numberFormat Handlebars helper

numberFormatHelper.js

/**
 * An Handlebars helper to format numbers
 * 
 * This helper have these three optional parameters:
 *  @var decimalLength int The length of the decimals
 *  @var thousandsSep char The thousands separator
 *  @var decimalSep char The decimals separator
 * 
 * Based on:
 *  - mu is too short: http://stackoverflow.com/a/14493552/369867
 *  - VisioN: http://stackoverflow.com/a/14428340/369867
 * 
 * Demo: http://jsfiddle.net/DennyLoko/6sR87/
 */
Handlebars.registerHelper('numberFormat', function (value, options) {
    // Helper parameters
    var dl = options.hash['decimalLength'] || 2;
    var ts = options.hash['thousandsSep'] || ',';
    var ds = options.hash['decimalSep'] || '.';

    // Parse to float
    var value = parseFloat(value);

    // The regex
    var re = '\\d(?=(\\d{3})+' + (dl > 0 ? '\\D' : '$') + ')';

    // Formats the number with the decimals
    var num = value.toFixed(Math.max(0, ~~dl));

    // Returns the formatted number
    return (ds ? num.replace('.', ds) : num).replace(new RegExp(re, 'g'), '$&' + ts);
});