To Title Case for JavaScript

to-title-case.js

/* 
  * To Title Case 2.1 – http://individed.com/code/to-title-case/
  * Copyright © 2008–2013 David Gouch. Licensed under the MIT License.
 */

/*
 * modifications by @rvagg Apr-2014
 */

/* 
 * modifications by Rex Schrader Jun 2015
 */

var smallWords = /^(a|an|and|as|at|but|by|en|for|if|in|nor|of|on|or|per|the|to|vs?\.?|via)$/i;

function titleCase (str, smallWords) {
  if (!str)
    return str
  return str.replace(/[A-Za-z0-9\u00C0-\u00FF]+[^\s-]*/g, function(match, index, title){
    if (index > 0 && index + match.length !== title.length &&
      match.search(smallWords) > -1 && title.charAt(index - 2) !== ':' &&
      (title.charAt(index + match.length) !== '-' || title.charAt(index - 1) === '-') &&
      title.charAt(index - 1).search(/[^\s-]/) < 0) {
      return match.toLowerCase();
    }

    if (match.substr(1).search(/[A-Z]|\../) > -1) {
      return match;
    }

    return match.charAt(0).toUpperCase() + match.substr(1);
  });
}