图表中的堆积条形图.js包含 JSON 数据

Question

我有以下JSON数据。

[
  {
      "date": "2016-05-01T00:00:00",
      "productInformation": [
        {
            "productName": "Apple",
            "totalWeight": 200
        }
      ]
  },
  {
      "date": "2016-09-01T00:00:00",
      "productInformation": [
        {
            "productName": "Apple",
            "totalWeight": 632
        },
        {
            "productName": "Mango",
            "totalWeight": 856
        },
        {
            "productName": "Spinach",
            "totalWeight": 545
        },
        {
            "productName": "Grapes",
            "totalWeight": 338
        }
      ]
  },
  {
      "date": "2017-01-01T00:00:00",
      "productInformation": [
        {
            "productName": "Mango",
            "totalWeight": 500
        }
      ]
  }
]

在 X 轴上，我想显示月份和年份，在 Y 轴上，我想显示产品信息的堆叠条。 例如，在2016-05年，只有苹果，所以它只会显示苹果。在 2016-09 有 4 产品，因此它将根据 4 产品及其总重量显示 4 个质押条。我已经阅读了图表.js文档。根据文档，我必须在数据集中提供 Y 轴值。如何提取数据集的 Y 轴值以从给定的 JSON 数据创建堆叠条形图？如果我想从上面给出的 JSON 数据手动创建图表，那么它将是这样的。

var barChartData = {
labels: ["May 2016", "September 2016", "January 2017"],
datasets: [{
    label: "Apple",
    data: [200, 632, 0],
    backgroundColor: "#3c8dbc"
},
{
    label: "Mango",
    data: [0,856,500],
    backgroundColor: "#3c8dbc"
},
{
    label: "Spinach",
    data: [0,545,0],
    backgroundColor: "#3c8dbc"
},
{
    label: "Grapes",
    data: [0,338,0],
    backgroundColor: "#3c8dbc"
}]
};

我需要一种方法data从给定的 JSON 数据中提取数据集的一部分。

Answer 1

这个代码片段应该解决你问题中最困难的部分(使用 ES6 语法(：

const data = [{
  "date": "2016-05-01T00:00:00",
  "productInformation": [{
    "productName": "Apple",
    "totalWeight": 200
  }]
}, {
  "date": "2016-09-01T00:00:00",
  "productInformation": [{
    "productName": "Apple",
    "totalWeight": 632
  }, {
    "productName": "Mango",
    "totalWeight": 856
  }, {
    "productName": "Spinach",
    "totalWeight": 545
  }, {
    "productName": "Grapes",
    "totalWeight": 338
  }]
}, {
  "date": "2017-01-01T00:00:00",
  "productInformation": [{
    "productName": "Mango",
    "totalWeight": 500
  }]
}]
const uniq = a => [...new Set(a)]
const flatten = a => [].concat.apply([], a)
// step 1: find the distinct dates: ["2016-05-01T00:00:00", ... ]
const dates = data.map(e => e.date)
// step 2: find the distinct labels: [Apple, Mango, ... ]
const labels = uniq(
  flatten(data.map(e => e.productInformation))
  .map(e => e.productName))
// step 3: map the labels to entries containing their data by searching the original data array
const result = labels.map(label => {
  return {
    label,
    data: dates.map(date => {
      const hit = data.find(e => e.date === date)
        .productInformation
        .find(p => p.productName === label)
      return hit ? hit.totalWeight : 0
    })
  }
})
console.log(result)