ExpressionSyntax
This constraint checks that the value is valid as an ExpressionLanguage expression.
6.1
This constraint was introduced in Symfony 6.1 and deprecates the previous ExpressionLanguageSyntax constraint.
Applies to | property or method |
Class | ExpressionSyntax |
Validator | ExpressionSyntaxValidator |
Basic Usage
The following constraints ensure that:
- the
promotion
property stores a value which is valid as an ExpressionLanguage expression; - the
shippingOptions
property also ensures that the expression only uses certain variables.
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// src/Entity/Order.php
namespace App\Entity;
use Symfony\Component\Validator\Constraints as Assert;
class Order
{
#[Assert\ExpressionSyntax]
protected string $promotion;
#[Assert\ExpressionSyntax(
allowedVariables: ['user', 'shipping_centers'],
)]
protected string $shippingOptions;
}
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# config/validator/validation.yaml
App\Entity\Order:
properties:
promotion:
- ExpressionSyntax: ~
shippingOptions:
- ExpressionSyntax:
allowedVariables: ['user', 'shipping_centers']
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<!-- config/validator/validation.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<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 https://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">
<class name="App\Entity\Order">
<property name="promotion">
<constraint name="ExpressionSyntax"/>
</property>
<property name="shippingOptions">
<constraint name="ExpressionSyntax">
<option name="allowedVariables">
<value>user</value>
<value>shipping_centers</value>
</option>
</constraint>
</property>
</class>
</constraint-mapping>
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// src/Entity/Student.php
namespace App\Entity;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Mapping\ClassMetadata;
class Order
{
// ...
public static function loadValidatorMetadata(ClassMetadata $metadata): void
{
$metadata->addPropertyConstraint('promotion', new Assert\ExpressionSyntax());
$metadata->addPropertyConstraint('shippingOptions', new Assert\ExpressionSyntax([
'allowedVariables' => ['user', 'shipping_centers'],
]));
}
}
Options
allowedVariables
type: array
or null
default: null
If this option is defined, the expression can only use the variables whose names
are included in this option. Unset this option or set its value to null
to
allow any variables.
groups
type: array
| string
default: null
It defines the validation group or groups of this constraint. Read more about validation groups.
message
type: string
default: This value should be a valid expression.
This is the message displayed when the validation fails.
payload
type: mixed
default: null
This option can be used to attach arbitrary domain-specific data to a constraint. The configured payload is not used by the Validator component, but its processing is completely up to you.
For example, you may want to use several error levels to present failed constraints differently in the front-end depending on the severity of the error.