Regex

Version: 3.3
Edit this page

Warning: You are browsing the documentation for version 3.3 which is not maintained anymore.

If some of your projects are still using this version, consider upgrading.

Regex

Validates that a value matches a regular expression.

Applies to property or method
Options
Class Regex
Validator RegexValidator

Basic Usage

Suppose you have a description field and you want to verify that it begins with a valid word character. The regular expression to test for this would be /^\w+/, indicating that you're looking for at least one or more word characters at the beginning of your string:

  • Annotations
  • YAML
  • XML
  • PHP 
1
2
3
4
5
6
7
8
9
10
11
12
// src/AppBundle/Entity/Author.php
namespace AppBundle\Entity;

use Symfony\Component\Validator\Constraints as Assert;

class Author
{
    /**
     * @Assert\Regex("/^\w+/")
     */
    protected $description;
}

Alternatively, you can set the match option to false in order to assert that a given string does not match. In the following example, you'll assert that the firstName field does not contain any numbers and give it a custom message:

  • Annotations
  • YAML
  • XML
  • PHP 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
// src/AppBundle/Entity/Author.php
namespace AppBundle\Entity;

use Symfony\Component\Validator\Constraints as Assert;

class Author
{
    /**
     * @Assert\Regex(
     *     pattern="/\d/",
     *     match=false,
     *     message="Your name cannot contain a number"
     * )
     */
    protected $firstName;
}

Options

pattern

type: string [default option]

This required option is the regular expression pattern that the input will be matched against. By default, this validator will fail if the input string does not match this regular expression (via the preg_match PHP function). However, if match is set to false, then validation will fail if the input string does match this pattern.

htmlPattern

type: string|boolean default: null

This option specifies the pattern to use in the HTML5 pattern attribute. You usually don't need to specify this option because by default, the constraint will convert the pattern given in the pattern option into an HTML5 compatible pattern. This means that the delimiters are removed (e.g. /[a-z]+/ becomes [a-z]+).

However, there are some other incompatibilities between both patterns which cannot be fixed by the constraint. For instance, the HTML5 pattern attribute does not support flags. If you have a pattern like /[a-z]+/i, you need to specify the HTML5 compatible pattern in the htmlPattern option:

  • Annotations
  • YAML
  • XML
  • PHP 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
// src/AppBundle/Entity/Author.php
namespace AppBundle\Entity;

use Symfony\Component\Validator\Constraints as Assert;

class Author
{
    /**
     * @Assert\Regex(
     *     pattern     = "/^[a-z]+$/i",
     *     htmlPattern = "^[a-zA-Z]+$"
     * )
     */
    protected $name;
}

Setting htmlPattern to false will disable client side validation.

match

type: boolean default: true

If true (or not set), this validator will pass if the given string matches the given pattern regular expression. However, when this option is set to false, the opposite will occur: validation will pass only if the given string does not match the pattern regular expression.

message

type: string default: This value is not valid.

This is the message that will be shown if this validator 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.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.