Question

我们有现有的休息Web服务生成json响应。现在我们想使用谷歌图表来显示这些数据。谷歌可视化API似乎期望自己的json格式。是否有任何退出的js方法/库将常规json对象转换为js对象的google可视化类型？谢谢。

Answer 1

这实际上取决于您的目标和数据，以及您想要使用的Google图表。在处理REST数据和谷歌图表时，我通常会执行以下操作。

在这个例子中，我使用jQuery，但你使用的js库并不相关。

假设您有以下数据集以及在areachart中显示的内容：

{"events":[{"event":{"timestamp":"1310926588423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926578423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926568423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926558423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926548423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926538423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926528423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926518423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926508423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}},{"event":{"timestamp":"1310926498423","service":"EsperEventProcessor.service","countAll3Sec_EsperEventProcessor":"0","server":"EsperServer"}}]}

要使用JQuery和JSONQuery（这可以帮助您轻松选择JSON数据中的特定内容），您可以执行以下操作：

  // use the getJSON jQuery operation to get the REST data
  $.getJSON(restURL, function(data) {

    // use jsonquery to get all the 'event's from the JSON data     
    var query1 = "..event";
    var rootEvent = JSONQuery(query1,data);

    // manually create a datatable and fill it in the required
    // way for this chart           
    var data2 = new google.visualization.DataTable();
    data2.addColumn('string', 'Number of queries / per 10 seconds');
    data2.addColumn('number', '# queries');

    // each row is added based on information from the json event
    // by simply iterating over the array
    data2.addRows(rootEvent.length);
    for (i = 0; i < rootEvent.length; i++) {
      var date = new Date(parseInt(rootEvent[i]['timestamp']));
      var hours = date.getHours();
      var minutes = date.getMinutes();
      var seconds = date.getSeconds();

      var time = '';
      if (hours < 10) time=time+'0'; time=time+hours+':';
      if (minutes < 10) time=time+'0'; time=time+minutes+':';
      if (seconds < 10) time=time+'0'; time=time+seconds;

      data2.setCell(i,0,time);
      data2.setCell(i,1,parseInt(rootEvent[i]['countAll3Sec_EsperEventProcessor']));
    }


    chart.draw(data2, {width: 400, height: 240, title: 'Requests per 10 seconds',
                       hAxis: {title: 'Time', titleTextStyle: {color: '#FF0000'}}
    });
 });

是否有一个退出的js方法/库将常规json对象转换为js对象的google可视化类型？

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