---
title: AstroJS
pagination_prev: demos/net/index
pagination_next: demos/mobile/index
---
import current from '/version.js';
:::note
This demo uses ["Base64 Loader"](/docs/demos/static/vitejs#base64-loader)
from the ViteJS demo.
:::
Astro is a site generator. Astro projects use ViteJS under the hood. They expose
project configuration through the `vite` property in `astro.config.mjs`. The
[ViteJS demo](/docs/demos/static/vitejs) examples work as expected!
## Integration
:::note
The ViteJS demo used the query `?b64` to identify files. To play nice with
Astro, this demo matches the file extensions directly.
:::
Since Astro performs per-page heavy lifting at build time, it is recommended to
use the Base64 string loader to get file data and parse with the SheetJS library
in the relevant pages. If the SheetJS operations are performed in frontmatter,
only the results will be added to the generated pages!
### Loader
The loader should be added to `astro.config.mjs` under the `vite` key.
```js title="astro.config.mjs"
import { readFileSync } from 'fs';
import { defineConfig } from 'astro/config';
export default defineConfig({
vite: {
// this tells astro which extensions to handle
assetsInclude: ['**/*.numbers', '**/*.xlsx'],
plugins: [
{ // this plugin presents the data as a Base64 string
name: "sheet-base64",
transform(code, id) {
if(!id.match(/\.(numbers|xlsx)$/)) return;
var data = readFileSync(id, "base64");
return `export default '${data}'`;
}
}
]
}
});
```
#### Types
For VSCodium integration, types can be specified in `src/env.d.ts`.
This data loader returns Base64 strings:
```ts title="src/env.d.ts"
///
declare module '*.numbers' {
const data: string;
export default data;
}
declare module '*.xlsx' {
const data: string;
export default data;
}
```
### Astro Frontmatter
Typically projects store files in `src/pages`. Assuming `pres.numbers` is stored
in the `src/data` directory in the project, the relative import
```js
import b64 from "../data/pres.numbers"
```
will return a Base64 string which can be parsed in the frontmatter. The workbook
object can be post-processed using utility functions. The following example
uses `sheet_to_json` to generate row objects that are rendered as table rows:
```jsx title="src/pages/index.astro"
---
/* -- the code in the frontmatter is only run at build time -- */
import { read, utils } from "xlsx";
/* parse workbook */
import b64 from "../data/pres.numbers";
const wb = read(b64, {type: "base64"});
/* generate row objects */
interface IPresident {
Name: string;
Index: number;
}
const data = utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
---
Presidents
| Name | Index |
|---|
{/* Display each row object as a TR within the TBODY element */}
{data.map(row => (
| {row.Name} | {row.Index} |
))}
```
When built using `npx astro build`, Astro will perform the conversion and emit
a simple HTML table without any reference to the existing spreadsheet file!
## Complete Example
:::note
This demo was tested on 2023 February 21 using AstroJS `v2.0.14`
:::
0) Disable Astro telemetry:
```bash
npx astro telemetry disable
```
1) Create a new site using the `docs` template:
```bash
npm create astro@latest -- --template docs --yes ./sheetjs-astro
cd sheetjs-astro
```
2) Fetch the example file [`pres.numbers`](https://sheetjs.com/pres.numbers):
```bash
mkdir -p src/data
curl -Lo src/data/pres.numbers https://sheetjs.com/pres.numbers
```
3) Install the SheetJS library:
{`\
npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz`}
4) Replace `src/pages/index.astro` with the following:
```jsx title="src/pages/index.astro"
---
/* -- the code in the frontmatter is only run at build time -- */
import { read, utils } from "xlsx";
/* parse workbook */
import b64 from "../data/pres.numbers";
const wb = read(b64, {type: "base64"});
/* generate row objects */
interface IPresident {
Name: string;
Index: number;
}
const data = utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
---
Presidents
| Name | Index |
|---|
{data.map(row => (
| {row.Name} | {row.Index} |
))}
```
5) Append the following lines to `src/env.d.ts`:
```ts title="src/env.d.ts"
/* add to the end of the file */
declare module '*.numbers' {
const data: string;
export default data;
}
declare module '*.xlsx' {
const data: string;
export default data;
}
```
6) Add the highlighted lines to `astro.config.mjs`:
```js title="astro.config.mjs"
// highlight-start
/* import `readFileSync` at the top of the script*/
import { readFileSync } from 'fs';
// highlight-end
import { defineConfig } from 'astro/config';
export default defineConfig({
// highlight-start
/* this vite section should be added as a property of the object */
vite: {
// this tells astro which extensions to handle
assetsInclude: ['**/*.numbers', '**/*.xlsx'],
plugins: [
{ // this plugin presents the data as a Base64 string
name: "sheet-base64",
transform(code, id) {
if(!id.match(/\.(numbers|xlsx)$/)) return;
var data = readFileSync(id, "base64");
return `export default '${data}'`;
}
}
]
},
// highlight-end
integrations: [
```
7) Build the static site:
```bash
npx astro build
```
AstroJS will place the generated site in the `dist` subfolder.
8) Start a web server to host the static site:
```bash
npx http-server dist
```
Open a web browser and access the displayed URL (usually http://localhost:8080).
View the page source and confirm that no JS was added to the page. It only
contains the content from the file in an HTML table.