@barchart/common-js/lang/formatter.js

Library of common JavaScript utilities

module.exports = (() => {
	'use strict';

	return {
		/**
		 * Formats a number into a string for display purposes.
		 *
		 * @function
		 * @public
		 * @param {number|null|undefined} value
		 * @param {number} digits
		 * @param {string=} thousandsSeparator
		 * @param {boolean=} useParenthesis
		 */
		numberToString(value, digits, thousandsSeparator, useParenthesis) {
			if (value === '' || value === undefined || value === null || isNaN(value)) {
				return '';
			}

			const applyParenthesis = value < 0 && useParenthesis === true;

			if (applyParenthesis) {
				value = 0 - value;
			}

			let returnRef = value.toFixed(digits);

			if (thousandsSeparator && !(value > -1000 && value < 1000)) {
				const length = returnRef.length;
				const negative = value < 0;

				let found = digits === 0;
				let counter = 0;

				const buffer = [];

				for (let i = (length - 1); !(i < 0); i--) {
					if (counter === 3 && !(negative && i === 0)) {
						buffer.unshift(thousandsSeparator);

						counter = 0;
					}

					const character = returnRef.charAt(i);

					buffer.unshift(character);

					if (found) {
						counter = counter + 1;
					} else if (character === '.') {
						found = true;
					}
				}

				if (applyParenthesis) {
					buffer.unshift('(');
					buffer.push(')');
				}

				returnRef = buffer.join('');
			} else if (applyParenthesis) {
				returnRef = '(' + returnRef + ')';
			}

			return returnRef;
		}
	};
})();