a $type validator. Types are passed in as a string and 3 types (string, number, array) are supported.

$v = new \Hexlet\Validator\Validator();

$fn = fn($value, $start) => str_starts_with($value, $start);
$v->addValidator('string', 'startWith', $fn);

test() method should be called to initiate data validation by the rules added.

$schema = $v->string()->test('startWith', 'H');
$schema->isValid('exlet'); // false
$schema->isValid('Hexlet'); // true

Another example:

$fn = fn($value, $min) => $value >= $min;
$v->addValidator('number', 'min', $fn);

$schema = $v->number()->test('min', 5);
$schema->isValid(4); // false
$schema->isValid(6); // true

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