A title-case filter for AngularJs

title-case-filter.js

(function() {
    'use strict';

    angular
        .module('appName')
        .filter('titlecase', titlecase);

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

        input = input.toLowerCase();
        return input.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);
        });
        };
    }
})();

Updated to follow John Papa's style guide.