javascript - Chart.js 在折线图上绘制两个 json 数据集

Question

我正在尝试研究如何使用 Chart.js 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？日期会转到正确的标签上，这样就不会重复了吗？

具体来说，我正在努力将 "competition one" 放入 dataset 数组的 label (label: "竞赛一")

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

然后您只需将这些值操作成您想要的对象结构。

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:...});   
}