magazine-service/service-import-export/app/service/handle.js

'use strict';

const Service = require('egg').Service;
const xlsx = require('xlsx');
const fs = require('fs');
class HandleService extends Service {
  constructor(ctx) {
    super(ctx);
    this.progressModel = this.ctx.model.Progress;
    this.config = this.app.config;
  }
  // 导入处理
  async import({ type, taskId }) {
    const files = this.ctx.request.files[0];
    const workbook = xlsx.readFile(files.filepath);
    const name = workbook.SheetNames[0];
    const sheet = workbook.Sheets[name];
    const data = xlsx.utils.sheet_to_json(sheet);
    const total = data.length;
    let progress = 0;
    for (let i = 0; i < data.length; i++) {
      // 此处根据类型调用不同的数据存储服务
      const item = data[i];
      const fun = this.ctx.service.imperts[`import${type}`];
      await fun({ item, _this: this });
      // 此处调用进度存储
      progress = (i + 1) / total * 100;
      await this.ctx.service.progress.updateProgress({ taskId, progress, type });
    }
  }
  // 导出处理
  async export({ type, taskId, filters, ids, fileType }) {
    // 创建过滤条件
    const filter = {};
    let res;
    // 默认总数
    let total = (ids && ids.length) || 0;
    // 如果条件存在
    if (filters) {
      filter.$or = [];
      for (const i in filters) {
        const data = `{ "${i}": { "$regex": "${filters[i]}" } }`;
        filter.$or.push(JSON.parse(data));
      }
      // 获取查询总数函数
      const totalfun = this.ctx.service.total[`total${type}`];
      // 赋值总数
      total = await totalfun({ ...filter, _this: this });
    }
    // 获取查询函数
    const fun = this.ctx.service.exports[`exports${type}`];
    // 计算页数
    const pages = Math.ceil(total / 10);
    // 此处调用创建文件
    const file = await this.establishFile({ taskId, type, fileType });
    if (file === 'success') {
      for (let i = 0; i < pages; i++) {
        // 进度
        const progress = (i + 1) / pages * 100;
        // 更新进度
        await this.ctx.service.progress.updateProgress({ taskId, progress, type });
        // 调用查询数据函数
        res = await fun({ skip: i, filter, ids, _this: this });
        // 此处调用写入文件
        if (res.length <= 0) return;
        await this.insertFile({ type, data: res, taskId, fileType });
      }
    }
  }
  // 创建文件
  async establishFile({ taskId, type, fileType }) {
    const fun = this.ctx.service[fileType].establish;
    return await fun({ fileName: taskId, type, _this: this });
  }
  // 持续写入文件
  async insertFile({ type, data, taskId, fileType }) {
    const fun = this.ctx.service[fileType].insertFile;
    await fun({ type, fileName: taskId, data, _this: this });
  }
  // 模板下载
  async template({ type, fileType, fileName }) {
    const fun = this.ctx.service.template[fileType];
    const url = await fun({ fileName, type, _this: this });
    const postfix = url.split('.')[1];
    this.ctx.attachment(`${fileName}.${postfix}`);
    return fs.createReadStream(url);
  }
  // 文件下载
  async exportsDownload({ taskId, fileName }) {
    const url = `${this.app.config.exportsPath}/${taskId}.xlsx`;
    const postfix = url.split('.')[1];
    this.ctx.attachment(`${fileName}.${postfix}`);
    return fs.createReadStream(url);
  }
}

module.exports = HandleService;