Get object with computed styles from the node

get_computed_styles.js

/**
 * Return object with computed styles
 * @param  {DOMNode} node
 * @param  {String|Array} styles_to_get "float colot padding-top" or ["float", "padding-top", "padding-bottom"]
 * @return {Object} list of styles values {
 *    "float" : "none",
 *    "color" : "#000000"
 * }
 */
function get_computed_styles(node, styles_to_get) {
	'use strict';
	var res = {},
		current_styles,
		camel_case_style_name,
		second_param_type,
		i;

	// Get object, representing current styles
	if (node.currentStyle) {
		current_styles = node.currentStyle;
	} else if (window.getComputedStyle) {
		current_styles = window.getComputedStyle(node);
	} else {
		throw (new Error('get_computed_styles: could not get styles'));
	}

	second_param_type = Object.prototype.toString.call(styles_to_get);

	// Create array of styles to get, if possible
	if (styles_to_get) {
		if (second_param_type === '[object String]') {
			styles_to_get = styles_to_get.split(/\s+/);
		} else if (second_param_type !== '[object Array]') {
			throw (new Error('get_computed_styles: second param string or array expected, but got ' + second_param_type));
		}
		// Collect styles value into result object
		for (i = 0; i < styles_to_get.length; i += 1) {
			camel_case_style_name = styles_to_get[i].replace(/-(.)/, function (match, first_letter) {
				return first_letter.toUpperCase();
			});
			if (camel_case_style_name === 'float') {
				res[styles_to_get[i]] = current_styles.cssFloat || current_styles.styleFloat;
			} else {
				res[styles_to_get[i]] = current_styles[camel_case_style_name];
			}
		}
	} else {
		res = current_styles;
	}
	return res;
}