docs.sheetjs.com/docz/docs/03-demos/04-static/10-astro.md
2023-04-24 04:50:42 -04:00

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AstroJS demos/net/index demos/mobile/index

:::note

This demo uses "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 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.

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:

/// <reference types="astro/client" />
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

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:

---
/* -- 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<IPresident>(wb.Sheets[wb.SheetNames[0]]);
---
<html>
  <body>
    <h3>Presidents</h3>
    <table>
      <thead><tr><th>Name</th><th>Index</th></tr></thead>
      {/* Display each row object as a TR within the TBODY element */}
      <tbody>{data.map(row => (
        <tr><td>{row.Name}</td><td>{row.Index}</td></tr>
      ))}</tbody>
    </table>
  </body>
</html>

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

:::

  1. Disable Astro telemetry:
npx astro telemetry disable
  1. Create a new site using the docs template:
npm create astro@latest -- --template docs --yes ./sheetjs-astro
cd sheetjs-astro
  1. Fetch the example file pres.numbers:
mkdir -p src/data
curl -Lo src/data/pres.numbers https://sheetjs.com/pres.numbers
  1. Install the SheetJS library:
npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
  1. Replace src/pages/index.astro with the following:
---
/* -- 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<IPresident>(wb.Sheets[wb.SheetNames[0]]);
---
<html>
  <body>
    <h3>Presidents</h3>
    <table>
      <thead><tr><th>Name</th><th>Index</th></tr></thead>
      <tbody>
      {data.map(row => (<tr>
        <td>{row.Name}</td><td>{row.Index}</td>
      </tr>))}
      </tbody>
    </table>
  </body>
</html>
  1. Append the following lines to 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;
}
  1. Add the highlighted lines to 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: [
  1. Build the static site:
npx astro build

AstroJS will place the generated site in the dist subfolder.

  1. Start a web server to host the static site:
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.