TypeError: google.visualization.DataTable is not a constructor

Question

在我的网页上有一张 google 地图，以及三张图表。当页面加载地图时，地图很好，但图表要么不加载，要么只有一两个图表加载。不断收到错误 TypeError: google.visualization.DataTable is not a constructor。

function load() {
     //map object
        var MY_MAP = new google.maps.Map(document.getElementById("map"), {
        center: {lat: 54.870902, lng: -6.300565}, 
        zoom: 14
      });    
      //call to get and process data
      downloadUrl("Map.php", processXML);
  }  

 // Load the Visualization API and the piechart package.
      google.load('visualization', '1.0', {'packages':['corechart']}); 
        // Set a callback to run when the Google Visualization API is loaded. 
google.setOnLoadCallback(drawAltitudeChart());  
google.setOnLoadCallback(drawDisplacementChart());
google.setOnLoadCallback(drawDistanceChart());  



function drawAltitudeChart(){

         //console.log('hello');
         var graph = [];
          downloadUrl("Map.php", function (data){
              var xml = data.responseXML;
              var markers = xml.documentElement.getElementsByTagName("marker");
              var dataTable = new google.visualization.DataTable();
              var options = {title:'Altitude (m above sea level)', 
                  curveType:'function', 
                  legend:{position:'bottom'},
                  is3d:true     
              };
              var chart;

              for(var i = 0; i<markers.length; i++){
                  graph[i] = ['', parseInt(markers[i].getAttribute("alt"))];   
              }

              dataTable.addColumn('string', 'id');
              dataTable.addColumn('number', 'Altitude');
              dataTable.addRows(graph);


              chart = new google.visualization.LineChart(document.getElementById('curve_chart'));
              chart.draw(dataTable, options); 

          });
      }

Answer 1

我认为您不能添加多个这样的回调。

另外，你可以在load方法中定义回调，像这样...

google.load('visualization', '1.0', {'packages':['corechart'], 'callback': drawCharts});

function drawCharts() {
  drawAltitudeChart();
  drawDisplacementChart();
  drawDistanceChart();
}

编辑

上面的 load 语句是针对 older 图书馆...

<script src="http://www.google.com/jsapi"></script>

根据 release notes...

The version of Google Charts that remains available via the jsapi loader is no longer being updated consistently. Please use the new gstatic loader from now on.

使用新库...

<script src="https://www.gstatic.com/charts/loader.js"></script>

将 load 语句更改为...

google.charts.load('current', {'packages': ['corechart'], 'callback': drawCharts});

编辑 2

您还可以在一个 load 语句中加载您需要的所有包，例如
而不是...

google.charts.load('current', { 'packages': ['table'] });
google.charts.load('current', { 'packages': ['bar'] });
google.charts.load('current', { 'packages': ['pie'] });  // <-- 'pie' package does not exist
google.charts.load('current', { 'packages': ['corechart'] });
google.charts.setOnLoadCallback(drawCharts);

应该是……

google.charts.load('current', {
  callback: drawCharts,
  packages: ['bar', 'corechart', 'table']
});

Answer 2

我收到了同样的信息，只是因为我忘记加载包了

  // was -> google.charts.load('current', {'packages':['bar', 'corechart']});
  google.charts.load('current', {'packages':['bar', 'corechart', 'table']});

Answer 3

即使您使用正确的策略，即加载 google 图表并在加载事件上使用回调，也有必要将脚本保留在 head 标签中，这与我们将脚本保留在底部以防止页面加载缓慢。

我直接从 google 图表的文档中引用：

除了少数例外，所有带有 Google 图表的网页都应在网页的 <head> 中包含以下行：

<script src="https://www.gstatic.com/charts/loader.js"></script>
<script>
  google.charts.load('current', {packages: ['corechart']});
  google.charts.setOnLoadCallback(drawChart);
  ...
</script>

参考：Basic Chart Loading

P.S：我遵循了每个细节，但没有将加载脚本保留在 head 标记中，我连续遇到此错误 TypeError: google.visualization.arrayToDataTable is not a function。将脚本保留在 head 标签中解决了这个问题。

TypeError: google.visualization.DataTable is not a constructor

TypeError: google.visualization.DataTable is not a constructor

javascript

charts

google-visualization