Symfony Form Constraints connection beetwen fields - php

Question

I have question about constraints,
https://symfony.com/doc/current/reference/constraints.html
I have entity with multiple checkboxes (boolean type) .
Now i need some non-standard logic here like:
if checkbox A is checked then checkbox B must be checked too.
if checkboxes A,B,C are checked then checkbox D must be checked too
And now the question is :
Am i able to make logic like this with constraints (if yes - it would be grat if someone can provide example) ? or only way is to move this logic to controller ?

Answer 1

As your logic is specific, you have to do some specific code to validate it.
Symfony gives you 3 tools to do it:
The Callback Constraints which is a custom php function (see #Yoshi answer's)
The Expression Constraint which is a custom expression parsed. Example:
/**
* #Assert\Expression(
* "'1' in this.getCheckboxValues() and !('3' in this.getCheckboxValues())",
* )
*/
Or your own custom constraint

Answer 2

I think the simplest solution would be to use a callback contraint:
Something like:
<?php
namespace App\Entity;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Context\ExecutionContextInterface;
class Entity
{
private $checkbox_a = false;
private $checkbox_b = false;
private $checkbox_c = false;
private $checkbox_d = false;
/**
* #Assert\Callback
*
* #param ExecutionContextInterface $context
* #param mixed $payload
*/
public function validate(ExecutionContextInterface $context, $payload)
{
if ($this->checkbox_a && !$this->checkbox_b) {
$context->buildViolation('Must be checked because of checkbox_a!')
->atPath('checkbox_b')
->addViolation();
}
if ($this->checkbox_a && $this->checkbox_b && $this->checkbox_c && !$this->checkbox_d) {
$context->buildViolation('Must be checked because of all others are checked!')
->atPath('checkbox_d')
->addViolation();
}
}
}