使用基于下拉列表的更新图表

Update Chart Using based on Dropdown list

我正在尝试根据 selecting 特定日期标准呈现图表。当我 select 从下拉列表中选择一个选项(例如每月)时,我希望图表呈现不同的数据集。

目前,下面的脚本没有执行上面的预期输出(当我从 selection 列表中 select daily/monthly 时它没有显示任何数据)。我在下面的代码中遗漏了什么吗?请指教

这是我的代码:

var dataDaily = [
    ['CVR', 'TALK'],
    [90, 353]
];

var dataWeekly = [
    ['CVR', 'TALK'],
    [225, 893]
];

var dataMonthly = [
    ['CVR', 'TALK'],
    [1602, 4934]  
];

$(function () {
    
    // Initial chart
    var chart = c3.generate({
        data: {
            rows: dataDaily,
            type: 'pie'
        }
    });
    
    // Redraw chart depending on which option is selected
    $("#DataType").change(function (evt) {
        var timeSelection = $("#DataType").val();
        var chart = c3.generate({
            data: {
                rows: timeSelection,
                type: 'pie' 
            }
        });
    });
    
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/c3/0.4.10/c3.min.js"></script>
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/c3/0.4.10/c3.min.css">
<select id="DataType">
  <option value="dataDaily">Daily</option>
  <option value="dataWeekly">Weekly</option>
  <option value="dataMonthly">Monthly</option>
</select>
<div id="chart"></div>

您还可以在这个 JSFiddle 上看到代码(和问题)的演示:http://jsfiddle.net/km97cdL3/

问题出在这一行:

var timeSelection = $("#DataType").val();

下拉列表的值是一个字符串("dataDaily"、"dataWeekly" 或 "dataMonthly"),而不是该文字字符串指定的数组变量(dataDaily , dataWeekly, 或 dataMonthly).

一个快速的解决方案是评估(使用 eval())select 的值,这样您就可以将字符串 "transform" 放入同名数组中:

var timeSelection = eval( $("#DataType").val() );

因此最终代码如下所示:

var dataDaily = [
    ['CVR', 'TALK'],
    [90, 353]
];

var dataWeekly = [
    ['CVR', 'TALK'],
    [225, 893]
];

var dataMonthly = [
    ['CVR', 'TALK'],
    [1602, 4934]  
];

$(function () {
    
    // Initial chart
    var chart = c3.generate({
        data: {
            rows: dataDaily,
            type: 'pie'
        }
    });
    
    // Redraw chart depending on which option is selected
    $("#DataType").change(function (evt) {
        var timeSelection = eval( $("#DataType").val() );
        var chart = c3.generate({
            data: {
                rows: timeSelection,
                type: 'pie' 
            }
        });
    });
    
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/c3/0.4.10/c3.min.js"></script>
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/c3/0.4.10/c3.min.css">

<select id="DataType">
  <option value="dataDaily">Daily</option>
  <option value="dataWeekly">Weekly</option>
  <option value="dataMonthly">Monthly</option>
</select>
<div id="chart"></div>

您还可以在这个 JSFiddle 上看到它正常工作:http://jsfiddle.net/km97cdL3/1/

注意:在开始使用eval()之前,您应该了解使用不当的风险。 Check this question and the comments for more details.