4. Inline Validation

The inline validation is about delegating model validation to a dedicated service. The current validation implementation built in the Symfony framework is very powerful as it allows to declare validation on a : class, field and getter. However, these declarations can take a while to code for complex rules. As rules must be a set of a Constraint and a Validator instances.

The inline validation tries to provide a nice solution by introducing an ErrorElement object. The object can be used to check assertions against the model:

$errorElement
    ->with('settings.url')
        ->assertNotNull([])
        ->assertNotBlank()
    ->end()
    ->with('settings.title')
        ->assertNotNull([])
        ->assertNotBlank()
        // for minimum length constraint
        ->assertLength(['min' => 50])
        // for maximum length constraint
        ->assertLength(['max' => 100])
        ->addViolation('ho yeah!')
    ->end();

// ...

if (/* complex rules */) {
    $errorElement
        ->with('value')
            ->addViolation('Fail to check the complex rules')
        ->end();
}

// ...

/* Specify the translation domain */
$errorElement
    ->with('value')
        ->addViolation('translation_key_with_{var}', ['%var%' => 'value'], null, 'translation_domain')
    ->end();

// ...

/* conditional validation */
if ($this->getSubject()->getState() == Post::STATUS_ONLINE) {
    $errorElement
        ->with('enabled')
            ->assertNotNull()
            ->assertTrue()
        ->end();
}

Note

This solution relies on the validator component so validation defined by the validator component will be used.

Tip

You can also use $errorElement->addConstraint(new \Symfony\Component\Validator\Constraints\NotBlank()) instead of calling assertNotBlank().

You can also use $errorElement->addConstraint(new \Symfony\Component\Validator\Constraints\Length(['min'=>5, 'max'=>100]) instead of calling assertLength().

4.1. Using this Validator

Add the InlineConstraint class constraint to your bundle’s validation configuration:

  • YAML
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    # src/Application/Sonata/PageBundle/Resources/config/validation.yaml

Application\Sonata\PageBundle\Entity\Block:
    constraints:
        - Sonata\Form\Validator\Constraints\InlineConstraint:
            service: sonata.page.cms.page
            method: validateBlock
  • XML
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    <!-- src/Application/Sonata/PageBundle/Resources/config/validation.xml -->

<?xml version="1.0" ?>
<constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping http://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">

    <class name="Application\Sonata\PageBundle\Entity\Block">
        <constraint name="Sonata\Form\Validator\Constraints\InlineConstraint">
            <option name="service">sonata.page.cms.page</option>
            <option name="method">validateBlock</option>
        </constraint>
    </class>
</constraint-mapping>

There are two important options:

  • service: the service where the validation method is defined
  • method: the service’s method to call

Note

If the service or method is not a string, you will need to re-attach the validation on each request. Set the serializingWarning option to true once it is done.

The method must accept two arguments:

  • ErrorElement: the instance where assertion can be checked
  • value: the object instance

4.2. Example from the SonataPageBundle

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namespace Sonata\PageBundle\Block;

use Sonata\PageBundle\Model\PageInterface;
use Sonata\Form\Validator\ErrorElement;
use Sonata\BlockBundle\Block\BaseBlockService;
use Sonata\BlockBundle\Model\BlockInterface;

class RssBlockService extends BaseBlockService
{
    // ...

    public function validateBlock(ErrorElement $errorElement, BlockInterface $block)
    {
        $errorElement
            ->with('settings.url')
                ->assertNotNull([])
                ->assertNotBlank()
            ->end()
            ->with('settings.title')
                ->assertNotNull([])
                ->assertNotBlank()

                // for minimum length constraint
                ->assertLength(['min' => 50])

                // for maximum length constraint
                ->assertLength(['max' => 100])
                ->addViolation('ho yeah!')
            ->end();
    }
}