symfony · OskarStark · Feb 24, 2020 · Feb 21, 2020 · OskarStark · Feb 23, 2020
diff --git a/reference/constraints.rst b/reference/constraints.rst
@@ -63,6 +63,7 @@ Validation Constraints Reference
    constraints/Isbn
    constraints/Issn
 
+   constraints/Sequentially
    constraints/Compound
    constraints/Callback
    constraints/Expression

diff --git a/reference/constraints/Sequentially.rst b/reference/constraints/Sequentially.rst
@@ -0,0 +1,142 @@
+Sequentially
+============
+
+This constraint allows you to apply a set of rules that should be validated
+step-by-step, allowing to interrupt the validation once the first violation is raised.
+
+As an alternative in situations ``Sequentially`` cannot solve, you may consider
+using :doc:`GroupSequence</validation/sequence_provider>` which allows more control.
+
+.. versionadded:: 5.1
+
+    The ``Sequentially`` constraint was introduced in Symfony 5.1.
+
+==========  ===================================================================
+Applies to  :ref:`property or method <validation-property-target>`
+Options     - `constraints`_
+            - `groups`_
+            - `payload`_
+Class       :class:`Symfony\\Component\\Validator\\Constraints\\Sequentially`
+Validator   :class:`Symfony\\Component\\Validator\\Constraints\\SequentiallyValidator`
+==========  ===================================================================
+
+Basic Usage
+-----------
+
+Suppose that you have a ``Place`` object with an ``$address`` property which
+must match the following requirements:
+- it's a non-blank string
+- of at least 10 chars long
+- with a specific format
+- and geolocalizable using an external service
+
+In such situations, you may encounter three issues:
+- the ``Length`` or ``Regex`` constraints may fail hard with a :class:`Symfony\\Component\\Validator\\Exception\\UnexpectedValueException`
+exception if the actual value is not a string, as enforced by ``Type``.
+- you may end with multiple error messages for the same property
+- you may perform a useless and heavy external call to geolocalize the address,
+while the format isn't valid.
+
+You can validate each of these constraints sequentially to solve these issues:
+
+.. configuration-block::
+
+    .. code-block:: php-annotations
+
+        // src/Localization/Place.php
+        namespace App\Localization;
+
+        use App\Validator\Constraints as AcmeAssert;
+        use Symfony\Component\Validator\Constraints as Assert;
+
+        class Place
+        {
+            /**
+             * @var string
+             *
+             * @Assert\Sequentially({
+             *     @Assert\NotBlank(),
+             *     @Assert\Type("string"),
+             *     @Assert\Length(min=10),
+             *     @Assert\Regex(Place::ADDRESS_REGEX),
+             *     @AcmeAssert\Geolocalizable(),
+             * })
+             */
+            public $address;
+        }
+
+    .. code-block:: yaml
+
+        # config/validator/validation.yaml
+        App\Localization\Place:
+            properties:
+                address:
+                    - Sequentially:
+                        - NotBlank: ~
+                        - Type: string
+                        - Length: { min: 10 }
+                        - Regex: !php/const App\Localization\Place::ADDRESS_REGEX
+                        - App\Validator\Constraints\Geolocalizable: ~
+
+    .. 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\Localization\Place">
+                <property name="address">
+                    <constraint name="Sequentially">
+                            <constraint name="NotBlank"/>
+                            <constraint name="Type">string</constraint>
+                            <constraint name="Length">
+                                <option name="min">10</option>
+                            </constraint>
+                            <constraint name="Regex">
+                                <option name="pattern">/address-regex/</option>
+                            </constraint>
+                            <constraint name="App\Validator\Constraints\Geolocalizable"/>
+                    </constraint>
+                </property>
+            </class>
+        </constraint-mapping>
+
+    .. code-block:: php
+
+        // src/Localization/Place.php
+        namespace App\Localization;
+
+        use App\Validator\Constraints as AcmeAssert;
+        use Symfony\Component\Validator\Constraints as Assert;
+        use Symfony\Component\Validator\Mapping\ClassMetadata;
+
+        class Place
+        {
+            public static function loadValidatorMetadata(ClassMetadata $metadata)
+            {
+                $metadata->addPropertyConstraint('address', new Assert\Sequentially([
+                    new Assert\NotBlank(),
+                    new Assert\Type("string"),
+                    new Assert\Length(['min' => 10]),
+                    new Assert\Regex(self::ADDRESS_REGEX),
+                    new AcmeAssert\Geolocalizable(),
+                ]));
+            }
+        }
+
+Options
+-------
+
+``constraints``
+~~~~~~~~~~~~~~~
+
+**type**: ``array`` [:ref:`default option <validation-default-option>`]
+
+This required option is the array of validation constraints that you want
+to apply sequentially.
+
+.. include:: /reference/constraints/_groups-option.rst.inc
+
+.. include:: /reference/constraints/_payload-option.rst.inc
diff --git a/reference/constraints/map.rst.inc b/reference/constraints/map.rst.inc
@@ -84,6 +84,7 @@ Financial and other Number Constraints
 Other Constraints
 ~~~~~~~~~~~~~~~~~
 
+* :doc:`Sequentially </reference/constraints/Sequentially>`
 * :doc:`Compound </reference/constraints/Compound>`
 * :doc:`Callback </reference/constraints/Callback>`
 * :doc:`Expression </reference/constraints/Expression>`

diff --git a/validation/sequence_provider.rst b/validation/sequence_provider.rst
@@ -355,3 +355,14 @@ provides a sequence of groups to be validated:
                 // ...
             }
         }
+
+How to Sequentially Apply Constraints on a Single Property
+==========================================================
+
+Sometimes, you may want to apply constraints sequentially on a single
+property. The :doc:`Sequentially constraint</reference/constraints/Sequentially>`
+can solve this for you in a more straightforward way than using a ``GroupSequence``.
+
+.. versionadded:: 5.1
+
+    The ``Sequentially`` constraint was introduced in Symfony 5.1.