---
title: Sheets in Angular Sites
sidebar_label: Angular
description: Build interactive websites with Angular. Seamlessly integrate spreadsheets into your app using SheetJS. Bring Excel-powered workflows and data to the modern web.
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---
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Angular is a JS library for building user interfaces.[^1]
[SheetJS](https://sheetjs.com) is a JavaScript library for reading and writing
data from spreadsheets.
This demo uses Angular and SheetJS to process and generate spreadsheets. We'll
explore how to load SheetJS in Angular projects and compare common state models
and data flow strategies.
:::note pass
This demo focuses on Angular concepts. Other demos cover general deployments:
- [iOS and Android applications powered by NativeScript](/docs/demos/mobile/nativescript)
- [iOS and Android applications powered by Ionic](/docs/demos/mobile/ionic)
:::
:::caution pass
Angular tooling uses native NodeJS modules. There are a number of issues when
trying to run Angular projects with different NodeJS versions. These issues
should be directed to the Angular project.
:::
:::warning Telemetry
Angular CLI enables telemetry by default. When using a recent version, disable
analytics globally through the CLI tool before creating a new project:
```bash
npx @angular/cli analytics disable -g
```
(If prompted to share data, type `N` and press Enter)
:::
## Installation
[The "Frameworks" section](/docs/getting-started/installation/frameworks) covers
installation with `pnpm` and other package managers.
The library can be imported directly from JS or TS code with:
```js
import { read, utils, writeFile } from 'xlsx';
```
## Internal State
The various SheetJS APIs work with various data shapes. The preferred state
depends on the application.
:::warning pass
Angular 17 broke backwards compatibility with projects using Angular 2 - 16.
**Despite the Angular turmoil, SheetJS plays nice with each version of Angular**.
When relevant, code snippets for Angular 17 and Angular 2 - 16 are included. The
"Angular 2-16" and "Angular 17+" tabs change the displayed code blocks
:::
### Array of Objects
Typically, some users will create a spreadsheet with source data that should be
loaded into the site. This sheet will have known columns.
#### State
The example [presidents sheet](https://sheetjs.com/pres.xlsx) has one header row
with "Name" and "Index" columns. The natural JS representation is an object for
each row, using the values in the first rows as keys:
This data is typically stored as an array of objects in the component class:
```ts
import { Component } from '@angular/core';
@Component({ /* ... component configuration options ... */ })
export class AppComponent {
/* the component state is an array of objects */
// highlight-next-line
rows: any[] = [ { Name: "SheetJS", Index: 0 }];
}
```
When the spreadsheet header row is known ahead of time, row typing is possible:
```ts
import { Component } from '@angular/core';
interface President {
Name: string;
Index: number;
}
@Component({ /* ... component configuration options ... */ })
export class AppComponent {
/* the component state is an array of presidents */
// highlight-next-line
rows: President[] = [ { Name: "SheetJS", Index: 0 }];
}
```
:::caution pass
The types are informative. They do not enforce that worksheets include the named
columns. A runtime data validation library should be used to verify the dataset.
When the file header is not known in advance, `any` should be used.
:::
#### Updating State
The SheetJS [`read`](/docs/api/parse-options) and [`sheet_to_json`](/docs/api/utilities/array#array-output)
functions simplify state updates. They are best used in the function bodies of
`ngOnInit`[^2] and event handlers.
A `ngOnInit` method can download and update state when a person loads the site:
```mermaid
flowchart LR
url[(Remote\nFile)]
ab[(Data\nArrayBuffer)]
wb(SheetJS\nWorkbook)
ws(SheetJS\nWorksheet)
aoo(array of\nobjects)
state((component\nstate))
url --> |fetch\n\n| ab
ab --> |read\n\n| wb
wb --> |wb.Sheets\nselect sheet| ws
ws --> |sheet_to_json\n\n| aoo
aoo --> |setPres\nfrom `setState`| state
```
```ts
import { Component } from '@angular/core';
import { read, utils } from 'xlsx';
interface President { Name: string; Index: number };
@Component({ /* ... component configuration options ... */ })
export class AppComponent {
rows: President[] = [ { Name: "SheetJS", Index: 0 }];
ngOnInit(): void { (async() => {
/* Download from https://sheetjs.com/pres.numbers */
const f = await fetch("https://sheetjs.com/pres.numbers");
const ab = await f.arrayBuffer();
// highlight-start
/* parse workbook */
const wb = read(ab);
/* generate array of objects from first worksheet */
const ws = wb.Sheets[wb.SheetNames[0]]; // get the first worksheet
const data = utils.sheet_to_json(ws); // generate objects
/* update data */
this.rows = data;
// highlight-end
})(); }
}
```
#### Rendering Data
Components typically render HTML tables from arrays of objects. The `
` table
row elements are typically generated by mapping over the state array, as shown
in the example template.
:::caution pass
Angular 2 - 16 recommended using `ngFor`[^3]. Angular 17 no longer supports the
storied syntax, instead opting for a `@for` block reminiscent of JavaScript[^4].
:::
```html title="Example Template for displaying arrays of objects (Angular 2-16)"
Name
Index
// highlight-start
{{row.Name}}
{{row.Index}}
// highlight-end
```
```html title="Example Template for displaying arrays of objects (Angular 17+)"
Name
Index
// highlight-start
@for(row of rows; track $index) {
{{row.Name}}
{{row.Index}}
}
// highlight-end
```
#### Exporting Data
The [`writeFile`](/docs/api/write-options) and [`json_to_sheet`](/docs/api/utilities/array#array-of-objects-input)
functions simplify exporting data. They are best used in the function bodies of
event handlers attached to button or other elements.
A callback can generate a local file when a user clicks a button:
```mermaid
flowchart LR
state((component\nstate))
ws(SheetJS\nWorksheet)
wb(SheetJS\nWorkbook)
file[(XLSX\nexport)]
state --> |json_to_sheet\n\n| ws
ws --> |book_new\nbook_append_sheet| wb
wb --> |writeFile\n\n| file
```
```ts title="src/app/app.component.ts"
import { Component } from '@angular/core';
import { utils, writeFileXLSX } from 'xlsx';
interface President { Name: string; Index: number };
@Component({ /* ... component configuration options ... */ })
export class AppComponent {
rows: President[] = [ { Name: "SheetJS", Index: 0 }];
/* get state data and export to XLSX */
onSave(): void {
/* generate worksheet from state */
// highlight-next-line
const ws = utils.json_to_sheet(this.rows);
/* create workbook and append worksheet */
const wb = utils.book_new();
utils.book_append_sheet(wb, ws, "Data");
/* export to XLSX */
writeFileXLSX(wb, "SheetJSAngularAoO.xlsx");
}
}
```
#### Complete Component
This complete component example fetches a test file and displays the contents in
a HTML table. When the export button is clicked, a callback will export a file:
```ts title="src/app/app.component.ts"
import { Component } from '@angular/core';
import { read, utils, writeFileXLSX } from 'xlsx';
interface President { Name: string; Index: number };
@Component({
selector: 'app-root',
template: `
Name
Index
// highlight-start
{{row.Name}}
{{row.Index}}
// highlight-end
`
})
export class AppComponent {
// highlight-next-line
rows: President[] = [ { Name: "SheetJS", Index: 0 }];
ngOnInit(): void { (async() => {
/* Download from https://sheetjs.com/pres.numbers */
const f = await fetch("https://sheetjs.com/pres.numbers");
const ab = await f.arrayBuffer();
/* parse workbook */
// highlight-next-line
const wb = read(ab);
/* update data */
// highlight-next-line
this.rows = utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
})(); }
/* get state data and export to XLSX */
onSave(): void {
// highlight-next-line
const ws = utils.json_to_sheet(this.rows);
const wb = utils.book_new();
utils.book_append_sheet(wb, ws, "Data");
writeFileXLSX(wb, "SheetJSAngularAoO.xlsx");
}
}
```
```ts title="src/app/app.component.ts"
import { Component } from '@angular/core';
import { read, utils, writeFileXLSX } from 'xlsx';
interface President { Name: string; Index: number };
@Component({
selector: 'app-root',
standalone: true,
template: `
Name
Index
// highlight-start
@for(row of rows; track $index) {
{{row.Name}}
{{row.Index}}
}
// highlight-end
`
})
export class AppComponent {
// highlight-next-line
rows: President[] = [ { Name: "SheetJS", Index: 0 }];
ngOnInit(): void { (async() => {
/* Download from https://sheetjs.com/pres.numbers */
const f = await fetch("https://sheetjs.com/pres.numbers");
const ab = await f.arrayBuffer();
/* parse workbook */
// highlight-next-line
const wb = read(ab);
/* update data */
// highlight-next-line
this.rows = utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
})(); }
/* get state data and export to XLSX */
onSave(): void {
// highlight-next-line
const ws = utils.json_to_sheet(this.rows);
const wb = utils.book_new();
utils.book_append_sheet(wb, ws, "Data");
writeFileXLSX(wb, "SheetJSAngularAoO.xlsx");
}
}
```
How to run the example (click to hide)
:::note Tested Deployments
This demo was tested in the following environments:
| Angular | Date |
|:----------|:-----------|
| `17.3.0` | 2024-03-13 |
| `16.2.12` | 2024-03-13 |
:::
0) Disable telemetry:
```bash
npx @angular/cli analytics disable -g
```
1) Create a new project:
```bash
npx @angular/cli@17.3.0 new --minimal --defaults --no-interactive sheetjs-angular
```
:::note pass
The `@angular/cli` version controls the project version of Angular. For example,
the following command uses Angular 16.2.12:
```bash
npx @angular/cli@16.2.12 new --minimal --defaults --no-interactive sheetjs-angular
```
:::
2) Install the SheetJS dependency and start the dev server:
{`\
cd sheetjs-angular
npm i
npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz
npx @angular/cli analytics disable
npm start`}
3) Open a web browser and access the displayed URL (`http://localhost:4200`)
4) In the previous `src/app/app.component.ts` code snippet, select the tab for
the appropriate version of Angular ("Angular 2-16" or "Angular 17+"), copy the
code contents and replace `src/app/app.component.ts` in the project.
The page will refresh and show a table with an Export button. Click the button
and the page will attempt to download `SheetJSAngularAoO.xlsx`. Open the file
with a spreadsheet editor.
5) Stop the dev server and build the site:
```bash
npm run build
```
To test the generated site, start a web server:
```bash
npx -y http-server dist/sheetjs-angular/
```
```bash
npx -y http-server dist/sheetjs-angular/browser/
```
Access the displayed URL (typically `http://localhost:8080`) with a web browser
to test the bundled site.
### HTML
The main disadvantage of the Array of Objects approach is the specific nature
of the columns. For more general use, passing around an Array of Arrays works.
However, this does not handle merge cells well!
The `sheet_to_html` function generates HTML that is aware of merges and other
worksheet features. The generated HTML does not contain any `