Creating a Rule Inferrer

Build custom rule inferrers to automatically infer validation rules for data properties

Rule inferrers automatically generate validation rules for properties within a data object.

RuleInferrer Interface

Implement the RuleInferrer interface:

interface RuleInferrer
{
    public function handle(DataProperty $property, PropertyRules $rules, ValidationContext $context): PropertyRules;
}

Parameters

• property - DataProperty object representing the property (read more)
• rules - PropertyRules collection of previously inferred rules
• context - ValidationContext containing:
  • payload - Current payload for the data object being validated
  • fullPayload - Full payload being validated
  • validationPath - Path from full payload to current payload

Working with PropertyRules

Adding Rules

$rules->add(new Min(42));

Automatic Rule Replacement

When adding a rule of the same type, the previous version is removed:

$rules->add(new Min(42));
$rules->add(new Min(314)); 

$rules->all(); // [new Min(314)]

Adding String Rules

$rules->add(new Rule('min:42'));

Checking for Rule Types

$rules->hasType(Min::class);

Removing Rules

$rules->removeType(Min::class);

Example Implementation

use Spatie\LaravelData\Support\DataProperty;
use Spatie\LaravelData\Support\Validation\PropertyRules;
use Spatie\LaravelData\Support\Validation\ValidationContext;
use Spatie\LaravelData\Support\Validation\RuleInferrer;
use Spatie\LaravelData\Support\Validation\ValidationRule\Min;
use Spatie\LaravelData\Support\Validation\ValidationRule\Max;

class AgeRuleInferrer implements RuleInferrer
{
    public function handle(
        DataProperty $property,
        PropertyRules $rules,
        ValidationContext $context
    ): PropertyRules {
        if ($property->name === 'age') {
            $rules->add(new Min(0));
            $rules->add(new Max(120));
        }

        return $rules;
    }
}

Registration

Rule inferrers must be registered in the config/data.php config file:

'rule_inferrers' => [
    // Default inferrers...
    App\Data\RuleInferrers\AgeRuleInferrer::class,
],

Return Value

A rule inferrer must always return a PropertyRules collection.