ExpressionLanguageSyntax.rst

ExpressionLanguageSyntax

This constraint checks that the value is valid as an ExpressionLanguage expression.

.. versionadded:: 5.1

    The ``ExpressionLanguageSyntax`` constraint was introduced in Symfony 5.1.

Applies to	:ref:`property or method <validation-property-target>`
Class	:class:`Symfony\\Component\\Validator\\Constraints\\ExpressionLanguageSyntax`
Validator	:class:`Symfony\\Component\\Validator\\Constraints\\ExpressionLanguageSyntaxValidator`

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.

.. configuration-block::

    .. code-block:: php-annotations

        // src/Entity/Order.php
        namespace App\Entity;

        use Symfony\Component\Validator\Constraints as Assert;

        class Order
        {
            /**
             * @Assert\ExpressionLanguageSyntax
             */
            protected $promotion;

            /**
             * @Assert\ExpressionLanguageSyntax(
             *     allowedVariables={"user", "shipping_centers"}
             * )
             */
            protected $shippingOptions;
        }

    .. code-block:: php-attributes

        // src/Entity/Order.php
        namespace App\Entity;

        use Symfony\Component\Validator\Constraints as Assert;

        class Order
        {
            #[Assert\ExpressionLanguageSyntax]
            protected $promotion;

            #[Assert\ExpressionLanguageSyntax(
                allowedVariables: ['user', 'shipping_centers'],
            )]
            protected $shippingOptions;
        }

    .. code-block:: yaml

        # config/validator/validation.yaml
        App\Entity\Order:
            properties:
                promotion:
                    - ExpressionLanguageSyntax: ~
                shippingOptions:
                    - ExpressionLanguageSyntax:
                        allowedVariables: ['user', 'shipping_centers']

    .. code-block:: xml

        <!-- 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="ExpressionLanguageSyntax"/>
                </property>
                <property name="shippingOptions">
                    <constraint name="ExpressionLanguageSyntax">
                        <option name="allowedVariables">
                            <value>user</value>
                            <value>shipping_centers</value>
                        </option>
                    </constraint>
                </property>
            </class>
        </constraint-mapping>

    .. code-block:: php

        // 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)
            {
                $metadata->addPropertyConstraint('promotion', new Assert\ExpressionLanguageSyntax());

                $metadata->addPropertyConstraint('shippingOptions', new Assert\ExpressionLanguageSyntax([
                    '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.

message

type: string default: This value should be a valid expression.

This is the message displayed when the validation fails.