@rapid7/prisma
v4.0.2
Published
String-to-color generator
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prisma
A simple string-to-color conversion tool. The string provided generates a unique and consistent color, and an immutable object of the various valid HTML color values are returned.
prisma
has no dependencies, and has a tiny footprint of only 1.6kb (minified and gzipped).
Installation
Install via npm:
$ npm i @rapid7/prisma --save
and incorporate into your project:
// ES2015
import prisma from '@rapid7/prisma';
// CommonJS
const prisma = require('@rapid7/prisma').default;
// UMD
const prisma = window.prisma;
Usage
Simply pass a value to the prisma
function, and it will return an object with the hashed color information:
const colorizedString = prisma('Hello World!');
/* colorizedString is now the object:
{
hex: '#7e7be2',
hsl: 'hsl(242, 64%, 68%)',
hslArray: [242, 0.64, 0.68],
hsla: 'hsla(242, 64%, 68%, 1)',
hslaArray: [242, 0.64, 0.68, 1],
rgb: 'rgb(126, 123, 226)',
rgbArray: [126, 123, 226],
rgba: 'rgba(126, 123, 226, 1)',
rgbaArray: [126, 123, 226, 1],
shouldTextBeDark: false,
shouldTextBeDarkW3C: true
}
*/
Additionally, you can pass an object of options to the call:
const colorizedStringWithOptions = prisma('Hello World!', {
brightnessThreshold: 135,
defaultHex: '1d1d1d',
opacity: 0.5
});
/* colorizedStringWithOptions is now the object:
{
hex: '#7e7be2',
hsl: 'hsl(242, 64%, 68%)',
hslArray: [242, 0.64, 0.68],
hsla: 'hsla(242, 64%, 68%, 0.5)',
hslaArray: [242, 0.64, 0.68, 0.5],
rgb: 'rgb(126, 123, 226)',
rgbArray: [126, 123, 226],
rgba: 'rgba(126, 123, 226, 0.5)',
rgbaArray: [126, 123, 226, 0.5],
shouldTextBeDark: false,
shouldTextBeDarkW3C: true
}
*/
Options
brightnessThreshold
Numeric brightness value used as comparator when calculating shouldTextBeDark
, where brightness values greater than or equal to the number provided will return true
. Valid values are between 0 and 255, with the recommended range between 128 and 145.
- Default =
130
- Good =
140
- Bad =
"140"
defaultHex
Hexadecimal code that is the given default for empty strings. Shorthand values or with preceding hash is allowed.
- Default =
000000
- Good =
ffffff
- Good =
#fff
- Bad =
red
opacity
Numeric opacity value used in rgba
and hsla
(note that these are the only two colors impacted by opacity).
- Default =
1
- Good =
0.5
- Bad =
50
- Bad =
-0.6
Object properties returned
hex {string}
The hexadecimal color code as a string used in CSS
hsl {string}
The computed values for HSL (hue, saturation, luminance) as a string used in CSS
hslArray {Array<number>}
The computed values for HSL as an array of numbers
hsla {string}
The computed values for HSLA (hue, saturation, luminance, alpha of opacity) as a string used in CSS
hslaArray {Array<number>}
The computed values for HSLA as an array of numbers
rgb {string}
The Computed values for RGB (red, green, blue) as a string used in CSS
rgbArray {Array<number>}
The computed values for RGB as an array of numbers
rgba {string}
The Computed values for RGBA (red, green, blue, alpha of opacity) as a string used in CSS
rgbaArray {Array<number>}
The computed values for RGBA as an array of numbers
shouldTextBeDark {boolean}
Boolean value denoting if using this color as a background-color on an element, should the foreground text color be dark. This is based on an opinionated gamma value threshold.
shouldTextBeDarkW3C {boolean}
Boolean value denoting if using this color as a background-color on an element, should the foreground text color be dark. This is based on the W3C Relative Luminance Definition that is defined in the W3 spec.
Additional functions
prisma.shouldTextBeDark(hexColor: string[, brightnessThreshold: number]) returns {boolean}
Pass a hexadecimal color to it (with or without leading hash), and it returns whether the foreground text should be dark or not based on brightness level.
prisma.shouldTextBeDark('#000'); // false
prisma.shouldTextBeDark('ffffff'); // true
prisma.shouldTextBeDarkW3C(hexColor: string[, brightnessThreshold: number]) returns {boolean}
Pass a hexadecimal color to it (with or without leading hash), and it returns whether the foreground text should be dark or not based on the W3C standard.
prisma.shouldTextBeDarkW3C('#000'); // false
prisma.shouldTextBeDarkW3C('ffffff'); // true
How does it work?
Internally the string is hashed using a simple bitwise operation, and the resultant integer is converted into a hexadecimal code that the other values are built from. Because the hash is a bitwise operation based on charCodeAt, the consistency of the hash is guaranteed, and therefore the resultant colors are as well.
Development
Clone the git repository, and run npm install
. From there, you can run any of the following npm scripts:
build
= builds the library withNODE_ENV=development
and with source maps, outputting to thedist
folderbuild:minified
= builds the library withNODE_ENV=production
and minified, outputting tot thedist
folderdev
= runs the playground React application to seeprisma
in action. Have fun playing!lint
= runs ESLint against the files insrc
prepublish
= runslint
,transpile
,build
, andbuild-minified
transpile
= runs babel to transpile the files insrc
to an ES5-compliant version in thelib
folder