Question

我正在尝试使用Chart.js

来确定如何将标签绘制到正确的位置

var json = {
    "competition one": [
        {
            "date": "2015-05-20",
            "position": 37
        },
        {
            "date": "2015-05-21",
            "position": 22
        }
    ],
    "competition two": [
        {
            "date": "2015-05-20",
            "position": 29
        },
        {
        "date": "2015-05-21",
        "position": 19
        }
    ]
}

如何将标签绘制到正确的位置？日期是否正确的标签，所以不重复？

具体来说，我很难将"competition one"加入label数组的dataset（label: "competition one"）

我需要它类似于Chart.js所需的以下数据结构吗？

var data = {
    labels: ["2015-05-20", "2015-05-21"],
    datasets: [
        {
            label: "competition one",
            data: [37, 22]
        },
        {
            label: "Competition two",
            data: [29, 19]
        }
    ]
};

Answer 1

如评论中所述，您可以获得如下属性名称：

var json = {
    "competition one": [
        {
            "date": "2015-05-20",
            "position": 37
        },
        {
            "date": "2015-05-21",
            "position": 22
        }
    ],
    "competition two": [
        {
            "date": "2015-05-20",
            "position": 29
        },
        {
        "date": "2015-05-21",
        "position": 19
        }
    ]
}

var keys = Object.keys(json);
for (var i = 0; i < keys.length; i++)
{
    var key = keys[i];
    //"competition one", "competition two", etc
    console.log(key);   
}

Fiddle

然后您只需要将这些值操作到您想要的对象结构中。

var keys = Object.keys(json);
//set up our object containing an array called datasets
var data = {datasets:[]};
for (var i = 0; i < keys.length; i++)
{
    var key = keys[i];
    //push the key into the dataset array as an object {}
    data.datasets.push({label:key, data:...});   
}

Chart.js在折线图上绘制两个json数据集

1 个答案:

Fiddle