Search code examples
javascriptangulartypescriptexport-to-excelexceljs

Angular : Can't export excel using ExcelJS - error TS2307: Cannot find module 'stream' - error TS2503: Cannot find namespace 'NodeJS'


I was try to export an excel file using ExcelJS

Here is my console in VS Code terminal :

ERROR in node_modules/exceljs/index.d.ts:1398:22 - error TS2307: Cannot find module 'stream'.

1398  read(stream: import('stream').Stream): Promise<Workbook>;
                          ~~~~~~~~
node_modules/exceljs/index.d.ts:1424:23 - error TS2307: Cannot find module 'stream'.

1424  write(stream: import('stream').Stream, options?: Partial<XlsxWriteOptions>): Promise<void>;
                           ~~~~~~~~
node_modules/exceljs/index.d.ts:1511:22 - error TS2307: Cannot find module 'stream'.

1511  read(stream: import('stream').Stream, options?: Partial<CsvReadOptions>): Promise<Worksheet>;
                          ~~~~~~~~
node_modules/exceljs/index.d.ts:1531:23 - error TS2307: Cannot find module 'stream'.

1531  write(stream: import('stream').Stream, options?: Partial<CsvWriteOptions>): Promise<void>;
                           ~~~~~~~~
node_modules/exceljs/index.d.ts:1828:19 - error TS2307: Cannot find module 'stream'.

1828            stream: import('stream').Stream;
                               ~~~~~~~~
node_modules/exceljs/index.d.ts:1872:34 - error TS2503: Cannot find namespace 'NodeJS'.

1872             dictionary: Buffer | NodeJS.TypedArray | DataView | ArrayBuffer; // deflate/inflate only, empty dictionary by default                                      ~~~~~~

here is app.component.html

<!DOCTYPE html>
<html lang="en">

<head>
  <title>Bootstrap Example</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <!-- <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css"> -->

  <!-- serial must : first jquery then popper then bootstrap -->
  <!-- <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script> -->


</head>

<body>

    <div class="row">

      <div class="col-md-2">
        <button class="btn btn-secondary" (click)='downloadExcel()'>Download as Excel</button>
      </div>

    </div>

</body>

</html>

here is app.component.ts

import { Component } from '@angular/core';
import * as Excel from 'exceljs';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'resttest10';

  async downloadExcel() {

    const date = new Date().toISOString().slice(0, 10).split('-').reverse().join('/');
    console.log(date);
    const workbook = new Excel.Workbook();
    const worksheet = workbook.addWorksheet('My Sheet');

    worksheet.columns = [
      { header: 'Id', key: 'id', width: 10 },
      { header: 'Name', key: 'name', width: 32 },
      { header: 'D.O.B.', key: 'dob', width: 15, }
    ];

    worksheet.addRow({ id: 1, name: 'John Doe', dob: new Date(1970, 1, 1) });
    worksheet.addRow({ id: 2, name: 'Jane Doe', dob: new Date(1965, 1, 7) });

    // save under export.xlsx
    await workbook.xlsx.writeFile('export.xlsx');

    // load a copy of export.xlsx
    const newWorkbook = new Excel.Workbook();
    await newWorkbook.xlsx.readFile('export.xlsx');

    const newworksheet = newWorkbook.getWorksheet('My Sheet');
    newworksheet.columns = [
      { header: 'Id', key: 'id', width: 10 },
      { header: 'Name', key: 'name', width: 32 },
      { header: 'D.O.B.', key: 'dob', width: 15, }
    ];
    await newworksheet.addRow({ id: 3, name: 'New Guy', dob: new Date(2000, 1, 1) });

    await newWorkbook.xlsx.writeFile('export2.xlsx');

    console.log('File is written');
  }
}

I don't get it why it is looking for stream module (and more funny thing - Cannot find namespace 'NodeJS' - I can run all other angular NodeJS projects without error)

Please point out why i can't export excel.


Solution

  • You can't write directly a file on client side. that method is mean to be used on backend side in nodejs. if your expectation is download this file on client side. your code should be like :-

    import { Component } from "@angular/core";
    import * as Excel from "exceljs";
    @Component({
      selector: "my-app",
      templateUrl: "./app.component.html",
      styleUrls: ["./app.component.css"]
    })
    export class AppComponent {
      title = "resttest10";
    
      async downloadExcel() {
        const date = new Date()
          .toISOString()
          .slice(0, 10)
          .split("-")
          .reverse()
          .join("/");
        console.log(date);
        const workbook = new Excel.Workbook();
        const worksheet = workbook.addWorksheet("My Sheet");
    
        worksheet.columns = [
          { header: "Id", key: "id", width: 10 },
          { header: "Name", key: "name", width: 32 },
          { header: "D.O.B.", key: "dob", width: 15 }
        ];
    
        worksheet.addRow({ id: 1, name: "John Doe", dob: new Date(1970, 1, 1) });
        worksheet.addRow({ id: 2, name: "Jane Doe", dob: new Date(1965, 1, 7) });
    
        workbook.xlsx.writeBuffer().then((data: any) => {
          console.log("buffer");
          const blob = new Blob([data], {
            type:
              "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
          });
          let url = window.URL.createObjectURL(blob);
          let a = document.createElement("a");
          document.body.appendChild(a);
          a.setAttribute("style", "display: none");
          a.href = url;
          a.download = "export.xlsx";
          a.click();
          window.URL.revokeObjectURL(url);
          a.remove();
        });
      }
    }