TRY CODING FUN

function previewFile() {
  const preview = document.querySelector('img');
  const file = document.querySelector('input[type=file]').files[0];
  const reader = new FileReader();

  reader.addEventListener("load", function () {
    // convert image file to base64 string
    preview.src = reader.result;
  }, false);

  if (file) {
    reader.readAsDataURL(file);
  }
}

//Step 1: Get the file from the input element
inputElement.onchange = function (event) {
  var file = event.target.files[0];

  //Step 2: Read the file using file reader
  var fileReader = new FileReader();

  fileReader.onload = function () {
    //Step 4:turn array buffer into typed array
    var typedarray = new Uint8Array(this.result);

    //Step 5:pdfjs should be able to read this
    const loadingTask = pdfjsLib.getDocument(typedarray);
    loadingTask.promise.then((pdf) => {
      // The document is loaded here...
    });
  };
  //Step 3:Read the file as ArrayBuffer
  fileReader.readAsArrayBuffer(file);
};

var reader = new FileReader();
    reader.readAsArrayBuffer(input.files[0]);
    reader.onload = function (e) {

     var myData = new Uint8Array(e.target.result)
	 var docInitParams = { data: myData };

	 PDFJS.getDocument(docInitParams).then(function(pdf) {.....})

}

const findData = await Assets.findOne({
  where: {
    barCode: {
      [Op.like]: `%${getCode}%`,
    },
  },
});

function isValidHttpUrl(string) {
  let url;

  try {
    url = new URL(string);
  } catch (_) {
    return false;
  }

  return url.protocol === 'http:' || url.protocol === 'https:';
}

function validURL(str) {
  var pattern = new RegExp(
    '^(https?:\\/\\/)?' + // protocol
      '((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|' + // domain name
      '((\\d{1,3}\\.){3}\\d{1,3}))' + // OR ip (v4) address
      '(\\:\\d+)?(\\/[-a-z\\d%_.~+]*)*' + // port and path
      '(\\?[;&a-z\\d%_.~+=-]*)?' + // query string
      '(\\#[-a-z\\d_]*)?$',
    'i'
  ); // fragment locator
  return !!pattern.test(str);
}

function isHTML(str) {
  var a = document.createElement('div');
  a.innerHTML = str;

  for (var c = a.childNodes, i = c.length; i--; ) {
    if (c[i].nodeType == 1) return true;
  }

  return false;
}

// 反转义 bug@& 这样的字符
export function HTMLDecode(text) {
  var temp = document.createElement('div');
  temp.innerHTML = text;
  var output = temp.innerText || temp.textContent;
  temp = null;
  return output;
}

import {
  Controller,
  Post,
  Body,
  UseInterceptors,
  UploadedFile,
  UploadedFiles,
  Request,
  UseGuards,
  StreamableFile,
  Get,
  Response,
  Param,
} from '@nestjs/common';
import { FileInterceptor, FilesInterceptor } from '@nestjs/platform-express';

// 单文件 + 其他字段
@Post('uploadPdf')
@UseInterceptors(FileInterceptor('pdf', { dest: './uploads' }))
async uploadPdf(@UploadedFile() file, @Body() body) {
  console.log(file, body);
}

// 多文件 + 其他字段
@Post('upload')
@UseInterceptors(FileFieldsInterceptor([
  { name: 'avatar', maxCount: 1 },
  { name: 'background', maxCount: 1 },
]))
uploadFile(@UploadedFiles() files: { avatar?: Express.Multer.File[], background?: Express.Multer.File[] }) {
  console.log(files);
}