Echarts 5 动态按需引入图表

官网提供的按需引入方法为全量按需引入，在打包分离中，仍旧存在使用不到的图表被打包进去。

例如：组件A使用了折线图、柱状图，组件B只用到了折线图，但是打包组件B的时候，柱状图也就被打包进去。

本文提供一种动态按需引入的思路，使得只用到折线图的组件B，打包的时候只打包折线图，不会将组件A用到的柱状图也打包进去。

目录结构：

Index.ts 如下：

// 引入 echarts 核心模块，核心模块提供了 echarts 使用必须要的接口。
import * as ECHARTS from "echarts/core";
import type { ComposeOption } from "echarts/core";
import CORE, { CORE_ECOption } from "./Core";
import { LineChart_ECOption } from "./LineChart";
import { BarChart_ECOption } from "./BarChart";
import { RadarChart_ECOption } from "./RadarChart";

// 通过 ComposeOption 来组合出一个只有必须组件和图表的 Option 类型
export type ECOption = ComposeOption<CORE_ECOption | LineChart_ECOption | BarChart_ECOption | RadarChart_ECOption>;

class Echarts {
    public echarts: any;
    constructor(type: string[], callback: any) {
        // 注册必须的组件
        ECHARTS.use([...CORE]);

        const charts: any = [];

        type!.map((item: any) => {
            const res: any = import(/* webpackChunkName: "echarts" */ `./${item}`);
            charts.push(res);
        });

        Promise.all(charts).then((res: any) => {
            res.map((item: any) => {
                ECHARTS.use(item.default);
            });
            callback(ECHARTS);
        });
    }
}

export default Echarts;

Core.ts 如下：

// 引入标题，提示框，直角坐标系，数据集，内置数据转换器组件，组件后缀都为 Component
import {
    TitleComponent,
    TooltipComponent,
    GridComponent,
    DatasetComponent,
    TransformComponent,
    ToolboxComponent,
    LegendComponent
} from "echarts/components";

// 标签自动布局、全局过渡动画等特性
import { LabelLayout, UniversalTransition } from "echarts/features";

// 组件类型的定义后缀都为 ComponentOption
import type {
    TitleComponentOption,
    TooltipComponentOption,
    GridComponentOption,
    DatasetComponentOption,
    ToolboxComponentOption,
    LegendComponentOption
} from "echarts/components";

// 引入 Canvas 渲染器，注意引入 CanvasRenderer 或者 SVGRenderer 是必须的一步
import { CanvasRenderer } from "echarts/renderers";

// 通过 ComposeOption 来组合出一个只有必须组件和图表的 Option 类型
export type CORE_ECOption =
    | TitleComponentOption
    | TooltipComponentOption
    | GridComponentOption
    | DatasetComponentOption
    | ToolboxComponentOption
    | LegendComponentOption;

const CORE = [
    TitleComponent,
    TooltipComponent,
    GridComponent,
    DatasetComponent,
    TransformComponent,
    ToolboxComponent,
    LegendComponent,
    LabelLayout,
    UniversalTransition,
    CanvasRenderer
];

export default CORE;

BarChart.ts 如下：

import { BarChart } from "echarts/charts";

// 系列类型的定义后缀都为 SeriesOption
import type { BarSeriesOption } from "echarts/charts";

export type BarChart_ECOption = BarSeriesOption;

export default BarChart;

LineChart.ts 如下:

import { LineChart } from "echarts/charts";

// 系列类型的定义后缀都为 SeriesOption
import type { LineSeriesOption } from "echarts/charts";

// 通过 ComposeOption 来组合出一个只有必须组件和图表的 Option 类型
export type LineChart_ECOption = LineSeriesOption;

export default LineChart;

RadarChart.ts 如下:

import { RadarChart } from "echarts/charts";

// 系列类型的定义后缀都为 SeriesOption
import type { RadarSeriesOption } from "echarts/charts";

// 组件类型的定义后缀都为 ComponentOption
import type { RadarComponentOption } from "echarts/components";

// 通过 ComposeOption 来组合出一个只有必须组件和图表的 Option 类型
export type RadarChart_ECOption = RadarComponentOption | RadarSeriesOption;

export default RadarChart;

如果项目中还用到其他图表类型，则按照具体需要引入即可。

可以根据具体业务进行调用封装，下面是封装的示例 util.ts:

import Echarts from "/echarts/Index";

export const renderEcharts = async (type: string[], dom: string, option: any = {}, callback?: any) => {
    if (!dom) return;

    new Echarts(type, (echart: any) => {
        const _dom: any = document.querySelector(dom);

        const echarts_instance = echart.init(_dom);

        echarts_instance.setOption(option);

        window.addEventListener("resize", function () {
            echarts_instance.resize();
            echarts_instance.clear();
            echarts_instance.setOption(option);
        });

        _dom?.addEventListener("touchend", () => {
            setTimeout(() => {
                echarts_instance.dispatchAction({
                    type: "hideTip"
                });
                echarts_instance.dispatchAction({
                    type: "updateAxisPointer"
                });
            }, 1000);
        });

        callback && callback(echarts_instance);
    });
};

具体调用：

let echarts_instance = null;
const options = {// 具体的option }
renderEcharts(["LineChart", "BarChart"], "#echarts_box",options, (instance) => {
    echarts_instance = instance;
});