Google 可视化 API 示例中的“无效 JSON 字符串”

我大致如下这个例子 http://code.google.com/apis/chart/interactive/docs/dev/gviz_api_lib.html#tojsonexample。但一定是在做一些愚蠢的事情......

服务器端Django视图代码：

data_table = gviz_api.DataTable(description)
data_table.LoadData(data)
json = data_table.ToJSon()
return json

这些是从 pydev 调试器复制粘贴的变量值：（我对每个描述字段类型使用字符串只是为了测试）

描述：

[("sensor","string", "Sensor name"), 
 ("timestamp","string", "Time"),
 ("value","string", "Sensor value")]

data:

[['testsensor', '2011-05-09 16:06:43.936000', '22.0'],
['testsensor', '2011-05-09 16:56:23.367000', '23.0']]

json（由google api生成）：

{cols:[{id:'sensor',label:'Sensor name',type:'string'},{id:'timestamp',label:'Time',type:'string'},{id:'value',label:'Sensor value',type:'string'}],rows:[{c:[{v:'testsensor'},{v:'2011-05-09 16:06:43.936000'},{v:'22.0'}]},{c:[{v:'testsensor'},{v:'2011-05-09 16:56:23.367000'},{v:'23.0'}]}]}

接收json的客户端javascript代码：

var json_table = new google.visualization.Table(document.getElementById('dataview'));
var json_data = new google.visualization.DataTable(data, 0.6);
json_table.draw(json_data, {showRowNumber: true});

这会导致在构造 DataTable 对象时出现以下错误（第二行）：

Uncaught Error: Invalid JSON string: {cols:[{id:'sensor',label:'Sensor name',type:'string'},{id:'timestamp',label:'Time',type:'string'},{id:'value',label:'Sensor value',type:'string'}],rows:[{c:[{v:'testsensor'},{v:'2011-05-09 16:06:43.936000'},{v:'22.0'}]},{c:[{v:'testsensor'},{v:'2011-05-09 16:56:23.367000'},{v:'23.0'}]}]}
in default,table.I.js:152

我知道整个线索是确保架构格式与数据格式匹配，但情况似乎确实如此。这一定是简单的事情。

确保你把'unsafe-eval'对于脚本源Content-Security-Policy.

我用于 Google 地图和 Google 图表的政策：

<meta
  http-equiv="Content-Security-Policy"
  content="
    default-src 'self';
    script-src 'self' 'unsafe-inline' 'unsafe-eval' maps.googleapis.com www.google.com www.google-analytics.com;
    img-src 'self' csi.gstatic.com www.google-analytics.com maps.gstatic.com maps.googleapis.com;
    style-src 'self' 'unsafe-inline' www.google.com fonts.googleapis.com ajax.googleapis.com;
    font-src 'self' fonts.gstatic.com;
  "
/>