Question

我正在学习D3。我正在处理的示例之一包含在较旧版本的D3下编写的代码。我知道在5.7.0下数据加载的工作方式有所不同，但是对于此示例，我无法正确加载数据。当只加载数据（1个函数）时，我知道它是如何工作的，但是在此示例中，使用2个函数时，我无法解决该问题。

任何人都可以给我一些建议，以解决如何使其在最新版本的d3下工作吗？这是代码：

function show() {

'use strict';

// load the data
var loadedData;

d3.csv('./data/businessFiltered.csv').then(
    function(row) {
        switch (row.yearsInBusiness) {
            case "001" : row.yearsInBusinessLabel = "All"; break;
            case "311" : row.yearsInBusinessLabel = "less then 2 years"; break;
            case "318" : row.yearsInBusinessLabel = "2 to 3 years "; break;
            case "319" : row.yearsInBusinessLabel = "4 to 5 years"; break;
            case "321" : row.yearsInBusinessLabel = "6 to 10 years"; break;
            case "322" : row.yearsInBusinessLabel = "11 to 15 years"; break;
            case "323" : row.yearsInBusinessLabel = "more then 16 years"; break;
        }

        return row;
    },
    function (data) {
        loadedData = data;
        updateCircle();
    }); ...

Answer 1

看着the documentation for d3.csv()，看来您可以使用.get()指定一个回调函数：

function show() {

'use strict';

// load the data
var loadedData;

d3.csv('./data/businessFiltered.csv')
    .row(function(row) {
        switch (row.yearsInBusiness) {
            case "001" : row.yearsInBusinessLabel = "All"; break;
            case "311" : row.yearsInBusinessLabel = "less then 2 years"; break;
            case "318" : row.yearsInBusinessLabel = "2 to 3 years "; break;
            case "319" : row.yearsInBusinessLabel = "4 to 5 years"; break;
            case "321" : row.yearsInBusinessLabel = "6 to 10 years"; break;
            case "322" : row.yearsInBusinessLabel = "11 to 15 years"; break;
            case "323" : row.yearsInBusinessLabel = "more then 16 years"; break;
        }
        return row;
    })
    .get(function(error, data) {
        loadedData = data;
        updateCircle();
    });

Answer 2

经过更多的谷歌搜索和尝试之后，我似乎发现了在最新版本的D3（v5）中可以使用的功能：

function show() {

'use strict';

// load the data
var loadedData;

d3.csv('./data/businessFiltered.csv', function(row) {
        switch (row.yearsInBusiness) {
            case "001" : row.yearsInBusinessLabel = "All"; break;
            case "311" : row.yearsInBusinessLabel = "less then 2 years"; break;
            case "318" : row.yearsInBusinessLabel = "2 to 3 years "; break;
            case "319" : row.yearsInBusinessLabel = "4 to 5 years"; break;
            case "321" : row.yearsInBusinessLabel = "6 to 10 years"; break;
            case "322" : row.yearsInBusinessLabel = "11 to 15 years"; break;
            case "323" : row.yearsInBusinessLabel = "more then 16 years"; break;
        };
        return row;
    })
    .then(function(data) {
        loadedData = data;
        updateCircle();
    });

D3载入资料

2 个答案: