Usage of Validator

This document provides a detailed guide on how to use the Validator feature.

Using the Validator Trait

1. Include the Trait in Your Class

First, you need to include the Validator trait in the class where you want to use it.

use Butterfly\Core\Trait\Validator;

class SomeClass
{
    use Validator;

    ...
}

2. Using Validation

Example: Checking for Validation Errors

In the following example, the someAction method validates incoming data and checks for validation errors.

use Symfony\Component\Validator\Constraints as Assert;

public function someAction()
{
    // Validate incoming data
    if ($response = $this->validate([
        'filter' => [
            new Assert\Required(),
            new Assert\NotBlank(),
        ],
        'sort' => new Assert\Optional()
    ])) {
        // If there are errors, return the response containing the errors
        return $response;
    }

    // Get validated data
    $filter = \Input::get('filter');
    $sort = \Input::get('sort');

    // Return a successful response
    return [
        'status' => 'success',
        'message' => 'Hello World'
    ];
}

Defining Validation Rules

With Symfony Validator, you can define various validation rules. Here are some examples:

use Symfony\Component\Validator\Constraints as Assert;

$rules = [
    'name' => [
        new Assert\Required(),
        new Assert\NotBlank(),
        new Assert\Length(['min' => 3, 'max' => 50])
    ],
    'email' => [
        new Assert\Required(),
        new Assert\Email()
    ],
    'age' => [
        new Assert\Optional(),
        new Assert\Type('integer'),
        new Assert\Range(['min' => 18, 'max' => 99])
    ]
];

You can pass these rules as a parameter to the validate method.

use Symfony\Component\Validator\Constraints as Assert;

public function someAction()
{
    $rules = [
        'name' => [
            new Assert\Required(),
            new Assert\NotBlank(),
            new Assert\Length(['min' => 3, 'max' => 50])
        ],
        'email' => [
            new Assert\Required(),
            new Assert\Email()
        ],
        'age' => [
            new Assert\Optional(),
            new Assert\Type('integer'),
            new Assert\Range(['min' => 18, 'max' => 99])
        ]
    ];

    if ($response = $this->validate($rules)) {
        return $response;
    }

    // Process validated data
    $name = \Input::get('name');
    $email = \Input::get('email');
    $age = \Input::get('age');

    return [
        'status' => 'success',
        'message' => 'Data validated successfully'
    ];
}

These examples demonstrate how to use the validate method and define validation rules. With the flexibility of Symfony Validator, you can easily define and use validation rules that suit your needs.

Custom Rule

This section explains how to create and use a custom validation rule in Validator. We will use the example of validating an American phone number format.

Step-by-Step Guide to Creating a Custom Rule

Create Folder Structure

Create the following folder structure in your project:

Project Path

├── app
│   ├── Validator
│   │   ├── AmericanNumber.php
│   │   └── AmericanNumberValidator.php

1. Create the Constraint Class

First, create a constraint class that defines the validation message and the validator class it uses.

<?php

namespace App\Validator;

use Symfony\Component\Validator\Constraint;

/**
 * @Annotation
 */
class AmericanNumber extends Constraint
{
    public string $message = 'The string "{{ string }}" is not a valid American number.';

    public function validatedBy(): string
    {
        return 'App\Validator\AmericanNumberValidator';
    }
}

2. Create the Validator Class

Next, create the validator class that contains the logic for validating the value.

<?php

namespace App\Validator;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;
use Symfony\Component\Validator\Exception\UnexpectedValueException;

class AmericanNumberValidator extends ConstraintValidator
{
    public function validate($value, Constraint $constraint): void
    {
        if (!$constraint instanceof AmericanNumber) {
            throw new UnexpectedTypeException($constraint, AmericanNumber::class);
        }

        if (null === $value || '' === $value) {
            return;
        }

        if (!is_string($value)) {
            throw new UnexpectedValueException($value, 'string');
        }

        if (preg_match('/^\d{3}-\d{3}-\d{4}$/', $value)) {
            return;
        }

        $this->context->buildViolation($constraint->message)
            ->setParameter('{{ string }}', $value)
            ->addViolation();
    }
}

3. Use the Custom Rule

Finally, use the custom validation rule in your code.

use App\Validator\AmericanNumber;

if ($response = $this->validate([
    'phone_number' => [
        new AmericanNumber(),
    ],
])) {
    return $response;
}

Summary Custom Rule

To create a custom validation rule in Symfony Validator:

1. Create folder structure.

2. Create the Constraint Class: Define the validation message and the validator class.

3. Create the Validator Class: Implement the validation logic.

4. Use the Custom Rule: Apply the custom rule in your validation logic.

By following these steps, you can create custom validation rules tailored to your specific requirements.

Customised Language

Customize language for validation messages.

To override the default language file, we need to open the Langs/validations folders under the app folder. Then we create the file for the language we want. Ex. (lang.en.php)

It will be enough to add the text we want to translate. You can find an example below.

return [
    'This value should be blank.' => 'This place can\'t be left empty.',
    ...
    ...
];