How do I convert longhand hex to RGB(A)?
For example, I have the following code to convert all formats of hex, colorname, etc.. to RGBA for background opacity, but for some reason longhand hex does not work, but instead takes the shorthand from the longhand (eg. background-color: #0000ff; becomes background-color: #000;).
Alot of the code below is based off of Convert hex color to RGB values in PHP but that question and similar questions are not able to resolve my issue. I spent 2 weeks looking for an answer to this, and have yet to find one, so I come here.
Color name to hex function:
function color_name_to_hex($color_name) {
$colors = array(
'aliceblue'=>'F0F8FF',
'antiquewhite'=>'FAEBD7',
'aqua'=>'00FFFF',
'aquamarine'=>'7FFFD4',
'azure'=>'F0FFFF',
'beige'=>'F5F5DC',
'bisque'=>'FFE4C4',
'black'=>'000000',
'blanchedalmond '=>'FFEBCD',
'blue'=>'0000FF',
'blueviolet'=>'8A2BE2',
'brown'=>'A52A2A',
'burlywood'=>'DEB887',
'cadetblue'=>'5F9EA0',
'chartreuse'=>'7FFF00',
'chocolate'=>'D2691E',
'coral'=>'FF7F50',
'cornflowerblue'=>'6495ED',
'cornsilk'=>'FFF8DC',
'crimson'=>'DC143C',
'cyan'=>'00FFFF',
'darkblue'=>'00008B',
'darkcyan'=>'008B8B',
'darkgoldenrod'=>'B8860B',
'darkgray'=>'A9A9A9',
'darkgreen'=>'006400',
'darkgrey'=>'A9A9A9',
'darkkhaki'=>'BDB76B',
'darkmagenta'=>'8B008B',
'darkolivegreen'=>'556B2F',
'darkorange'=>'FF8C00',
'darkorchid'=>'9932CC',
'darkred'=>'8B0000',
'darksalmon'=>'E9967A',
'darkseagreen'=>'8FBC8F',
'darkslateblue'=>'483D8B',
'darkslategray'=>'2F4F4F',
'darkslategrey'=>'2F4F4F',
'darkturquoise'=>'00CED1',
'darkviolet'=>'9400D3',
'deeppink'=>'FF1493',
'deepskyblue'=>'00BFFF',
'dimgray'=>'696969',
'dimgrey'=>'696969',
'dodgerblue'=>'1E90FF',
'firebrick'=>'B22222',
'floralwhite'=>'FFFAF0',
'forestgreen'=>'228B22',
'fuchsia'=>'FF00FF',
'gainsboro'=>'DCDCDC',
'ghostwhite'=>'F8F8FF',
'gold'=>'FFD700',
'goldenrod'=>'DAA520',
'gray'=>'808080',
'green'=>'008000',
'greenyellow'=>'ADFF2F',
'grey'=>'808080',
'honeydew'=>'F0FFF0',
'hotpink'=>'FF69B4',
'indianred'=>'CD5C5C',
'indigo'=>'4B0082',
'ivory'=>'FFFFF0',
'khaki'=>'F0E68C',
'lavender'=>'E6E6FA',
'lavenderblush'=>'FFF0F5',
'lawngreen'=>'7CFC00',
'lemonchiffon'=>'FFFACD',
'lightblue'=>'ADD8E6',
'lightcoral'=>'F08080',
'lightcyan'=>'E0FFFF',
'lightgoldenrodyellow'=>'FAFAD2',
'lightgray'=>'D3D3D3',
'lightgreen'=>'90EE90',
'lightgrey'=>'D3D3D3',
'lightpink'=>'FFB6C1',
'lightsalmon'=>'FFA07A',
'lightseagreen'=>'20B2AA',
'lightskyblue'=>'87CEFA',
'lightslategray'=>'778899',
'lightslategrey'=>'778899',
'lightsteelblue'=>'B0C4DE',
'lightyellow'=>'FFFFE0',
'lime'=>'00FF00',
'limegreen'=>'32CD32',
'linen'=>'FAF0E6',
'magenta'=>'FF00FF',
'maroon'=>'800000',
'mediumaquamarine'=>'66CDAA',
'mediumblue'=>'0000CD',
'mediumorchid'=>'BA55D3',
'mediumpurple'=>'9370D0',
'mediumseagreen'=>'3CB371',
'mediumslateblue'=>'7B68EE',
'mediumspringgreen'=>'00FA9A',
'mediumturquoise'=>'48D1CC',
'mediumvioletred'=>'C71585',
'midnightblue'=>'191970',
'mintcream'=>'F5FFFA',
'mistyrose'=>'FFE4E1',
'moccasin'=>'FFE4B5',
'navajowhite'=>'FFDEAD',
'navy'=>'000080',
'oldlace'=>'FDF5E6',
'olive'=>'808000',
'olivedrab'=>'6B8E23',
'orange'=>'FFA500',
'orangered'=>'FF4500',
'orchid'=>'DA70D6',
'palegoldenrod'=>'EEE8AA',
'palegreen'=>'98FB98',
'paleturquoise'=>'AFEEEE',
'palevioletred'=>'DB7093',
'papayawhip'=>'FFEFD5',
'peachpuff'=>'FFDAB9',
'peru'=>'CD853F',
'pink'=>'FFC0CB',
'plum'=>'DDA0DD',
'powderblue'=>'B0E0E6',
'purple'=>'800080',
'red'=>'FF0000',
'rosybrown'=>'BC8F8F',
'royalblue'=>'4169E1',
'saddlebrown'=>'8B4513',
'salmon'=>'FA8072',
'sandybrown'=>'F4A460',
'seagreen'=>'2E8B57',
'seashell'=>'FFF5EE',
'sienna'=>'A0522D',
'silver'=>'C0C0C0',
'skyblue'=>'87CEEB',
'slateblue'=>'6A5ACD',
'slategray'=>'708090',
'slategrey'=>'708090',
'snow'=>'FFFAFA',
'springgreen'=>'00FF7F',
'steelblue'=>'4682B4',
'tan'=>'D2B48C',
'teal'=>'008080',
'thistle'=>'D8BFD8',
'tomato'=>'FF6347',
'turquoise'=>'40E0D0',
'violet'=>'EE82EE',
'wheat'=>'F5DEB3',
'white'=>'FFFFFF',
'whitesmoke'=>'F5F5F5',
'yellow'=>'FFFF00',
'yellowgreen'=>'9ACD32');
$color_name = strtolower($color_name);
if (isset($colors[$color_name]))
{
return ('#' . $colors[$color_name]);
}
else
{
return ($color_name);
}
}
Get that function and don’t do if already RGB:
$content__background_color = '#0000FF';
if(strpos($content__background_color, 'rgb') !== false){
$rgbarr = explode(",",$content__background_color,3);
$colorname = sprintf("#%02x%02x%02x", $rgbarr[0], $rgbarr[1], $rgbarr[2]);
} else {
$colorname = self::color_name_to_hex($content__background_color);
}
Convert to RGBA:
list($r, $g, $b) = array_map(function($c){return hexdec(str_pad($c, 2, $c));}, str_split(ltrim($colorname, '#'), strlen($colorname > 4 ? 2 : 1)));
$send_to_less_example[ 'content-opacity-level' ] = "rgba($r, $g, $b, " . '75' / 100.00 . ')';
return $send_to_less_example;
Any ideas would be greatly appreciated.
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Answer
The algorithm is fine, you just have a wrong closing parenthesis at strlen($colorname > 4 ? 2 : 1) it should be strlen($colorname) > 4 ? 2 : 1 so change it to be like this and you’ll have it working:
list($r, $g, $b) = array_map(
function($c) {
return hexdec(str_pad($c, 2, $c));
},
str_split(ltrim($colorname, '#'), strlen($colorname) > 4 ? 2 : 1)
);
You can see it working at sandbox.onlinephpfunctions.com.