Symfony using NotEqualTo validator with an object - symfony

Question

According to Symfony docs it should be possible to use a NotEqualTo constraint with objects
value
type: mixed [default option]
This option is required. It defines the value to compare to. It can be a string, number or object.
I have the following entity:
<?php
namespace AppBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
use Doctrine\ORM\Mapping\UniqueConstraint;
use Symfony\Component\Validator\Constraints\NotBlank;
use Symfony\Component\Validator\Constraints\NotEqualTo;
/**
* Class Template
* #ORM\Entity(repositoryClass="NoteRepository")
* #ORM\Table(uniqueConstraints={#UniqueConstraint(name="note_unique",columns={"from_id", "to_id"})})
*/
class Note
{
/**
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
* #ORM\Column(type="integer")
* #var $id int
*/
protected $id;
/**
* #ORM\ManyToOne(targetEntity="Template")
* #var $from Template
* #NotBlank()
* #NotEqualTo(value="$to")
*/
protected $from;
/**
* #ORM\ManyToOne(targetEntity="Template")
* #NotBlank()
* #var $to Template
*/
protected $to;
/**
* #ORM\Column(type="text")
* #var $notes string
*/
protected $notes;
}
I want to avoid getting $from == $to, how can I configure the constraint to use an instance of the class Template at validation time or more generrally how can I configure the constraint to use an object
Right now if a dump the values that the validator is receiving
class NotEqualToValidator extends AbstractComparisonValidator
{
/**
* {#inheritdoc}
*/
protected function compareValues($value1, $value2)
{
var_dump($value1);
var_dump($value2);
return $value1 != $value2;
}
}
I get
object(AppBundle\Entity\Template)
string '$to' (length=3)

Answer 1

Okay, despite Symfony docs states to be possible pass object to NotEqualTo Constraint it isn't true when using YML or Annotations.
So in order to dynamically unsure Note::$to is equals (or not equals) to Note::$from you could to use either Getters Constraint Targets or Callback Constraint.
However, there is a third option much easier (IMO): Expression Constraint
Expression Constraint approach
This constraint allows you to use an expression for more complex,
dynamic validation. See Basic Usage for an example. See Callback for a
different constraint that gives you similar flexibility.
Here is an example based on your question:
use Symfony\Component\Validator\Constraints as Assert;
/*
* Entity class...
*/
class Note
{
//...
/**
* #ORM\ManyToOne(targetEntity="Template")
* #var $from Template
* #Assert\NotBlank()
* #Assert\Expression('not (value == this.getTo())')
*/
protected $from;
//...
}
That is, just add #Assert\Expression('not (value == this.getTo())') to $from property.
Constraints Targets: Getters approach
use Symfony\Component\Validator\Constraints as Assert;
/*
* Entity class...
*/
class Note
{
//...
/**
* #Assert\isFalse(message='"from" cannot be equals to "to"')
* #return bool True if self::$from is not equals to self::$to
*/
function isFromAndToNotEqual()
{
return !($this->getFrom() != $this->getTo());
}
//...
}
Setting the property path validation:
Be aware taking this approach (Getters As Constraints Targets) and using validation with forms, it'll not show error messages next/closer to form field.
However, you always can set/config the error_mapping option (in Form type) in order to show the custom errors display next to a specific field, thus the solution would be something like this:
<?php
namespace AppBundle\Form\Type;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
class MyType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('from')
->add('to')
// more fields...
;
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
//...
# it cause error message display next to
# "from" field (or whaterver field you which).
'error_mapping' => array(
'fromAndToNotEqual' => 'from',
),
));
}
}
Please note the current solutions is based on Symfony 2.7, but it
should be work nicely on other older versions (except some details for
Form class, etc).