如何创建一个快速创建 Excel 文件的 Nodejs 工具

核心使用 node-xlsx 模块

1.定义 ExcelCreator.js 模块

const xlsx = require('node-xlsx').default;
const fs = require('fs');
class ExcelCreator{
    constructor(opts) {
        let {filePath,sheets} = opts;     
        this.filePath_ = filePath;
        this.sheets_ = sheets;
    }
    build(){
        let buffer = xlsx.build(this.sheets_); // Returns a buffer
        fs.writeFile(this.filePath_, buffer,  "binary",function(err) { });
    }
}
module.exports = ExcelCreator;

2.定义 SheetDataCreator.js 模块

class SheetDataCreator{
    constructor(opts = {}) {
        let {rowLen,colLen,cell,calcConf} = opts;     
        this.rowLen_ = rowLen;
        this.colLen_ = colLen;
        this.cell_ = cell;
        this.calcConf_ = calcConf;
        this.cellTextLength_ = this.cell_ && this.cell_.text.length;
    }
    getCellTextDesc(){
        if(this.cell_.textFixed){
            return `文本固定${this.cell_.text.length}个字符`;
        }
        return '';
    }
    buildFileName(opts = {}){
        const {fileExt = 'xlsx'} = opts;
        
        const prefix = `EP-${this.rowLen_}行-${this.colLen_}列-${this.rowLen_*this.colLen_}个单元格`;
        if(this.calcConf_){
            return `${prefix}包含计算公式${this.calcConf_.expressing}.${fileExt}`
        }
        return `${prefix}${this.getCellTextDesc()}.${fileExt}`
    }
    getRandomCellDataForCalc(rowIndex,colIndex){
        if(rowIndex===0){
            return colIndex;
        }
        return {f:`=${this.calcConf_.expressing}(A1:L1)`};
    }
    getRandomCellData(rowIndex,colIndex){
        if(this.calcConf_){
                return this.getRandomCellDataForCalc(rowIndex,colIndex);
        }
        if(this.cell_ && this.cell_.text){
            if(this.cell_.textFixed){
                return this.cell_.text;
            }
            if(this.cellTextLength_){
                let end = parseInt(Math.random(0,1) * this.cellTextLength_);
                return this.cell_.text.substr(parseInt(end*Math.random(0,1)), end);
            }
        }
    }
    getCellsData(){
        let result = [];
        for (let i = 0; i < this.rowLen_; i++) {
           let rowData = [];
           for (let j = 0; j < this.colLen_; j++) {
                rowData.push(this.getRandomCellData(i,j))
           }
           result.push(rowData);
        }
        return result;
    }
    buildSheets(){
       let cellsData = this.getCellsData();
       let result = [{ name: "mySheetName", data: cellsData }];
    //    console.log(result)
       return result;

    }
}
module.exports = SheetDataCreator;

3.按指定特性创建 xlsx 文件

const fs = require('fs');
const path = require('path');
const ExcelCreator = require('./lib/ExcelCreator');
const SheetDataCreator = require('./lib/SheetDataCreator');

const sd = new SheetDataCreator({
    "rowLen": 2500, //行数
    "colLen": 10, //列数
    "calcConf": {
        "expressing": "SUM" //计算公式配置
    },
    "cell": {
        text: 'none' //文本内容
    }
});

let ec = new ExcelCreator({
    filePath: path.join('cal-output', sd.buildFileName({
        fileExt: 'xlsx',
    })), //配置输出目录
    sheets: sd.buildSheets() //构建表格
});
ec.build(); //执行任务