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CssColor

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Validates that a value is a valid CSS color. The underlying value is casted to a string before being validated.

Applies to property or method
Class CssColor
Validator CssColorValidator

Basic Usage

In the following example, the $defaultColor value must be a CSS color defined in any of the valid CSS formats (e.g. red, #369, hsla(0, 0%, 20%, 0.4)); the $accentColor must be a CSS color defined in hexadecimal format; and $currentColor must be a CSS color defined as any of the named CSS colors:

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

use Symfony\Component\Validator\Constraints as Assert;

class Bulb
{
    #[Assert\CssColor]
    protected string $defaultColor;

    #[Assert\CssColor(
        formats: Assert\CssColor::HEX_LONG,
        message: 'The accent color must be a 6-character hexadecimal color.',
    )]
    protected string $accentColor;

    #[Assert\CssColor(
        formats: [Assert\CssColor::BASIC_NAMED_COLORS, Assert\CssColor::EXTENDED_NAMED_COLORS],
        message: 'The color '{{ value }}' is not a valid CSS color name.',
    )]
    protected string $currentColor;
}

Note

As with most of the other constraints, null and empty strings are considered valid values. This is to allow them to be optional values. If the value is mandatory, a common solution is to combine this constraint with NotBlank.

Options

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 is not a valid CSS color.

This message is shown if the underlying data is not a valid CSS color.

You can use the following parameters in this message:

Parameter Description
{{ value }} The current (invalid) value

formats

type: string | array

By default, this constraint considers valid any of the many ways of defining CSS colors. Use the formats option to restrict which CSS formats are allowed. These are the available formats (which are also defined as PHP constants; e.g. Assert\CssColor::HEX_LONG):

  • hex_long
  • hex_long_with_alpha
  • hex_short
  • hex_short_with_alpha
  • basic_named_colors
  • extended_named_colors
  • system_colors
  • keywords
  • rgb
  • rgba
  • hsl
  • hsla

hex_long

A regular expression. Allows all values which represent a CSS color of 6 characters (in addition of the leading #) and contained in ranges: 0 to 9 and A to F (case insensitive).

Examples: #2F2F2F, #2f2f2f

hex_long_with_alpha

A regular expression. Allows all values which represent a CSS color with alpha part of 8 characters (in addition of the leading #) and contained in ranges: 0 to 9 and A to F (case insensitive).

Examples: #2F2F2F80, #2f2f2f80

hex_short

A regular expression. Allows all values which represent a CSS color of strictly 3 characters (in addition of the leading #) and contained in ranges: 0 to 9 and A to F (case insensitive).

Examples: #CCC, #ccc

hex_short_with_alpha

A regular expression. Allows all values which represent a CSS color with alpha part of strictly 4 characters (in addition of the leading #) and contained in ranges: 0 to 9 and A to F (case insensitive).

Examples: #CCC8, #ccc8

basic_named_colors

Any of the valid color names defined in the W3C list of basic named colors (case insensitive).

Examples: black, red, green

extended_named_colors

Any of the valid color names defined in the W3C list of extended named colors (case insensitive).

Examples: aqua, brown, chocolate

system_colors

Any of the valid color names defined in the CSS WG list of system colors (case insensitive).

Examples: LinkText, VisitedText, ActiveText, ButtonFace, ButtonText

keywords

Any of the valid keywords defined in the CSS WG list of keywords (case insensitive).

Examples: transparent, currentColor

rgb

A regular expression. Allows all values which represent a CSS color following the RGB notation, with or without space between values.

Examples: rgb(255, 255, 255), rgb(255,255,255)

rgba

A regular expression. Allows all values which represent a CSS color with alpha part following the RGB notation, with or without space between values.

Examples: rgba(255, 255, 255, 0.3), rgba(255,255,255,0.3)

hsl

A regular expression. Allows all values which represent a CSS color following the HSL notation, with or without space between values.

Examples: hsl(0, 0%, 20%), hsl(0,0%,20%)

hsla

A regular expression. Allows all values which represent a CSS color with alpha part following the HSLA notation, with or without space between values.

Examples: hsla(0, 0%, 20%, 0.4), hsla(0,0%,20%,0.4)

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.
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