suggests your city and state based on the zip code

locationSuggest

// requires google maps api: "http://maps.google.com/maps/api/js?sensor=false"
// and of course jQuery

(function($){
  $.locationSuggest = function(el, options){
    var base = this;
    
    base.$el = $(el);
    base.el = el;
    
    base.$el.data("locationSuggest", base);
    
    base.init = function() {
      base.options = $.extend({},$.locationSuggest.defaultOptions, options);
      base.generateJQuerySelectors();
      base.bindZipListener();
    };

    base.generateJQuerySelectors = function() {
      // this goes through all the selectors and assigns them to their $ objects, so:
      // options.selectors.options_panel has a base.$options_panel equivelent.
      for (var key in base.options.selectors) {
        base['$' + key] = $(base.options.selectors[key]);
      }
    };

    base.bindZipListener = function() {
      base.$el.change(function(e) {
        var zip = $(e.target).attr('value');
        base.getLocation(zip);
        // if (zip.length === 5) {
          // base.getLocation(zip);
        // }
      });
    };

    base.displayResults = function(results) {
      var city_state = [base.getCity(results), base.getState(results)].join(', ')
      var result_container = 'span.location_results';
      $(result_container).remove();
      var $html = $("<span class='location_results'>" + city_state + "<a href='#wrong_city'>Not your city?</a></span>");
      base.$el.after($html);
      $(result_container).find('a').click(function(e) {
        base.$hidden_fields.removeClass('hidden');
        e.preventDefault();
      });
    };

    base.populateLocations = function(results) {
      base.$city_input.val(base.getCity(results));

      var state = base.getState(results);
      var select_vals = $.map(base.$state_input.find('option'), function(el) { return $(el).val(); });
      if ($.inArray(state, select_vals) != -1) {
        base.$state_input.val(state)
      }
    };

    base.getLocation = function(zip) {
      var geocoder = new google.maps.Geocoder();

      if (geocoder) {
        geocoder.geocode({ 'address': zip }, function (results, status) {
          if (status === google.maps.GeocoderStatus.OK) {
            base.displayResults(results);
            base.populateLocations(results);
          } else {
            log("Geocoding failed: " + status);
          }
        });
      }  
    };

    base.getCity = function(results) {
      return base.getAddressComponent(results, 'locality');
    };

    base.getState = function(results) {
      return base.getAddressComponent(results, 'administrative_area_level_1');
    };

    base.getAddressComponent = function(results, type) {
      var results_with_type = $.grep(results[0].address_components, function(v, i) {
        return (v.types[0] === type);
      });
      try {
        return results_with_type[0].short_name;
      } catch (err) {
        return type + ' unavailable';
      }
    };

    base.init();
  };
  
  $.locationSuggest.defaultOptions = {
    selectors: {
      hidden_fields: '.city_and_state',
      city_input: '#schedule_test_drive_city',
      state_input: '#schedule_test_drive_region'
    }
  };
  
  $.fn.locationSuggest = function(options){
    return this.each(function(){
      (new $.locationSuggest(this, options));
    });
  };
})(jQuery);