Custom Formats

A format can be defined in two ways:

• as a callable, with the following signature:

  function (mixed $value): bool
  

• as class implementing Opis\JsonSchema\Format interface. The validate method has the following signature:

  public function validate(mixed $value): bool
  

Using formats

You should register your formats before you validate any schema. When you register a format you must specify:

• JSON data type (number, integer, string, array, object)
• name: the name you will use in your schemas
• the format

<?php

use Opis\JsonSchema\Validator;
use Opis\JsonSchema\Resolvers\FormatResolver;

$validator = new Validator();

/** @var FormatResolver $formats */
$formats = $validator->parser()->getFormatResolver();

$isPrime = function (int $value): bool {
    if ($value < 2) {
        return false;
    }
    
    if ($value == 2) {
        return true;
    }
    
    $max = floor(sqrt($value)) + 1;
    
    for ($i = 3; $i < $max; $i += 2) {
        if ($value % $i == 0) {
            return false;
        }
    }
    
    return true;
};

// Register our prime number format
$formats->registerCallable("integer", "prime", $isPrime);

Here is an example that uses our prime number format

{
  "type": "integer",
  "format": "prime"
}

This schema validates 5, but does not validate 9 (3 * 3).