javascript - 使用 Chart.js 和关联数组生成条形图

Question

我有关联数组，我想使用 Chart.JS 库显示它。

My Array:

array:4 [▼
  0 => array:3 [▼
    "faculty" => "Information Technology"
    "category" => "ELearning"
    "counter" => 2
  ]
  1 => array:3 [▼
    "faculty" => "Information Technology"
    "category" => "Webex"
    "counter" => 2
  ]
  2 => array:3 [▼
    "faculty" => "Masscom"
    "category" => "ELearning"
    "counter" => 3
  ]
  3 => array:3 [▼
    "faculty" => "Masscom"
    "category" => "Webex"
    "counter" => 3
  ]
]

What I am trying to do:

我试图展示: - 底部的功能作为标签 - 对于每个教师，我想显示所有类别及其计数器

例如:

1) 信息技术具有值(value)为 2 的电子学习类别，并且具有值(value)为 2 的 Webex 类别

2) Masscom 具有值为 3 的 ELearning 类别，并且具有值为 3 的 Webex 类别

JS Code:

var faculties = ['Information Technology', 'Masscom'];
var f = document.getElementById("mybarChart");
new Chart(f, {
    type: "bar",
    data: {
       labels: faculties,
       datasets: ....
    },
})

Answer 1

本质上，您需要为每个类别提供一个数据集。每个数据集都需要每个教师的数据条目。

使用下面的代码，您将得到一个如下所示的图表:

// this will get distinct faculty and sort
const faculties = [...new Set(data.map(v => v['faculty']))].sort();

// this will get distinct category and sort
const categories = [...new Set(data.map(v => v['category']))].sort();

const datasets = categories.map(category => ({
  label: category,
  data: faculties.map(faculty => {
    const value = data.find(v => v['faculty'] === faculty && v['category'] === category);

    return value['counter'];
  })
}));

const canvas = document.getElementById('mybarChart');

new Chart(canvas, {
  type: 'bar',
  data: {
    labels: faculties,
    datasets: datasets
  }
});

我创建了一个 jsfiddle 到 show the code running .