@devath/angular-excel-tools

XLSX (SheetJS) utilities for Angular apps. Provides a simple ExcelService to import .xlsx files into arrays-of-arrays (AOA) and export data back to Excel. Includes helpers for Angular Material tables. Designed to work with Angular 18.

Why this package

• Minimal API: read, sanitize, align headers, export.
• AOA-first: easy to map to your own models.
• MatTable helpers: import/export with table-friendly shapes.

Live demo

• StackBlitz template: https://stackblitz.com/fork/angular
• After it opens, run: npm i @devath/angular-excel-tools xlsx
• Paste the Quick start example below into app.component.ts

Install

npm i @devath/angular-excel-tools xlsx

Peer dependencies: @angular/common@^18, @angular/core@^18, xlsx@^0.18.5.

Quick start

Import and use the ExcelService in any component or service.

// example.component.ts
import { Component } from '@angular/core';
import { ExcelService, ImportResult } from '@devath/angular-excel-tools';

@Component({
  selector: 'app-example',
  template: `
    <input type="file" accept=".xlsx,.xls" (change)="onFile($event)" />
    <button (click)="exportSample()">Export sample</button>
  `
})
export class ExampleComponent {
  constructor(private excel: ExcelService) {}

  async onFile(ev: Event) {
    const input = ev.target as HTMLInputElement;
    const file = input.files?.[0];
    if (!file) return;
    const result: ImportResult = await this.excel.readFile(file);
    console.log(result.sheetNames); // ["Sheet1", ...]
    console.log(result.sheets["Sheet1"]); // AOA data
  }

  exportSample() {
    const aoa = [
      ['Name', 'Age'],
      ['Alice', 30],
      ['Bob', 28]
    ];
    this.excel.exportToXlsx({ data: aoa, filename: 'people.xlsx' });
  }
}

You can also export multiple sheets by passing an object of sheet names to AOA data:

this.excel.exportToXlsx({
  data: {
    Summary: [['Metric', 'Value'], ['Count', 2]],
    People:  [['Name', 'Age'], ['Alice', 30], ['Bob', 28]]
  },
  filename: 'report.xlsx'
});

Angular Material helpers

Helpers convert AOA ↔ MatTable-friendly shapes.

import { aoaToMatTable, matTableToAoa } from '@devath/angular-excel-tools';

const { displayedColumns, rows } = aoaToMatTable(aoa);
// bind: <table mat-table [dataSource]="rows"> ...

const aoaOut = matTableToAoa(displayedColumns, rows);

Use cases

• Import user-provided spreadsheets into your app.
• Export table data to Excel for reporting.
• Normalize messy sheets with header alignment.

API

• ExcelService.readFile(file): Promise
  • Reads an Excel file and returns { sheetNames: string[], sheets: Record<string, AOA> }.
• ExcelService.exportToXlsx({ data, filename })
  • data: AOA for a single sheet or Record<string, AOA> for multiple sheets.
  • filename: optional, defaults to export.xlsx.
• ExcelService.sanitizeAOA(aoa)
  • Normalizes rows to the same length, trims strings, replaces undefined with null.
• ExcelService.alignHeaders(aoa, headers)
  • Reorders columns of imported data to match your desired header order.
• aoaToMatTable(aoa)
  • Converts AOA (first row is headers) to { displayedColumns, rows }.
• matTableToAoa(displayedColumns, rows)
  • Converts MatTable inputs to AOA.

Types:

• AOA: (string | number | boolean | null | undefined)[][]
• ImportResult: { sheetNames: string[]; sheets: Record<string, AOA>; }

Tips

• Use sanitizeAOA right after import to ensure consistent row lengths.
• Use alignHeaders to map user-provided sheets to your required schema.

Angular compatibility

• Built with Angular 18 and Ivy partial compilation. Should work in Angular 16+ projects using Ivy.

License

MIT © Sandesh Ath