A password strength checker plugin for jQuery

passwdchkr.js

// Usage: $('input.pwstrnth').pwstrnth();

// Password strength checker plugin
;(function ($, window, undefined) {
  var pluginName = 'pwstrnth',
      document = window.document,
      indicators = [' ', ':\'(', ':(', ':|', ':)', ':D'],
      regexes = [/.{8,}/, /[a-z]+/, /[0-9]+/, /[A-Z]+/, /[\/?<>,.\[\]{}()*&^%$#@!;:|]/];

  function Plugin(element) {
    this.$element = $(element);
    this.init();
  };

  Plugin.prototype = {
      init: function() {
        var self = this;
        this.id = this.$element.attr('id') || this.$element.attr('name');
        this.$indicatorBox = $('<span id="' + this.id  + '-pwstrnth" class="pwstrnth-indicator">&nbsp;</span>');
        this.$element.after(this.$indicatorBox);
        this.indicator();
        this.$element.keyup(function() {
          self.indicator();
        });
      },
      indicator: function() {
        var value = this.$element.attr('value');
        if (this.$element.attr('value').length > 0) {
          this.$indicatorBox.text(indicators[this.strength(value)]);
          if (!this.$indicatorBox.is(':visible')) {
            this.$indicatorBox.fadeIn();
          }
        } else {
          this.$indicatorBox.fadeOut();
        }
      },
      strength: function(value) {
        var strength = 0;
        jQuery.each(regexes, function(i, regex) {
          if (value.match(regex)) {
             strength++;
          }
        });
        return strength
      }
  };

  $.fn[pluginName] = function () {
    return this.each(function () {
      if (!$.data(this, 'plugin_' + pluginName)) {
        $.data(this, 'plugin_' + pluginName,
          new Plugin(this));
      }
    });
  }
}(jQuery, window));