README

A color control for the WordPress Customizer with support for alpha channel.

This is a customizer control using the react-color colorpicker.

The control will save either a HEX value (#000000) or RGBA (rgba(0,0,0,0.9)) depending on the opacity of the selected color. If the color is completely opaque, then it will save a HEX value. If the selected color is not completely opaque (has an alpha value smaller than 1) then the value will be saved as RGBA.

Usage

Registering the Control

This is a control containing a JS template. As such, it should be whitelisted in the Customizer. To do that we can use the WP_Customize_Manager::register_control_type method:

add_action( 'customize_register', function( $wp_customize ) {
	$wp_customize->register_control_type( '\WPTRT\Customize\Control\ColorAlpha' );
} );

After we register the control using the above code, we can use it in the customizer using the Customizer API:

use \WPTRT\Customize\Control\ColorAlpha;

add_action( 'customize_register', function( $wp_customize ) {

	$wp_customize->add_setting( 'your_setting_id' , [
		'default'           => 'rgba(0,0,0,0.5)', // Use any HEX or RGBA value.
		'transport'         => 'refresh',
		'sanitize_callback' => 'my_custom_sanitization_callback'
	] );
	$wp_customize->add_control( new ColorAlpha( $wp_customize, 'your_setting_id', [
		'label'      => __( 'My Color', 'mytheme' ),
		'section'    => 'my_section',
		'settings'   => 'your_setting_id',
	] ) );
} );

Available filters

wptrt_color_picker_alpha_url

You can use this filter to change the URL for control assets. By default the control will work out of the box for any plugins and themes installed in wp-content/themes and wp-content/plugins respectively. It is possible however to change the URL by using the wptrt_color_picker_alpha_url filter:

add_filter( 'wptrt_color_picker_alpha_url', function() {
	return get_template_directory_uri() . '/vendor/wptrt/control-color-alpha';
} );

Sanitization

All controls in the WordPress Customizer should have a sanitize_callback defined. You can write your own function and use it as a sanitization callback, or use the example function below:

/**
 * Sanitize colors.
 *
 * @since 1.0.0
 * @param string $value The color.
 * @return string
 */
function my_custom_sanitization_callback( $value ) {
	// This pattern will check and match 3/6/8-character hex, rgb, rgba, hsl, & hsla colors.
	$pattern = '/^(\#[\da-f]{3}|\#[\da-f]{6}|\#[\da-f]{8}|rgba\(((\d{1,2}|1\d\d|2([0-4]\d|5[0-5]))\s*,\s*){2}((\d{1,2}|1\d\d|2([0-4]\d|5[0-5]))\s*)(,\s*(0\.\d+|1))\)|hsla\(\s*((\d{1,2}|[1-2]\d{2}|3([0-5]\d|60)))\s*,\s*((\d{1,2}|100)\s*%)\s*,\s*((\d{1,2}|100)\s*%)(,\s*(0\.\d+|1))\)|rgb\(((\d{1,2}|1\d\d|2([0-4]\d|5[0-5]))\s*,\s*){2}((\d{1,2}|1\d\d|2([0-4]\d|5[0-5]))\s*)|hsl\(\s*((\d{1,2}|[1-2]\d{2}|3([0-5]\d|60)))\s*,\s*((\d{1,2}|100)\s*%)\s*,\s*((\d{1,2}|100)\s*%)\))$/';
	\preg_match( $pattern, $value, $matches );
	// Return the 1st match found.
	if ( isset( $matches[0] ) ) {
		if ( is_string( $matches[0] ) ) {
			return $matches[0];
		}
		if ( is_array( $matches[0] ) && isset( $matches[0][0] ) ) {
			return $matches[0][0];
		}
	}
	// If no match was found, return an empty string.
	return '';
}

Advanced Usage

This control allows you to save the value as either a string or an array. The default behavior is to save a string, but you can easily alter that by using the choices argument in the control:

$wp_customize->add_control( new ColorAlpha( $wp_customize, 'your_setting_id', [
	'label'    => __( 'My Color', 'mytheme' ),
	'section'  => 'my_section',
	'settings' => 'your_setting_id',
	'choices'  => [
		'save_as' => 'array',
	]
] ) );

The value will then be saved using a format like this:

[
	'r'    => 107, // Red.
	'g'    => 55, // Green.
	'b'    => 119, // Blue.
	'h'    => 289, // Hue.
	's'    => 37, // Saturation.
	'l'    => 34, // Lightness.
	'a'    => 0.82, // Alpha
	'hex'  => '#6b3777', // The HEX code of the color (alpha = 1)
	'css'  => 'rgba(107,55,119,0.82)', // The CSS value of the selected color.
	'a11y' => [ // An array of accessibility-related properties.
		'luminance'                         => 0.0719,
		// Contrast with white (value 0 - 21).
		'distanceFromWhite'                 => 8.613,
		// Contrast with black (value 0 - 21).
		'distanceFromBlack'                 => 2.438,
		// Maximum contrasting color. Use this to get the text-color
		// if the colorpicker is used to select a background-color.
		'maxContrastColor'                  => '#ffffff',
		// Readable text-colors on white background preserving the hue.
		// The 1st value has a minimum contrast of 7:1 with white.
		// The 2nd value has a minimum contrast of 4.5:1 with white.
		'readableContrastingColorFromWhite' => [ '#6b3777', '#6b3777' ],
		// Readable text-colors on black background preserving the hue.
		// The 1st value has a minimum contrast of 7:1 with black.
		// The 2nd value has a minimum contrast of 4.5:1 with black.
		'readableContrastingColorFromBlack' => [ '#bc83c7', '#a458b5' ],
		// True if the color is dark.
		'isDark'                            => true
	],
]

Array Sanitization

If you choose to save the value of this control as an array, then you will need to change the sanitization function for this setting. You can write your own, or use the one below.

/**
 * Sanitize colors.
 *
 * @since 1.0.0
 * @param array $value The color.
 * @return array
 */
function my_custom_sanitization_callback( $value ) {
	return [
		'r' => (int) $value['r'],
		'g' => (int) $value['g'],
		'b' => (int) $value['b'],
		'h' => (int) $value['h'],
		's' => (int) $value['s'],
		'l' => (int) $value['l'],
		'a' => (float) $value['a'],

		'hex' => my_custom_color_string_sanitization_callback( $value['hex'] ),
		'css' => my_custom_color_string_sanitization_callback( $value['css'] ),

		'a11y' => [
			'luminance'         => (float) $value['a11y']['luminance'],
			'distanceFromWhite' => (float) $value['a11y']['distanceFromWhite'],
			'distanceFromBlack' => (float) $value['a11y']['distanceFromBlack'],
			'maxContrastColor'  => my_custom_color_string_sanitization_callback( $value['a11y']['maxContrastColor'] ),
			'isDark'            => (float) $value['a11y']['isDark'],

			'readableContrastingColorFromWhite' => [
				my_custom_color_string_sanitization_callback( $value['a11y']['readableContrastingColorFromWhite'][0] ),
				my_custom_color_string_sanitization_callback( $value['a11y']['readableContrastingColorFromWhite'][1] ),
			],
			'readableContrastingColorFromBlack' => [
				my_custom_color_string_sanitization_callback( $value['a11y']['readableContrastingColorFromBlack'][0] ),
				my_custom_color_string_sanitization_callback( $value['a11y']['readableContrastingColorFromBlack'][1] ),
			]
		]
	];
}

/**
 * Sanitize colors.
 *
 * @since 1.0.0
 * @param string $value The color.
 * @return string
 */
function my_custom_color_string_sanitization_callback( $value ) {
	// This pattern will check and match 3/6/8-character hex, rgb, rgba, hsl, & hsla colors.
	$pattern = '/^(\#[\da-f]{3}|\#[\da-f]{6}|\#[\da-f]{8}|rgba\(((\d{1,2}|1\d\d|2([0-4]\d|5[0-5]))\s*,\s*){2}((\d{1,2}|1\d\d|2([0-4]\d|5[0-5]))\s*)(,\s*(0\.\d+|1))\)|hsla\(\s*((\d{1,2}|[1-2]\d{2}|3([0-5]\d|60)))\s*,\s*((\d{1,2}|100)\s*%)\s*,\s*((\d{1,2}|100)\s*%)(,\s*(0\.\d+|1))\)|rgb\(((\d{1,2}|1\d\d|2([0-4]\d|5[0-5]))\s*,\s*){2}((\d{1,2}|1\d\d|2([0-4]\d|5[0-5]))\s*)|hsl\(\s*((\d{1,2}|[1-2]\d{2}|3([0-5]\d|60)))\s*,\s*((\d{1,2}|100)\s*%)\s*,\s*((\d{1,2}|100)\s*%)\))$/';
	\preg_match( $pattern, $value, $matches );
	// Return the 1st match found.
	if ( isset( $matches[0] ) ) {
		if ( is_string( $matches[0] ) ) {
			return $matches[0];
		}
		if ( is_array( $matches[0] ) && isset( $matches[0][0] ) ) {
			return $matches[0][0];
		}
	}
	// If no match was found, return an empty string.
	return '';
}

Autoloading

You'll need to use an autoloader with this. Ideally, this would be Composer. However, we have a basic autoloader available to include with themes if needed.

Composer

From the command line:

composer require wptrt/control-color-alpha

WPTRT Autoloader

If using the WPTRT autoloader, use the following code:

include get_theme_file_path( 'path/to/autoload/src/Loader.php' );

$loader = new \WPTRT\Autoload\Loader();
$loader->add( 'WPTRT\\Customize\\Control', get_theme_file_path( 'path/to/control-color-alpha/src' ) );
$loader->register();