ariColor

A PHP library for color manipulation in themes and plugins

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ariColor is a PHP library that will hopefully help WordPress theme developers do their job easier and more effectively.

It does not provide you with methods like lighten(), darken() etc. Instead, what it does is give you the ability to create these yourself with extreme ease by giving you all the properties of a color at hand, and allowing you to manipulate them however you see fit.

Example:

First, let's create our color object:

$color = ariColor::newColor( '#049CBE', 'hex' );

If you don't like using that method you can write your own proxy function:

function my_custom_color_function( $color = '#ffffff' ) {
    return ariColor::newColor( $color, 'auto' );
}

Notice that we used auto as the mode. If you use auto or completely omit the 2nd argument, ariColor will auto-detect it for you. You can use rgb, rgba, hsl, hsla, or even arrays as colors.

Then you can use it like this:

$color = my_custom_color_function( '#049CBE' );

Say you want to get the values for red, green, blue:

// Get red value:
$red = $color->red;
// Get green value:
$green = $color->green;
// Get blue value
$blue = $color->blue;

Or you want to get the hue, saturation, lightness or even luminance of your color:

// Get hue
$hue = $color->hue;
// Get saturation
$saturation = $color->saturation;
// Get lightness
$lightness = $color->lightness;
// Get luminance
$luminance = $color->luminance;

Scenario 1:

You have an option where users can define the background color for their <body>. In order to make sure the text is always readable, you can either give them a 2nd option to set the text color, or auto-calculate it for readability.

Example function that given a background color decides if we're going to use white/black text color:

/**
 * determine the luminance of the given color
 * and then return #FFFFFF or #222222 so that our text is always readable
 * 
 * @param $background color string|array
 *
 * @return string (hex color)
 */
function custom_get_readable_color( $background_color = '#FFFFFF' ) {
    $color = ariColor::newColor( $background_color );
    return ( 127 < $color->luminance ) ? '#222222' : '#FFFFFF';
}

Usage: 

$text_color = custom_get_readable_color( get_theme_mod( 'bg_color', '#ffffff' ) );

Easy, right? What we did above is simply check the luminance of the background color, and then if the luminance is greater than 127 we return black, otherwise we return white.

Scenario 2:

We have a HEX color, and we want to get the same color as rgba, with an opacity of 0.7:

function my_theme_get_semitransparent_color( $color ) {
    // Create the color object
    $color_obj = ariColor::newColor( $color );
    // Set alpha (opacity) to 0.7
    $color_obj->alpha = 0.7;
    // return a CSS-formated rgba color
    return $color_obj->toCSS( 'rgba' );
}

or you could write it shorter like this:

function my_theme_get_semitransparent_color( $color ) {
    $color_obj = ariColor::newColor( $color );
    return $color_obj->getNew( 'alpha', .7 )->toCSS( 'rgba' );
}

or the same thing like this:

function my_theme_get_semitransparent_color( $color ) {
    $color_obj = ariColor::newColor( $color );
    $color_new = ariColor::newColor( 'rgba(' . $color_obj->red . ',' . $color_obj->green . ',' . $color_obj->blue . ',0.7)', 'rgba' );
    return $color_new->->toCSS( 'rgba' );
}

The choice is yours and you can manipulate colors in any way you want.

Properies list:

Methods:

newColor

Used to create a new object. Example: 

$color = ariColor::newColor( 'rgba(0, 33, 176, .62)' );

The newColor method has 2 arguments:

  1. $color: can accept any color value (see below for examples)
  2. $mode: the color mode. If undefined will be auto-detected.

Some example of acceptable formats for the color used in the 1st argument on the method:

'black'
'darkmagenta'
'#000'
'#000000'
'rgb(0, 0, 0)'
'rgba(0, 0, 0, 1)'
'hsl(0, 0%, 0%)'
'hsla(0, 0%, 0%, 1)'
array( 'rgba' => 'rgba(0,0,0,1)' )
array( 'color' => '#000000' )
array( 'color' => '#000000', 'alpha' => 1 )
array( 'color' => '#000000', 'opacity' => '1' )
array( 0, 0, 0, 1 )
array( 0, 0, 0 )
array( 'r' => 0, 'g' => '0', 'b' => 0 )
array( 'r' => 0, 'g' => '0', 'b' => 0, 'a' => 1 )
array( 'red' => 0, 'green' => 0, 'blue' => 0 )
array( 'red' => 0, 'green' => 0, 'blue' => 0, 'alpha' => 1 )
array( 'red' => 0, 'green' => 0, 'blue' => 0, 'opacity' => 1 )

And more! This way you can use the saved values from all known frameworks.

getNew

Used if we want to create a new object identical to the one we already have, but changing one of its properties.

The getNew method has 2 arguments:

  1. $property: can accept any of the properties listed above
  2. $value: the new value of the property.

Example 1: Darken a color by 10%

// Create a new object using rgba as our original color
$color = ariColor::newColor( 'rgba(0, 33, 176, .62)' );
// Darken the color by 10%
$dark = $color->getNew( 'lightness', $color->lightness - 10 );
// return HEX color
return $dark->toCSS( 'hex' );

Or you could write the above simpler like this by combining 2 steps:

$color = ariColor::newColor( 'rgba(0, 33, 176, .62)' );
return $color->getNew( 'lightness', $color->lightness - 10 )->toCSS( 'hex' )

Example 2: Remove any traces of green from an HSL color

// Create a new color object using an HSL color as source
$color = ariColor::newColor( 'hsl(200, 33%, 82%)' );
// I don't like green, color, let's remove any traces of green from that color
$new_color = $color->getNew( 'green', 0 );

toCSS

Returns a CSS-formatted color value.

The toCSS has a single argument:

  1. $mode: can accept any of the values listed below (defaults to hex if undefined)

Example:

// Create our instance
$color = ariColor::newColor( 'hsl(200, 33%, 82%)' );
// Get HEX color
$hex = $color->toCSS( 'hex' );
// Get RGB color
$rgb = $color->toCSS( 'rgb' );
// Get RGBA color
$rgba = $color->toCSS( 'rgba' );
// Get HSL color
$hsl = $color->toCSS( 'hsl' );
// Get HSLA color
$hsla = $color->toCSS( 'hsla' );

Color sanitization:

All colors are sanitized inside the class so you could easily write a proxy function that will always return a sanitized color like this:

/**
 * Sanitizes a CSS color.
 * 
 * @param $color  string   accepts all CSS-valid color formats
 * @return        string   the sanitized color
 */
function custom_color_sanitize( $color = '' ) {
    // If empty, return empty
    if ( '' == $color ) {
        return '';
    }
    // If transparent, return 'transparent'
    if ( is_string( $color ) && 'transparent' == trim( $color ) ) {
        return 'transparent';
    }
    // Instantiate the object
    $color_obj = ariColor::newColor( $color );
    // Return a CSS value, using the auto-detected mode
    return $color_obj->toCSS( $color_obj->mode );
}

You can even use a function like this one as a sanitize_callback in a customizer control :)