symfony3 Validation Symfony validation using annotations

Example

• Enable validation using annotations in app/config/config.yml file

framework:
    validation: { enable_annotations: true }

• Create an Entity in AppBundle/Entity directory. The validations are made with @Assert annotations.

<?php
# AppBundle/Entity/Car.php


namespace AppBundle\Entity;


use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;

/**
 * Car
 *
 * @ORM\Table(name="cars")
 * @ORM\Entity(repositoryClass="AppBundle\Repository\CarRepository")
 */
class Car
{
    /**
     * @var int
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var string
     *
     * @ORM\Column(name="name", type="string", length=50)
     * @Assert\NotBlank(message="Please provide a name")
     * @Assert\Length(
     *     min=3,
     *     max=50,
     *     minMessage="The name must be at least 3 characters long",
     *     maxMessage="The name cannot be longer than 50 characters"
     * )
     * @Assert\Regex(
     *     pattern="/^[A-Za-z]+$/",
     *     message="Only letters allowed"
     * )
     */
    private $name;

    /**
     * @var string
     *
     * @ORM\Column(name="number", type="integer")
     * @Assert\NotBlank(message="Please provide a number")
     * @Assert\Length(
     *     min=1,
     *     max=3,
     *     minMessage="The number field must contain at least one number",
     *     maxMessage="The number field must contain maximum 3 numbers"
     * )
     * @Assert\Regex(
     *     pattern="/^[0-9]+$/",
     *     message="Only numbers allowed"
     * )
     */
    private $number;


    /**
     * Get id
     *
     * @return int
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Set name
     *
     * @param string $name
     *
     * @return Car
     */
    public function setName($name)
    {
        $this->name = $name;

        return $this;
    }

    /**
     * Get name
     *
     * @return string
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Set number
     *
     * @param integer $number
     *
     * @return Car
     */
    public function setNumber($number)
    {
        $this->number = $number;

        return $this;
    }

    /**
     * Get number
     *
     * @return integer
     */
    public function getNumber()
    {
        return $this->number;
    }
}

• Create a new form in AppBundle/Form directory.

<?php
# AppBundle/Form/CarType.php

namespace AppBundle\Form;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\Extension\Core\Type\IntegerType;

class CarType extends AbstractType
{
    /**
     * @param FormBuilderInterface $builder
     * @param array $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('name', TextType::class, ['label'=>'Name'])
            ->add('number', IntegerType::class, ['label'=>'Number'])
        ;
    }

    /**
     * @param OptionsResolver $resolver
     */
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => 'AppBundle\Entity\Car'
        ));
    }

    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        // TODO: Implement setDefaultOptions() method.
    }

    public function getName()
    {
        return 'car_form';
    }
}

• Create a new route and a new action method in AppBundle/Controller/DefaultController.php. The route will be declared with annotations too, so make sure you've imported this route in the main route file (app/config/routing.yml).

<?php

namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\Annotation\Route;
use AppBundle\Entity\Car;
use AppBundle\Form\CarType;

class DefaultController extends Controller
{
    /**
     * @Route("/car", name="app_car")
     */
    public function carAction(Request $request)
    {
        $car = new Car();

        $form = $this->createForm(
            CarType::class,
            $car,
            [
                'action' => $this->generateUrl('app_car'),
                'method'=>'POST',
                'attr'=>[
                    'id'=>'form_car',
                    'class'=>'car_form'
                ]
            ]
        );

        $form->handleRequest($request);

        return $this->render(
            'AppBundle:Default:car.html.twig',[
                'form'=>$form->createView()
            ]
        );
    }
}

• Create the view in AppBundle/Resources/views/Default/car.html.twig.

{% extends '::base.html.twig' %}

{% block body %}
    {{ form_start(form, {'attr': {'novalidate':'novalidate'}}) }}
    {{ form_row(form.name) }}
    {{ form_row(form.number) }}
    <button type="submit">Go</button>
    {{ form_end(form) }}
{% endblock %}

• Start Symfony's built-in server (php bin/console server:run) and access 127.0.0.1:8000/car route in your browser. There should be a form consisting of two input boxes and a submit button. If you press the submit button without entering any data into the input boxes, then the error messages will be displayed.