jodit/src/modules/helpers/color/colorToHex.ts

Jodit is awesome and usefully wysiwyg editor with filebrowser

/*!
 * Jodit Editor (https://xdsoft.net/jodit/)
 * Licensed under GNU General Public License version 2 or later or a commercial license or MIT;
 * For GPL see LICENSE-GPL.txt in the project root for license information.
 * For MIT see LICENSE-MIT.txt in the project root for license information.
 * For commercial licenses see https://xdsoft.net/jodit/commercial/
 * Copyright (c) 2013-2019 Valeriy Chupurnov. All rights reserved. https://xdsoft.net
 */

/**
 * Converts rgba text representation of color in hex
 * @param {string} color - string like rgba(red, green, blue, alpha) or rgb(red, green, blue)
 * @return {string | NaN} hex color view, NaN - for transparent color
 * @example
 * ```javascript
 * var p = document.createElement('p');
 * p.style.color = '#ffffff';
 * console.log(p.getAttribute('style')); // color: rgb(255, 255, 255);
 * console.log(colorTohex(p.style.color)); // #ffffff
 * ```
 */
export const colorToHex = (color: string): string | false => {
    if (color === 'rgba(0, 0, 0, 0)' || color === '') {
        return false;
    }

    if (!color) {
        return '#000000';
    }

    if (color.substr(0, 1) === '#') {
        return color;
    }

    const digits =
        /([\s\n\t\r]*?)rgb\((\d+), (\d+), (\d+)\)/.exec(color) ||
        /([\s\n\t\r]*?)rgba\((\d+), (\d+), (\d+), ([\d.]+)\)/.exec(color);
    let hex, red, green, blue, rgb;

    if (!digits) {
        return '#000000';
    }

    red = parseInt(digits[2], 10);
    green = parseInt(digits[3], 10);
    blue = parseInt(digits[4], 10);
    rgb = blue | (green << 8) | (red << 16);

    hex = rgb.toString(16).toUpperCase();

    while (hex.length < 6) {
        hex = '0' + hex;
    }

    return digits[1] + '#' + hex;
};