tools-for-js/lib/web/files.js

基于babel构建的JavaScript前端工具库

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.getBase64 = exports.downloadStream = exports.blobToText = void 0;
/*******
 * @description: 将txt的blob转文本内容
 * @author: 琴时
 * @param {*} blob
 * @return {*}
 */
var blobToText = exports.blobToText = function blobToText(blob) {
  return new Promise(function (resolve, reject) {
    if (typeof FileReader === 'undefined') {
      reject(new Error('浏览器不支持FileReader对象'));
      return;
    }
    var reader = new FileReader();
    reader.onload = function () {
      resolve(reader.result);
    };
    reader.onerror = function () {
      reject(new Error('无法读取Blob对象'));
    };
    if (blob.constructor !== File) {
      reject(new Error('该数据不是blob'));
      return;
    }
    reader.readAsText(blob);
  });
};

/*******
 * @description: 下载流文件
 * @author: 琴时
 * @param {*} stream 文件流
 * @param {String} fileName 文件名
 * @return {*}
 */
var downloadStream = exports.downloadStream = function downloadStream(stream, fileName) {
  try {
    if (typeof window === 'undefined') return;
    var fileTypeMime = {
      png: 'image/png',
      jpeg: 'image/jpeg',
      gif: 'image/gif',
      svg: 'image/svg+xml',
      tiff: 'image/tiff',
      doc: 'application/msword',
      docx: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
      txt: 'text/plain',
      pdf: 'application/pdf',
      mp4: 'video/mp4',
      mp3: 'audio/mpeg',
      rar: 'application/x-rar-compressed',
      html: 'text/html',
      xml: 'text/xml',
      json: 'application/json',
      css: 'text/css',
      js: 'text/javascript',
      ppt: 'application/vnd.ms-powerpoint',
      pptx: 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
      csv: 'text/csv',
      xls: 'application/vnd.ms-excel',
      xlsx: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
      zip: 'application/zip',
      '7z': 'application/x-7z-compressed'
    };
    var suffix = fileName.slice(fileName.indexOf('.') + 1); //获取文件后缀
    var blob = new Blob([stream], {
      type: fileTypeMime[suffix]
    }); //创建blob对象
    var aLink = document.createElement('a'); //创建a标签
    document.body.appendChild(aLink); //末尾添加新的子节点
    aLink.style.display = 'none'; //将a标签隐藏
    var blobURL = URL.createObjectURL(blob); //将blob转换成URL
    aLink.href = aLink.download = fileName; //配置下载文件名
    aLink.click(); //自动触发点击a标签[下载文件]
    document.body.removeChild(aLink); //移除a标签
    URL.revokeObjectURL(blobURL); // 释放blob URL地址
  } catch (error) {
    console.log('下载异常:', error.message);
  }
};

/*******
 * @description: 图片转base64
 * @author: 琴时
 * @param {File} fil
 * @return {*}
 */
var getBase64 = exports.getBase64 = function getBase64(file) {
  return new Promise(function (resolve, reject) {
    if (typeof FileReader === 'undefined') {
      reject(new Error('浏览器不支持FileReader对象'));
      return;
    }
    var reader = new FileReader();
    reader.readAsDataURL(file);
    reader.onload = function () {
      return resolve(reader.result);
    };
    reader.onerror = function (error) {
      return reject(error);
    };
  });
};