Google可视化API示例中的“无效的JSON字符串”

I am roughly following this example. But must be doing something silly...

我粗略地遵循这个例子。但一定要做些傻事......

The server side Django view code:

服务器端Django查看代码:

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

These are the values of the variables copy-pasted from the pydev debugger: (Im using strings for each description field type just for testing)

这些是从pydev调试器复制粘贴的变量的值:(我只是为每个描述字段类型使用字符串进行测试)

description:

[("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 (generated by the google api):

json(由谷歌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'}]}]}

The client side javascript code that receives the json:

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});

This causes the following error on constructing the DataTable object (second line):

这会导致构造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

I understood that the whole clue was making sure that the schema format matches the data format but this seems to be the case. It must be something simple.

我知道整个线索是确保模式格式与数据格式匹配,但似乎是这种情况。它必须是简单的东西。

4 个解决方案

#1

Unfortunately I can't comment so this isn't exactly a full answer, but could you try eval'ing the JSON before trying to use it for the chart?

不幸的是我不能评论所以这不完全是一个完整的答案,但是你可以尝试在尝试将它用于图表之前评估JSON吗?

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

I think that may have solved this problem for me in the past; it may not be the safest way to go about it, but you could at least try it for testing.

我想这可能在过去为我解决了这个问题;它可能不是最安全的方法,但你至少可以尝试进行测试。

Alternatively, perhaps play with simplejson to dump your json string from the python instead of just returning the gviz string?

或者,也许玩simplejson从python转储你的json字符串而不是只返回gviz字符串?

#2

Make sure you put 'unsafe-eval' for script sources in Content-Security-Policy.

确保在Content-Security-Policy中为脚本源添加“unsafe-eval”。

A policy I use for Google Maps and Google Charts:

我用于Google地图和Google Charts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;
  "
/>

#3

JSON parsers should require field names to be delimited by double quotes, as outlined in the specification JSON RFC 4627:

JSON解析器应该要求字段名称用双引号分隔,如规范JSON RFC 4627中所述:

An object is an unordered collection of zero or more name/value pairs, where a name is a string [...] A string begins and ends with quotation marks.

对象是零个或多个名称/值对的无序集合,其中名称是字符串[...]字符串以引号开头和结尾。

So, the JSON should be formatted like this:

因此,JSON应该格式如下:

{
    "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" 
                } 
            ] 
        } 
    ]
}

#4

Had the same issue, even when stripping the options to an empty dictionary (resulting in the error "Invalid JSON string: {}" ...). Turns out the issue is with the script-src CSP, documented here: https://github.com/keen/keen-js/issues/394

有同样的问题,即使将选项剥离到空字典(导致错误“无效的JSON字符串:{}”...)。事实证明问题在于script-src CSP,在此处记录:https://github.com/keen/keen-js/issues/394

"Solution" is to add unsafe-eval to the CSP.

“解决方案”是将不安全评估添加到CSP。

#1