尝试在Magento中使用Google Map 路线的错误（未捕获的ReferenceError：google未定义）

我专门创建了一个路线模板文件，以利用Google方向 . 我的脚本在Magento外面工作 . 不幸的是，当我将脚本移动到page / directions.phtml控制台时，会返回以下错误：

“未捕获的ReferenceError：未定义谷歌”

当我尝试点击test来触发calcRoute（）函数时，我收到以下错误：

“未捕获的TypeError：无法调用未定义的方法'route'”

我认为这些错误与Google Maps API调用有关，但图形 Map 在页面上显示和运行正常 . 这些错误特别与调用google.maps.DirectionsService（）有关，用于定义下面显示的javascript第2行的directionsService和最后调用的directionsService.route . 两者都与方向有关 .

为什么 Map 会显示，但是当脚本在我的html测试中工作时，方向会抛出错误？我很困惑 .

Javascript

var directionDisplay;
  var directionsService = new google.maps.DirectionsService();
  var map;

  function directionsMap() {
    directionsDisplay = new google.maps.DirectionsRenderer();
    var chicago = new google.maps.LatLng(38.77627, -95.910965);
    var mapOptions = {
      zoom:4,
      mapTypeId: google.maps.MapTypeId.ROADMAP,
      center: chicago
    }
    map = new google.maps.Map(document.getElementById('map-directions'), mapOptions);
    directionsDisplay.setMap(map);

    //Place Markers
    var baldwinsvilleMarker = new google.maps.Marker({
        position: new google.maps.LatLng(00.00000, 00.00000),
        map: map,
        title:"store location 1"
    });
    var sacramentoMarker = new google.maps.Marker({
        position: new google.maps.LatLng(00.00000, 00.00000),
        map: map,
        title:"store location 2"
    });
    var stLouisMarker = new google.maps.Marker({
        position: new google.maps.LatLng(000.00000, -000.00000),
        map: map,
        title:"store location 3"
    });
    var catersvilleMarker = new google.maps.Marker({
        position: new google.maps.LatLng(00.000000, -84.000000),
        map: map,
        title:"store location 4"
    });

    directionsDisplay.setMap(map);
    directionsDisplay.setPanel(document.getElementById("get-directions"));

  }

  function calcRoute() {
    console.log("calcRoute ran")
    var start = document.getElementById('start').value;
    var end = document.getElementById('end').value;
    console.log(start + ' ' + end)
    var request = {
        origin:start,
        destination:end,
        travelMode: google.maps.DirectionsTravelMode.DRIVING
    };
    directionsService.route(request, function(response, status) {
      if (status == google.maps.DirectionsStatus.OK) {
        directionsDisplay.setDirections(response);
      }
    });
  }

HTML

#I am including this line in the document head
           <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
           <style onload="directionsMap()">
            #map-directions{width: 65%; height: 300px; float: left; border:5px solid #EEEEEE;}
            #get-directions{width: 65%; float: left;}
            .map-sidebar{width: 32%; height: 300px; float: right;}
            </style>

            <div id="map-directions"></div>
            <div class="map-sidebar">
                <h2>Get Directions</h2>

                <input type="text" id="start" value="chicago, il"/>
                <b>End: </b>
                <select id="end" onchange="calcRoute();">

                  <option value="value 1">
                      store location 1
                  </option>

                  <option value="value 2">
                      store location 2
                  </option>

                  <option value="value 3">
                      store location 3
                  </option>

                  <option value="value 4">
                      store location 4
                  </option>

                </select>
                <button onclick="calcRoute();"> test</button>


            </div>
            <div id="get-directions"></div>